Modifiers of TGF-β1 effector function as novel therapeutic targets of pulmonary fibrosis

LncRNA MRAK052509 competitively adsorbs miR-204-3p to regulate silica dust-induced EMT process

Silicosis is a systemic disease caused by long-term inhalation of free SiO2 and retention in the lungs. At present, it is still the most important occupational health hazard disease in the world. Existing studies have shown that non-coding RNA can also participate in complex fibrosis regulatory networks. However, its role in regulating silicotic fibrosis is still unclear. In this study, we constructed a NR8383/RLE-6TN co-culture system to simulate the pathogenesis of silicosis in vitro. Design of miR-204-3p mimics and inhibitors to overexpress or downregulate miR-204-3p in RLE-6TN cells. Design of short hairpin RNA (sh-RNA) to downregulate MRAK052509 in RLE-6TN cells. The regulatory mechanism of miR-204-3p and LncRNA MRAK052509 on EMT process was studied by Quantitative real-time PCR, Western blotting, Immunofluorescence and Cell scratch test. The results revealed that miR-204-3p affects the occurrence of silica dust-induced cellular EMT process mainly through regulating TGF-βRΙ, a key molecule of TGF-β signaling pathway. In contrast, Lnc MRAK052509 promotes the EMT process in epithelial cells by competitively adsorbing miR-204-3p and reducing its inhibitory effect on the target gene TGF-βRΙ, which may influence the development of silicosis fibrosis. This study perfects the targeted regulation relationship between LncRNA MRAK052509, miR-204-3p and TGF-βRΙ, and may provide a new strategy for the study of the pathogenesis and treatment of silicosis.

Characteristics of Interstitial Pneumonia With Autoimmune Features (IPAF): Protocol for a Multicenter Prospective Study

BACKGROUND

"Interstitial lung disease" (ILD) is a broad term encompassing diseases of different backgrounds. "Interstitial pneumonia with autoimmune features" (IPAF) is a recent term that implies the presence of autoimmunity.

OBJECTIVE

This study aims to determine the characteristics of Polish patients with IPAF, compare them with patients with other interstitial pneumonias, and search for the prognostic and diagnostic biomarkers of IPAF in serum and bronchoalveolar lavage fluid (BALF).

METHODS

This multicenter prospective study plans to recruit 240 participants divided into 1 study group and 2 control groups. Biological fluid samples will be collected according to Polish Respiratory Society management guidelines and stored at -80°C for further tests. Prospective 5-year observations of 60 newly diagnosed individuals are planned. The study will be divided into subsections. First, we plan to characterize Polish patients with IPAF (study group) against their peers with other ILDs (2 control groups). Control group 1 will comprise patients with idiopathic ILDs, including mainly idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia. Control group 2 will comprise patients with connective tissue disease-associated interstitial lung diseases, such as rheumatoid arthritis, systemic sclerosis, polymyositis, dermatomyositis, Sjögren's syndrome, mixed connective tissue disease, and systemic lupus erythematosus. Radiological and functional parameters will be analyzed. Patients will be compared in terms of high-resolution computed tomography results, the 6-minute walking test performance, and pulmonary function test parameters. The diagnosis of IPAF will be reassessed on a regular basis through multidisciplinary discussion in order to determine its clinical stability. In the laboratory arm, inflammation and fibrosis pathways will be assessed. Cytokine levels (interleukin 8, transforming growth factor beta 1, chemokine C-C motif ligand [CXCL]18, CXCL1, surfactant protein [SP]-A, SP-D, Krebs von den Lungen-6 protein, and chitinase 1) will be measured in serum and BALF. A comparative analysis of serum and BALF cytokine levels will be performed in order to establish potential differences between systemic and local inflammatory pathways. In the quality of life (QoL) arm of the study, dyspnea and cough and their impact on various aspects of the QoL will be assessed. Depression and anxiety will be measured with the Hospital Anxiety and Depression Modified Scale and the 9-item Patient Health Questionnaire, and potential correlations with symptom prevalence will be assessed.

RESULTS

This study will start recruiting patients to phase 1 in October 2023. The final results will be available in 2028. We plan to publish preliminary results after 2-3 years from the start of phase 1.

CONCLUSIONS

This study will be a step toward a better understanding of IPAF etiopathogenesis and outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/44802.

Animal models of silicosis: fishing for new therapeutic targets and treatments

Silicosis as an occupational lung disease has been present in our lives for centuries. Research studies have already developed and implemented many animal models to study the pathogenesis and molecular basis of the disease and enabled the search for treatments. As all experimental animal models used to date have their advantages and disadvantages, there is a continuous search for a better model, which will not only accelerate basic research, but also contribute to clinical aspects and drug development. We review here, for the first time, the main animal models developed to date to study silicosis and the unique advantages of the zebrafish model that make it an optimal complement to other models. Among the main advantages of zebrafish for modelling human diseases are its ease of husbandry, low maintenance cost, external fertilisation and development, its transparency from early life, and its amenability to chemical and genetic screening. We discuss the use of zebrafish as a model of silicosis, its similarities to other animal models and the characteristics of patients at molecular and clinical levels, and show the current state of the art of inflammatory and fibrotic zebrafish models that could be used in silicosis research.

Cellular Localization and Distribution of TGF-β1, GDNF and PDGF-BB in the Adult Primate Central Nervous System

The available data on the localization of transforming growth factor beta1 (TGF-β1), glial cell line-derived neurotrophic factor (GDNF), and platelet-derived growth factor-BB (PDGF-BB) in the adult primate and human central nervous system (CNS) are limited and lack comprehensive and systematic information. This study aimed to investigate the cellular localization and distribution of TGF-β1, GDNF, and PDGF-BB in the CNS of adult rhesus macaque (Macaca mulatta). Seven adult rhesus macaques were included in the study. The protein levels of TGF-β1, PDGF-BB, and GDNF in the cerebral cortex, cerebellum, hippocampus, and spinal cord were analyzed by western blotting. The expression and location of TGF-β1, PDGF-BB, and GDNF in the brain and spinal cord was examined by immunohistochemistry and immunofluorescence staining, respectively. The mRNA expression of TGF-β1, PDGF-BB, and GDNF was detected by in situ hybridization. The molecular weight of TGF-β1, PDGF-BB, and GDNF in the homogenate of spinal cord was 25 KDa, 30 KDa, and 34 KDa, respectively. Immunolabeling revealed GDNF was ubiquitously distributed in the cerebral cortex, hippocampal formation, basal nuclei, thalamus, hypothalamus, brainstem, cerebellum, and spinal cord. TGF-β1 was least distributed and found only in the medulla oblongata and spinal cord, and PDGF-BB expression was also limited and present only in the brainstem and spinal cord. Besides, TGF-β1, PDGF-BB, and GDNF were localized in the astrocytes and microglia of spinal cord and hippocampus, and their expression was mainly found in the cytoplasm and primary dendrites. The mRNA of TGF-β1, PDGF-BB, and GDNF was localized to neuronal subpopulations in the spinal cord and cerebellum. These findings suggest that TGF-β1, GDNF and PDGF-BB may be associated with neuronal survival, neural regeneration and functional recovery in the CNS of adult rhesus macaques, providing the potential insights into the development or refinement of therapies based on these factors.

HIF and ER stress are involved in TGFβ1-mediated wound closure of alveolar epithelial cells

Purpose: Alveolar epithelium dysfunction is associated with a very large spectrum of disease and an abnormal repair capacity of the airway epithelium has been proposed to explain the pathogenesis of Idiopathic Pulmonary Fibrosis (IPF). Following epithelium insult, the damaged cells will activate pathways implicated in the repair process, including proliferation and acquisition of migratory capacities to cover the denuded basement membrane. Induction of Endoplasmic Reticulum stress may be implicated in this process. Interestingly, ER stress excessive activation has been proposed as a central event associated with aberrant repair process and cellular dysfunction observed in IPF. Methods: We study by wound healing assay the molecular targets associated with Alveolar Epithelial Cells (AEC) repair. Results: We demonstrate that the wound recovery of AEC is associated with TGF-β1 signaling and increased transcriptional activity of ER stress and HIF-dependent genes. We further demonstrated that inhibition of TGF-β1 signaling, CHOP expression or HIF-1 expression, limits AECs wound closure. Conclusion: the use of pharmacological drugs targeting the ER/HIF-1 axis could be an attractive approach to limit AEC dysregulation in pathological condition, and confirmed a critical role of theses factor in response to alveolar injury.

Inhibition of Macrophage-Specific CHIT1 as an Approach to Treat Airway Remodeling in Severe Asthma

Chitotriosidase (CHIT1) is an enzyme produced by macrophages that regulates their differentiation and polarization. Lung macrophages have been implicated in asthma development; therefore, we asked whether pharmacological inhibition of macrophage-specific CHIT1 would have beneficial effects in asthma, as it has been shown previously in other lung disorders. CHIT1 expression was evaluated in the lung tissues of deceased individuals with severe, uncontrolled, steroid-naïve asthma. OATD-01, a chitinase inhibitor, was tested in a 7-week-long house dust mite (HDM) murine model of chronic asthma characterized by accumulation of CHIT1-expressing macrophages. CHIT1 is a dominant chitinase activated in fibrotic areas of the lungs of individuals with fatal asthma. OATD-01 given in a therapeutic treatment regimen inhibited both inflammatory and airway remodeling features of asthma in the HDM model. These changes were accompanied by a significant and dose-dependent decrease in chitinolytic activity in BAL fluid and plasma, confirming in vivo target engagement. Both IL-13 expression and TGFβ1 levels in BAL fluid were decreased and a significant reduction in subepithelial airway fibrosis and airway wall thickness was observed. These results suggest that pharmacological chitinase inhibition offers protection against the development of fibrotic airway remodeling in severe asthma.

Melatonin influences the biological characteristics of keloid fibroblasts through the Erk and Smad signalling pathways

Background

Keloids are abnormal fibrous hyperplasias that are difficult to treat. Melatonin can be used to inhibit the development of certain fibrotic diseases but has never been used to treat keloids. We aimed to discover the effects and mechanisms of melatonin in keloid fibroblasts (KFs).

Methods

Flow cytometry, CCK-8 assays, western blotting, wound-healing assays, transwell assays, collagen gel contraction assays and immunofluorescence assays were applied to demonstrate the effects and mechanisms of melatonin in fibroblasts derived from normal skin, hypertrophic scars and keloids. The therapeutic potential of the combination of melatonin and 5-fluorouracil (5-FU) was investigated in KFs.

Results

Melatonin significantly promoted cell apoptosis and inhibited cell proliferation, migration and invasion, contractile capability and collagen production in KFs. Further mechanistic studies demonstrated that melatonin could inhibit the cAMP/PKA/Erk and Smad pathways through the membrane receptor MT2 to alter the biological characteristics of KFs. Moreover, the combination of melatonin and 5-FU remarkably promoted cell apoptosis and inhibited cell migration and invasion, contractile capability and collagen production in KFs. Furthermore, 5-FU suppressed the phosphorylation of Akt, mTOR, Smad3 and Erk, and melatonin in combination with 5-FU markedly suppressed the activation of the Akt, Erk and Smad pathways.

Conclusions

Collectively, melatonin may inhibit the Erk and Smad pathways through the membrane receptor MT2 to alter the cell functions of KFs, while combination with 5-FU could exert even more inhibitory effects in KFs through simultaneous suppression of multiple signalling pathways.

Irisin attenuates angiotensin II-induced atrial fibrillation and atrial fibrosis via LOXL2 and TGFβ1/Smad2/3 signaling pathways

Objectives

Irisin was reported as a cardioprotective and anti-oxidative effector, while the effect on atrial fibrosis is unknown. The current research examined irisin's function in atrial fibrillation (AF); atrial fibrosis brought on by Ang II can be suppressed, thus lessening the risk of developing AF.

Materials and Methods

246 individuals were enrolled in the present case-control study. Chinese AF patients (n=126), 83 of whom were paroxysmal AF (PAF), 43 patients with persistent AF (PeAF), and 120 healthy controls. Saline or Ang II (2.0 mg/kg/day) was subcutaneously injected into healthy male C57BL/6 mice for four weeks. Once daily for four weeks, intraperitoneal injections of exogenous irisin (500 g/kg/day) were administered.

Results

In comparison to PAF patients and healthy controls (all P<0.05), PeAF patients had significantly higher rates of heart failure (HF), large left atrial size (LAD), hypertrophic protein B-type natriuretic peptide (BNP), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-terminal telopeptide of type I collagen (CTX-I), and transforming growth factor beta-1 (TGF-β1), while superoxide dismutase (SOD) level was low. Expression of irisin was decreased in AF patients' serum and Ang II-infused mice. Exogenous irisin dramatically reduced apoptosis, atrial fibrosis, atrial inflammation, and the susceptibility to AF caused by Ang II. In the atrial tissue, irisin inhibited Ang II-induced fibroblast transdifferentiation, LOXL2, TGF-β1, collagen production, and phosphorylation of Smad2/3.

Conclusion

The study results speculated that irisin could be a potential AF target, and it inhibited atrial fibrosis and significantly impaired increased AF susceptibility through inactivation of LOXL2 and the TGF-β/Smad pathway.

Th17 Cell-Derived Amphiregulin Promotes Colitis-Associated Intestinal Fibrosis Through Activation of mTOR and MEK in Intestinal Myofibroblasts

BACKGROUND & AIMS

Intestinal fibrosis is a significant complication of Crohn's disease (CD). Gut microbiota reactive Th17 cells are crucial in the pathogenesis of CD; however, how Th17 cells induce intestinal fibrosis is still not completely understood.

METHODS

In this study, T-cell transfer model with wild-type (WT) and Areg-/- Th17 cells and dextran sulfate sodium (DSS)-induced chronic colitis model in WT and Areg-/- mice were used. CD4+ T-cell expression of AREG was determined by quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of AREG on proliferation/migration/collagen expression in human intestinal myofibroblasts was determined. AREG expression was assessed in healthy controls and patients with CD with or without intestinal fibrosis.

RESULTS

Although Th1 and Th17 cells induced intestinal inflammation at similar levels when transferred into Tcrβxδ-/- mice, Th17 cells induced more severe intestinal fibrosis. Th17 cells expressed higher levels of AREG than Th1 cells. Areg-/- mice developed less severe intestinal fibrosis compared with WT mice on DSS insults. Transfer of Areg-/- Th17 cells induced less severe fibrosis in Tcrβxδ-/- mice compared with WT Th17 cells. Interleukin (IL)6 and IL21 promoted AREG expression in Th17 cells by activating Stat3. Stat3 inhibitor suppressed Th17-induced intestinal fibrosis. AREG promoted human intestinal myofibroblast proliferation, motility, and collagen I expression, which was mediated by activating mammalian target of rapamycin and MEK. AREG expression was increased in intestinal CD4+ T cells in fibrotic sites compared with nonfibrotic sites from patients with CD.

CONCLUSIONS

These findings reveal that Th17-derived AREG promotes intestinal fibrotic responses in experimental colitis and human patients with CD. Thereby, AREG might serve as a potential therapeutic target for fibrosis in CD.

Association of TNF-α, TGF-β1, amphiregulin, IL-2, and EGFR WITH pulmonary fibrosis in COVID-19

Pulmonary fibrosis is a well-recognized sequela associated with coronavirus disease 2019 (COVID-19), however the mechanism is yet to be clearly understood. The study was designed to evaluate the association of TNF-α, TGF- β1, amphiregulin, IL-2, and EGFR with pulmonary fibrosis after COVID-19 pneumonia. Non-severe, severe, and critical COVID-19 pneumonia patients were included in this study after the patients agreed and gave written informed consent. Blood samples were analyzed with the ELISA method for cytokine examination. The non-contrast chest CT scan was performed after patients were discharged from hospital. Seventy-nine patients with a mean age of 54 years (57 % men, 43 % women) were fully evaluated. Pulmonary fibrosis was found in 74 patients (93.7 %). Serum levels of TGF-β1 60.55 pg/mL (11.42-2001.16), TNF-α 13.31 pg/mL (3.54-200.32), EGFR 14.9 pg/mL(6.4-53.6), IL-2 12.41 pg/mL(11-14.13), amphiregulin 156.5 pg/mL (21.7-1234). Serum levels of TNF-α increase according to the severity of clinical classification. A significant association between serum levels of TGF-β1, TNF- α, and pulmonary fibrosis with rs-0.247, p = 0.027; rs 0.259, p = 0.046 was found. According to this study, TNF-α and TGF-β1 potentially participate in the process of pulmonary fibrosis in COVID-19.

Arecae pericarpium water extract alleviates chronic pancreatitis by deactivating pancreatic stellate cells

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas with irreversible morphological changes. Arecae pericarpium (ARP), known to improve gastrointestinal disorders, has not yet been reported to inhibit fibrosis in CP. Therefore, we investigated the beneficial effects of ARP on cerulein-induced CP. Cerulein (50 μg/kg) was administered intraperitoneally to mice every hour, six times a day, four times a week for a total of 3 weeks to induce CP. To ascertain the prophylactic effects of ARP, ARP water extract (50, 100, or 200 mg/kg) or saline was administered intraperitoneally 1 h before the onset of CP. To determine the therapeutic effects of ARP, ARP water extract (200 mg/kg) or saline was administered for a total of 1 week or 2 weeks, starting 2 weeks or 1 week after the onset of CP. The pancreas was collected immediately for histological analysis. Additionally, to determine the effectiveness and mechanism of ARP in alleviating pancreatic fibrosis, pancreatic stellate cells (PSCs) were isolated. ARP treatment considerably improved glandular atrophy and inflammation and repressed collagen deposition in the pancreas. Furthermore, ARP water extract inhibited extracellular matrix (ECM) constituents such as alpha-smooth muscle actin (α-SMA), collagen I, and fibronectin 1 (FN1) in pancreatic tissue and PSCs. ARP also suppressed transforming growth factor-β (TGF-β) signaling by inhibiting Smad2 phosphorylation. Our study suggests that ARP exhibits anti-fibrotic effects in cerulein-induced CP by inhibiting TGF-β/Smad signaling.

Ginkgolic acid improves bleomycin-induced pulmonary fibrosis by inhibiting SMAD4 SUMOylation

Idiopathic pulmonary fibrosis (IPF) is a refractory chronic respiratory disease with progressively exacerbating symptoms and a high mortality rate. There are currently only two effective drugs for IPF; thus, there is an urgent need to develop new therapeutics. Previous experiments have shown that ginkgolic acid (GA), as a SUMO-1 inhibitor, exerted an inhibitory effect on cardiac fibrosis induced by myocardial infarction. Regarding the pathogenesis of PF, previous studies have concluded that small ubiquitin-like modifier (SUMO) polypeptides bind multiple target proteins and participate in fibrosis of multiple organs, including PF. In this study, we found altered expression of SUMO family members in lung tissues from IPF patients. GA mediated the reduced expression of SUMO1/2/3 and the overexpression of SENP1 in a PF mouse model, which improved PF phenotypes. At the same time, the protective effect of GA on PF was also confirmed in the SENP1-KO transgenic mice model. Subsequent experiments showed that SUMOylation of SMAD4 was involved in PF. It was inhibited by TGF-β1, but GA could reverse the effects of TGF-β1. SENP1 also inhibited the SUMOylation of SMAD4 and then participated in epithelial-mesenchymal transition (EMT) downstream of TGF-β1. We also found that SENP1 regulation of SMAD4 SUMOylation affected reactive oxygen species (ROS) production during TGF-β1-induced EMT and that GA prevented this oxidative stress through SENP1. Therefore, GA may inhibit the SUMOylation of SMAD4 through SENP1 and participate in TGF-β1-mediated pulmonary EMT, all of which reduce the degree of PF. This study provided potential novel targets and a new alternative for the future clinical testing in PF.

The Effect of Ophiopogonin C in Ameliorating Radiation-Induced Pulmonary Fibrosis in C57BL/6 Mice: An Update Study

Background

The aim of this study was to assess and update the protective effects and underlying mechanisms of Ophiopogonin C (OP-C), a biologically active component separated and purified from Ophiopogon japonicus, in ameliorating radiation-induced pulmonary fibrosis in C57BL/6 mice administered thoracic radiation.

Methods and Materials

We randomly divided 75 mice into five groups and administered a dose of 12-Gy whole thoracic radiation to establish a pulmonary fibrosis animal model. Mice were treated with OP-C or dexamethasone combined with or without cephalexin by daily gavage for 4 weeks. All mice were sacrificed after the completion of thoracic irradiation at 28 weeks. Serum levels of interleukin-6 and transforming growth factor-β1 (TGF-β1) were evaluated. Moreover, superoxide dismutase (SOD) levels in lung tissue were measured. The severity of fibrosis was evaluated using the hydroxyproline content of the lung tissue. The pathological changes in the five groups were detected by hematoxylin and eosin and Masson trichrome staining. Smooth muscle actin expression was detected using immunohistochemical staining. Matrix metalloproteinases-2 (MMP-2) and tissue inhibitors of metalloproteases-2 (TIMP-2) were examined by immunohistochemical staining of the lung sections, and semiquantitative analysis was used to calculate the expression of MMP-2 and TIMP-2.

Results

Irradiated mice treated with OP-C or DXE combined with or without cephalexin significantly reduced mortality in mice and fibrosis levels by 1) reducing the deposition of collagen and accumulation of inflammatory cells and fibroblasts, 2) downgrading levels of the promote-fibrosis cytokine TGF-β1, and 3) increasing SOD activity in the lung tissue compared with that of irradiated mice without treatment. However, there were no statistical differences in fibrosis levels among the irradiated mice treated with OP-C or DXE combined with or without cephalexin.

Conclusion

OP-C significantly ameliorates radiation-induced pulmonary fibrosis and may be a promising therapeutic strategy for this disorder.

Blueberry Juice Attenuates Pulmonary Fibrosis via Blocking the TGF-β1/Smad Signaling Pathway

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal, and chronic lung disease, lacking a validated and effective therapy. Blueberry has demonstrated multiple pharmacological activities including anti-inflammatory, antioxidant, and anticancer. Therefore, the objective of this study was to investigate whether blueberry juice (BBJ) could ameliorate IPF. Experiments in vitro revealed that BBJ could significantly reduce the expressions of TGF-β1 modulated fibrotic protein, which were involved in the cascade of fibrosis in NIH/3T3 cells and human pulmonary fibroblasts. In addition, for rat primary lung fibroblasts (RPLFs), BBJ promoted the cell apoptosis along with reducing the expressions of α-SMA, vimentin, and collagen I, while increasing the E-cadherin level. Furthermore, BBJ could reverse epithelial–mesenchymal transition (EMT) phenotypic changes and inhibit cell migration, along with inducing the upregulation of E-cadherin in A549 cells. Compared with the vehicle group, BBJ treatment alleviated fibrotic pathological changes and collagen deposition in both bleomycin-induced prevention and treatment pulmonary fibrosis models. In fibrotic lung tissues, BBJ remarkably suppressed the expressions of collagen I, α-SMA, and vimentin and improved E-cadherin, which may be related to its inhibition of the TGF-β1/Smad pathway and anti-inflammation efficacy. Taken together, these findings comprehensively proved that BBJ could effectively prevent and attenuate idiopathic pulmonary fibrosis via suppressing EMT and the TGF-β1/Smad signaling pathway.

SAMiRNA Targeting Amphiregulin Alleviate Total-Body-Irradiation-Induced Renal Fibrosis

Fibrosis is a serious unintended side effect of radiation therapy. In this study, we aimed to investigate whether amphiregulin (AREG) plays a critical role in fibrosis development after total-body irradiation (TBI). We found that the expression of AREG and fibrotic markers, such as α-smooth muscle actin (α-SMA) and collagen type I alpha 1 (COL1α1), was elevated in the kidneys of 6 Gy TBI mice. Expression of AREG and α-SMA was mainly elevated in the proximal and distal tubules of the kidney in response to TBI, which was confirmed by immunofluorescence staining. Knockdown of Areg mRNA using self-assembled-micelle inhibitory RNA (SAMiRNA) significantly reduced the expression of fibrotic markers, including α-SMA and COL1α1, and inflammatory regulators. Finally, intravenous injections of SAMiRNA targeting mouse Areg mRNA (SAMiRNA-mAREG) diminished radiation-induced collagen accumulation in the renal cortex and medulla. Taken together, the results of the present study suggest that blocking of AREG signaling via SAMiRNA-mAREG treatment could be a promising therapeutic approach to alleviate radiation-induced kidney fibrosis.

Jiangtang Tongmai Prescription Reduced Diabetic Lung Injury Through SnoN and TGF-β1/Smads Signaling Pathway

By establishing a rat diabetes model in rats with intervening treatment by Jiangtang Tongmai Prescription (JTTMP), this study explored the restorative pairing effect of JTTMP on diabetic lung injury. The model of type II diabetes model was used to establish the rat diabetes model, using a high-fat diet and streptozotocin (STZ) induction. Different doses of JTTMP and metformin were administered as a therapeutic to intervene, and blood was collected to assess the blood glucose level of each group of rats. HE (Hematoxylin and eosin (H&E) staining was performed to detect the morphological changes in rat lung tissue and enzyme-linked immunoassay ELISA was used to detect and quantify the expression of interleukin (IL)-6, TNF tumor necrosis factor-ɑa, and IL-1β in serum and the lung tissue of each group of rats. The level expression of TGF-β1 [transforming growth factor (TGF)-β1), SnoN (transcriptional co-repressor Ski-N terminal (SnoN)], Smad2, Smad3, Smad7, and other signaling pathway proteins were assessed by Western blot. In comparison with the normal control (NC) group, rats in the diabetes model (DM) group lost weight and showed significantly increased blood sugar levels. The levels of TGF-β1 and Smad2/3 were increased in the DM group but Smad7 decreased. After 8 weeks of JTTMP intervention, the level of TGF-β1 and Smad2/3 decreased but Smad7 increased, blood sugar decreased significantly and the expression of inflammatory factors in lung tissue decreased. Therefore, JTTMP may activate SnoN and the downstream TGF-β1/Smads signaling pathway to repair diabetic lung injury, which suggests its application has potential for future clinical treatment of diabetes with lung injury.

Amphiregulin induces CCN2 and fibronectin expression by TGF-β through EGFR-dependent pathway in lung epithelial cells

BACKGROUND

Airway fibrosis is one of the pathological characteristics of severe asthma. Transforming growth factor (TGF)-β has been known to promote epithelial-mesenchymal transition formation and to play a role in the progression of tissue fibrosis. Cellular communication network factor 2 (CCN2) and fibronectin (FN) are well-known markers of EMT and fibrosis. However, whether AREG is involved in TGF-β-induced CCN2 and FN expression in human lung epithelial cells is unknown.

METHODS

AREG and FN were analyzed by immunofluorescence staining on ovalbumin-challenged mice. CCN2 and FN expression were evaluated in human lung epithelial (A459) cells following TGF or AREG treatment for the indicated times. Secreted AREG from A549 cells was detected by ELISA. Cell migration was observed by a wound healing assay. Chromatin immunoprecipitation was used to detect the c-Jun binding to the CCN2 promoter.

RESULTS

AREG and FN expression colocalized in lung tissues from mice with ovalbumin-induced asthma by immunofluorescence staining. Moreover, TGF-β caused the release of AREG from A549 cells into the medium. Smad3 siRNA down-regulated AREG expression. AREG also stimulated CCN2 and FN expression, JNK and c-Jun phosphorylation, and cell migration in A549 cells. AREG small interfering (si) RNA inhibited TGF-β-induced expression of CCN2, FN, and cell migration. Furthermore, AREG-induced CCN2 and FN expression were inhibited by EGFR siRNA, a JNK inhibitor (SP600125), and an activator protein-1 (AP-1) inhibitor (curcumin). EGFR siRNA attenuated AREG-induced JNK and c-Jun phosphorylation. Moreover, SP600125 downregulated AREG-induced c-Jun phosphorylation.

CONCLUSION

These results suggested that AREG mediates the TGF-β-induced EMT in human lung epithelial cells through EGFR/JNK/AP-1 activation. Understanding the role of AREG in the EMT could foster the development of therapeutic strategies for airway remodeling in severe asthma.

Herbal compounds in the treatment of pulmonary silicosis

Herbal compounds including those already well-established in traditional Chinese medicine have been increasingly tested in the treatment of various diseases. Recent studies have shown that herbal compounds can be of benefit also for pulmonary silicosis as they can diminish changes associated with silica-induced inflammation, fibrosis, and oxidative stress. Due to a lack of effective therapeutic strategies, development of novel approaches which may be introduced particularly in the early stage of the disease, is urgently needed. This review summarizes positive effects of several alternative plant-based drugs in the models of experimental silicosis with a potential for subsequent clinical investigation and use in future.

Herbal Compounds in the Treatment of Pulmonary Silicosis

Herbal compounds including those already well-established in traditional Chinese medicine have been increasingly tested in the treatment of various diseases. Recent studies have shown that herbal compounds can be of benefit also for pulmonary silicosis as they can diminish changes associated with silica-induced inflammation, fibrosis, and oxidative stress. Due to a lack of effective therapeutic strategies, development of novel approaches which may be introduced particularly in the early stage of the disease, is urgently needed. This review summarizes positive effects of several alternative plant-based drugs in the models of experimental silicosis with a potential for subsequent clinical investigation and use in future.

RS4651 suppresses lung fibroblast activation via the TGF-β1/SMAD signalling pathway

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive disease resulting in respiratory failure with no efficient treatment options. We investigated the protective effect of RS4651 on pulmonary fibrosis in mice and the mechanism.

METHODS

Intratracheal injection of bleomycin (BLM) was used to induce pulmonary fibrosis in mice. RS4561 was administered intraperitoneally at different doses. Histopathological changes were observed. The level of alpha-smooth muscle actin (α-SMA) were also tested. In vitro, the proliferation and migratory effects of RS4651 treatment on MRC-5 cells pre-treated with transforming growth factor (TGF-β1) were examined. RNA-sequencing was used to detect differentially expressed target genes. Then, the expression of α-SMA, pSMAD2 and SMAD7 were analysed during RS4651 treatment of MRC-5 cells with or without silencing by SMAD7 siRNA.

RESULTS

Histopathological staining results showed decreased collagen deposition in RS4651 administered mice. Additionally, a lower level of α-SMA was also observed compared to the BLM group. The results of in vitro studies confirmed that RS4651 can inhibit the proliferation and migration, as well as α-SMA and pSMAD2 expression in MRC-5 cells treated with TGF-β1. RNA-sequencing data identified the target gene SMAD7. We found that RS4651 could upregulate SMAD7 expression and inhibit the proliferation and migration of MRC-5 cells via SMAD7, and RS4651 inhibition of α-SMA and pSMAD2 expression was blocked in SMAD7-siRNA MRC-5 cells. In vivo studies further confirmed that RS4651 could upregulate SMAD7 expression in BLM-induced lung fibrosis in mice.

CONCLUSIONS

Our data suggest that RS4651 alleviates BLM-induced pulmonary fibrosis in mice by inhibiting the TGF-β1/SMAD signalling pathway.

Genotoxicity evaluation of self-assembled-micelle inhibitory RNA-targeting amphiregulin (SAMiRNA-AREG), a novel siRNA nanoparticle for the treatment of fibrotic disease

The self-assembled-micelle inhibitory RNA-targeting amphiregulin (SAMiRNA-AREG) is a novel small-interfering RNA (siRNA) nanoparticle that is used for treatment of pulmonary fibrosis. We investigated the potential genotoxicity of SAMiRNA-AREG based on the guidelines published by the Organization for Economic Cooperation and Development. In the bacterial reverse mutation assay (Ames test), SAMiRNA-AREG did not induce mutations in Salmonella typhimurium TA100, TA1535, TA98, and TA1537 and Escherichia coli WP2uvrA at concentrations of up to 3000 μg/plate with or without metabolic activation. The SAMiRNA-AREG (concentrations up to 500 μg/mL) did not induce chromosomal aberrations in cultured Chinese hamster lung cells with or without metabolic activation. In the in vivo mouse bone marrow micronucleus assay, the SAMiRNA-AREG (concentrations up to 300 mg/kg body weight) did not affect the proportions of polychromatic erythrocytes and total erythrocytes, nor did it increase the number of micronucleated polychromatic erythrocytes in ICR mice. Collectively, these results suggest that SAMiRNA-AREG is safe with regard to genotoxicity such as mutagenesis or clastogenesis under the present experimental conditions. These results might support the safety of SAMiRNA-AREG as a potential therapeutic agent for pharmaceutical development.

New Insights into Pathomechanisms and Treatment Possibilities for Lung Silicosis

Inhalation of silica particles is an environmental and occupational cause of silicosis, a type of pneumoconiosis. Development of the lung silicosis is a unique process in which the vicious cycle of ingestion of inhaled silica particles by alveolar macrophages and their release triggers inflammation, generation of nodular lesions, and irreversible fibrosis. The pathophysiology of silicosis is complex, and interactions between the pathomechanisms have not been completely understood. However, elucidation of silica-induced inflammation cascades and inflammation-fibrosis relations has uncovered several novel possibilities of therapeutic targeting. This article reviews new information on the pathophysiology of silicosis and points out several promising treatment approaches targeting silicosis-related pathways.

Targeted inhibition of β-catenin alleviates airway inflammation and remodeling in asthma via modulating the profibrotic and anti-inflammatory actions of transforming growth factor-β1

Background:

TGF-β₁ is a key cytokine involved in both airway inflammation and airway remodeling in asthma because of its anti-inflammatory and profibrotic effect. In our previous study, we found that knockdown of cytosolic β-catenin alleviated the profibrogenic effect of TGF-β₁ without influencing its anti-inflammatory effect. However, the exact role of targeting β-catenin in asthma is not yet fully demonstrated. In the present study, we investigated the effect and mechanism of targeting β-catenin in OVA-challenged asthmatic rats with airway inflammation and remodeling features.

Methods:

We integrated experimental asthma model and asthma related cell model to explore the effect of targeting β-catenin on airway inflammation and remodeling of asthma.

Results:

Blocking β-catenin with ICG001, a small molecule inhibitor of β-catenin/TCF via binding to cAMP-response elementbinding protein, attenuated airway inflammation by increasing levels of anti-inflammation cytokines IL-10, IL-35 and decreasing levels of T helper (Th)2 cells and Th17 cytokine. Suppressing β-catenin by ICG001 inhibited airway remodeling via reducing the level of TGF-β₁ and the expressions of Snail, MMP-7, MMP-9 and, up-regulating expression of E-cadherin, down-regulating expressions of α-SMA and Fn. Inhibition of β-catenin with ICG001 suppressed TGF-β₁ induced proliferation and activation of CCC-REPF-1, blocked TGF-β₁ induced epithelial–mesenchymal transition (EMT) of RLE-6TN.

Conclusion:

Blockade of β-catenin/TCF not only prevents TGF-β₁ induced EMT and profibrogenic effects involved in pathological remodeling of airway, but also alleviates airway inflammation in asthma by balancing pro-inflammatory and anti-inflammatory cytokine. In conclusion, targeting β-catenin specifically via inhibition of β-catenin/TCF might be a new therapeutic strategy for asthma.

The reviews of this paper are available via the supplemental material section.

In vivo silencing of amphiregulin by a novel effective Self-Assembled-Micelle inhibitory RNA ameliorates renal fibrosis via inhibition of EGFR signals

Amphiregulin (AREG) is a transmembrane glycoprotein recently implicated in kidney fibrosis. Previously, we reported that the AREG-targeting Self-Assembled-Micelle inhibitory RNA (SAMiRNA-AREG) alleviated fibrosis by stably silencing the AREG gene, and reduced the side effects of conventional siRNA treatment of pulmonary fibrosis. However, the therapeutic effect of SAMiRNA-AREG in renal fibrosis has not been studied until now. We used two animal models of renal fibrosis generated by a unilateral ureteral obstruction (UUO) and an adenine diet (AD) to investigate whether SAMiRNA-AREG inhibited renal fibrosis. To investigate the delivery of SAMiRNA-AREG to the kidney, Cy5-labeled SAMiRNA-AREG was injected into UUO- and AD-induced renal fibrosis models. In both kidney disease models, SAMiRNA-AREG was delivered primarily to the damaged kidney. We also confirmed the protective effect of SAMiRNA-AREG in renal fibrosis models. SAMiRNA-AREG markedly decreased the UUO- and AD-induced AREG mRNA expression. Furthermore, the mRNA expression of fibrosis markers, including α-smooth muscle actin, fibronectin, α1(I) collagen, and α1(III) collagen in the UUO and AD-induced kidneys, was diminished in the SAMiRNA-AREG-treated mice. The transcription of inflammatory markers (tumor necrosis factor-α and monocyte chemoattractant protein-1) and adhesion markers (vascular cell adhesion molecule 1 and intercellular adhesion molecule 1) was attenuated. The hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining results showed that SAMiRNA-AREG decreased renal fibrosis, AREG expression, and epidermal growth factor receptor (EGFR) phosphorylation in the UUO- and AD-induced models. Moreover, we studied the effects of SAMiRNA-AREG in response to TGF-β1 in mouse and human proximal tubule cells, and mouse fibroblasts. TGF-β1-induced extracellular matrix production and myofibroblast differentiation were attenuated by SAMiRNA-AREG. Finally, we confirmed that upregulated AREG in the UUO or AD models was mainly localized in the distal tubules. In conclusion, SAMiRNA-AREG represents a novel siRNA therapeutic for renal fibrosis by suppressing EGFR signals.

Salinomycin suppresses TGF-β1-induced EMT by down-regulating MMP-2 and MMP-9 via the AMPK/SIRT1 pathway in non-small cell lung cancer

Salinomycin (Sal) is a recently identified anti-tumor drug for treating several types of solid tumor; however, its effects on the migratory and invasive properties of non-small cell lung cancer (NSCLC) remain unclear. This study investigated the inhibitory effect underlying mechanisms of Salon transforming growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) and cell migration. Sal solidly blocked cell migration and invasion enhancement by TGF-β1-induced EMT, through recovering E-cadherin loss and suppressing mesenchymal markers induction, as well as TGF-β1-mediated AMPK/SIRT signaling activity upregulation. The pharmacologic inhibition or knockdown of AMPK or SIRT1 can act synergistically with Sal to inhibit TGF-β1-induced MMP-2 and MMP-9. In contrast, AMPK or SIRT1 upregulation can protect against TGF-β1-induced MMP-2 and MMP-9 inhibition by Sal. Next we demonstrated that the MMP-2 and MMP-9 knockdown can act synergistically with Sal to inhibit TGF-β1-induced EMT. Moreover, treatment of PMA of MMP activator increased TGF-β1-induced MMP-2 and MMP-9, even with Sal. Our results demonstrate that Sal suppresses TGF-β1-induced EMT by downregulating MMP-2 and MMP-9 through the AMPK/SIRT pathway, thereby inhibiting lung cancer cell migration and invasion.

Protective and anti-inflammatory effect of selenium nano-particles against bleomycin-induced pulmonary injury in male rats

Pulmonary fibrosis (PF) is an interstitial lung disease, in which the exact pathologic mechanisms are not fully understood. Drug trials for the treatment of PF have shown disappointing results and controversial. Recently, selenium nanoparticles (SeNPs) have received great attention for potential use in treatments, due to high bioactivity features and lower toxicity. This study evaluated the protective effect of SeNPs against pulmonary injury induced by bleomycin (single dose, 4 mg/kg, intratracheal) in male rats in early and late phases of the disease. The rats were treated with SeNPs by intraperitoneal injection (0.5 mg SeNP/kg) for five consecutive days in the early phase (a day after injection of bleomycin) and late phase (a week after injection of bleomycin). The results showed that injection of SeNPs in the early phase improved the degree of alveolitis and inflammation and lung structure damage. Also, led to significant decreases in density of transforming growth factor- β1 (TGF-β1) in the lung and tumor necrosis factor-α (TNF-α) levels in the serum and lung homogenates compared with bleomycin-administrated group. Notably, treatment with the SeNP during the late phase did not show any ameliorative effects. Thus, the data suggest that SeNP has a protective effect against bleomycin-induced pulmonary injury in rats in the early phase of the disease. This might mean that SeNPs may be a new therapeutic agent for the improvement of this disease in the early phases.

si-SNHG5-FOXF2 inhibits TGF-β1-induced fibrosis in human primary endometrial stromal cells by the Wnt/β-catenin signalling pathway

Background

Intrauterine adhesions (IUAs) are manifestations of endometrial fibrosis characterized by inflammation and fibrinogen aggregation in the extracellular matrix (ECM). The available therapeutic interventions for IUA are insufficiently effective in the clinical setting for postoperative adhesion recurrence and infertility problems. In this study, we investigated whether si-SNHG5-FOXF2 can serve as a molecular mechanism for the inhibition of IUA fibrosis ex vivo.

Methods

FOXF2, TGF-β1 and collagen expression levels were measured by microarray sequencing analysis in three normal endometrium groups and six IUA patients. We induced primary human endometrial stromal cells (HESCs) into myofibroblasts (MFs) to develop an IUA cell model with various concentrations of TGF-β1 at various times. Downstream target genes of FOXF2 were screened by chromatin immunoprecipitation combined with whole-genome high-throughput sequencing (ChIP-seq). We investigated ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs with FOXF2 downregulation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blotting (WB), immunohistochemistry (IHC), flow cytometry, ethylenediurea (EdU) and CCK8 assays. We identified long noncoding RNAs (lncRNA) SNHG5 as the upstream regulatory gene of FOXF2 through RNA immunoprecipitation (RIP), RNA pulldown and fluorescence in situ hybridization (FISH). Finally, we examined FOXF2 expression, ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs upon FOXF2 downregulation.

Results

FOXF2 was highly expressed in the endometrium of patients with IUA. Treatment of primary HESCs with 10 ng/ml TGF-β1 for 72 h was found to be most effective for developing an IUA cell model. FOXF2 regulated multiple downstream target genes, including collagen, vimentin (VIM) and cyclin D2/DK4, by ChIP-seq and ChIP-PCR. FOXF2 downregulation inhibited TGF-β1-mediated primary HESC fibrosis, including ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related protein expression. We identified lncRNA SNHG5 as an upstream gene that directly regulates FOXF2 by RIP-seq, qRT-PCR, WB and FISH. SNHG5 downregulation suppressed FOXF2 expression in the IUA cell model, resulting in synergistic repression of the Wnt/β-catenin pathway, thereby altering TGF-β1-mediated ECM aggregation in endometrial stromal cells ex vivo.

Conclusions

Regulation of the Wnt/β-catenin signalling pathway and ECM formation by si-SNHG5-FOXF2 effectively inhibited the profibrotic effect of TGF-β1 on primary HESCs. This finding can provide a molecular basis for antagonizing TGF-β1-mediated fibrosis in primary HESCs.

Amelioration of bleomycin-induced pulmonary fibrosis via TGF-β-induced Smad and non-Smad signaling pathways in galectin-9-deficient mice and fibroblast cells

Background

Galectin-9 is a β-galactoside-binding protein with two carbohydrate recognition domains. Recent studies have revealed that galectin-9 regulates cellular biological reactions and plays a pivotal role in fibrosis. The aim of this study was to determine the role of galectin-9 in the pathogenesis of bleomycin-induced systemic sclerosis (SSc).

Methods

Human galectin-9 levels in the serum of patients with SSc and mouse sera galectin-9 levels were measured by a Bio-Plex immunoassay and enzyme-linked immunosorbent assay. Lung fibrosis was induced using bleomycin in galectin-9 wild-type and knockout mice. The effects of galectin-9 on the fibrosis markers and signaling molecules in the mouse lung tissues and primary lung fibroblast cells were assessed with western blotting and quantitative polymerase chain reaction.

Results

Galectin-9 levels in the serum were significantly higher (9-fold) in patients compared to those of healthy individuals. Galectin-9 deficiency in mice prominently ameliorated epithelial proliferation, collagen I accumulation, and α-smooth muscle actin expression. In addition, the galectin-9 knockout mice showed reduced protein expression levels of fibrosis markers such as Smad2/3, connective tissue growth factor, and endothelin-1. Differences between the wild-type and knockout groups were also observed in the AKT, mitogen-activated protein kinase, and c-Jun N-terminal kinase signaling pathways. Galectin-9 deficiency decreased the signal activation induced by transforming growth factor-beta in mouse primary fibroblasts, which plays a critical role in fibroblast activation and aberrant catabolism of the extracellular matrix.

Conclusions

Our findings suggest that lack of galectin-9 protects against bleomycin-induced SSc. Moreover, galectin-9 might be involved in regulating the progression of fibrosis in multiple pathways.

Cellular senescence and EMT crosstalk in bleomycin-induced pathogenesis of pulmonary fibrosis-an in vitro analysis

With poor prognosis and aberrant lung remodeling, pulmonary fibrosis exhibits worldwide prevalence accompanied by an increase in burden in terms of hospitalization and death. Apart from genetic and non-genetic factors, fibrosis occurs as a side effect of bleomycin antineoplastic activity. Elucidating the cellular and molecular mechanism could help in the development of effective anti-fibrotic treatment strategies. In the present study, we investigated the underlying mechanism behind bleomycin-induced fibrosis using human alveolar epithelial cells (A549 cells). On the basis of the experimental observation, it was demonstrated that with transforming growth factor-β (TGF-β) as a central mediator of fibrosis progression, a cross-talk between epithelial-mesenchymal transition (EMT) and senescence upon bleomycin treatment occurs. This results in the advancement of this serious fibrotic condition. Fibrosis was initiated through integrin activation and imbalance in the redox state (NOX expression) of the cell. It progressed along the TGF-β-mediated non-canonical pathway (via ERK phosphorylation) followed by the upregulation of α-smooth muscle actin and collagen synthesis. Additionally, in this process, the loss of the epithelial marker E-cadherin was observed. Furthermore, the expressions of senescence markers, such as p21 and p53, were upregulated upon bleomycin treatment, thereby intensifying the fibrotic condition. Accordingly, the molecular pathway mediating the bleomycin-induced fibrosis was explored in the current study.

Protective effects of Rosavin on bleomycin-induced pulmonary fibrosis via suppressing fibrotic and inflammatory signaling pathways in mice

Idiopathic Pulmonary fibrosis (IPF) is diagnosed as a life-threatening, progressive and incurable lung disease characterized by accumulation of extracellular matrix and myofibroblasts, resulting in the function degradation and structural alterations in normal lung parenchyma. Notably, Pulmonary Fibrosis has been considering as a difficult problem in clinical with high mortality and effective treatment strategies. Rosavin, a benzylPropylene glycoside, is isolated from Rhodiola rosea L., exhibiting nootropic, anti-depressant, anti-cancer, anti-inflammatory and anti-oxidative activities. In this study, we attended to elucidate the pharmacological activity of Rosavin for treatment of pulmonary fibrosis induced by bleomycin in mice. The results indicated that Rosavin could significantly ameliorate the lung index and Pathological structure of mice with Pulmonary fibrosis by bleomycin-induced. Additionally, Rosavin could evidently decreased inflammatory cells infiltration in bronchoalveolar lavage fluid and pro-inflammatory cytokines expression in lung tissue specimens induced by bleomycin. Rosavin could down-regulate the expression of hydroxyproline and malondialdehyde and increased the activities of superoxide dismutase, glutathione peroxidase in lung tissue. The expression of Nrf2 were increased, and the expression of NF-κB p65, TGF-β1 and α-SMA were inhibited. The findings revealed the protective effects and the primary mechanism of rosavin on bleomycin-induced pulmonary fibrosis, which provided a scientific foundation for Rosavin as a promising candidate for Pulmonary fibrosis treatment.

Osthole decreases collagen I/III contents and their ratio in TGF-β1-overexpressed mouse cardiac fibroblasts through regulating the TGF-β/Smad signaling pathway

The present study was designed to elucidate whether the mechanism by which osthole decreases collagenI/III contents and their ratio is regulating the TGF-β/Smad signaling pathway in TGF-β1-overexpressed mouse cardiac fibroblasts (CFs). These CFs were cultured and treated with different concentrations of osthole. Our results showed that the TGF-β1 expression in the CFs transfected with that the recombinant expression plasmids pcDNA3.1(+)-TGF-β1 was significantly enhanced. After the CFs were treated with 1.25-5 μg·mL^-1 of osthole for 24 h, the mRNA and protein expression levels of collagensIand III were reduced. The collagen I/III ratio was also reduced. The mRNA and protein expression levels of TGF-β1, TβRI, Smad2/3, P-Smad2/3, Smad4, and α-SMA were decreased, whereas the expression level of Smad7 was increased. These effects suggested that osthole could inhibit collagen I and III expression and reduce their ratio via the TGF-β/Smad signaling pathway in TGF-β1 overexpressed CFs. These effects of osthole may play beneficial roles in the prevention and treatment of myocardial fibrosis.

lncRNAPCAT29 inhibits pulmonary fibrosis via the TGF‑β1‑regulated RASAL1/ERK1/2 signal pathway

Pulmonary fibrosis is a severe respiratory disease characterized by the aggregation of extracellular matrix components and inflammation‑associated injury. Studies have suggested that long non‑coding RNAs (lncRNA) may serve a role in the pathophysiological processes of pulmonary fibrosis. However, the potential molecular mechanisms involving the lncRNA, prostate cancer‑associated transcript 29 (lncRNAPCAT29) in the progression of pulmonary fibrosis are yet to be determined. In the present study, the role of lncRNAPCAT29 and the potential signaling mechanism in pulmonary fibrosis progression was investigated. Reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry revealed that the expression levels of lncRNAPCAT29 were downregulated within interstitial lung cells from mice with silica‑induced pulmonary fibrosis. Transfection with lncRNAPCAT29 was associated with upregulated expression of microRNA (miRNA)‑221 and downregulated expression of transforming growth factor‑β1 (TGF‑β1); reduced inflammation and fibrotic progression was also associated with lncRNAPCAT29 transfection. TGF‑β1 expression levels were inhibited within pulmonary fibroblasts due to lncRNAPCAT29 expression; NEDD4 binding protein 2 and Plexin‑A4 expression levels were also suppressed. Analysis of the potential mechanism underlying silica‑induced pulmonary fibrosis revealed that the expression levels of RAS protein activator like 1 (RASAL1) and extracellular signal‑regulated kinases 1/2 (ERK1/2) were suppressed due to lncRNAPCAT29 expression. The results of the present study demonstrated that lncRNAPCAT29 induced miRNA‑221 upregulation and TGF‑β1 downregulation. These observations were associated with reduced inflammation and progression of silica‑induced pulmonary fibrosis via the TGF‑β1‑regulated RASAL1/ERK1/2 signaling pathway, which may serve as a potential target for the treatment of pulmonary fibrosis.

Celecoxib and sulindac inhibit TGF-β1-induced epithelial-mesenchymal transition and suppress lung cancer migration and invasion via downregulation of sirtuin 1

The non-steroidal anti-inflammatory drugs (NSAIDs) celecoxib and sulindac have been reported to suppress lung cancer migration and invasion. The class III deacetylase sirtuin 1 (SIRT1) possesses both pro- and anticarcinogenic properties. However, its role in inhibition of lung cancer cell epithelial-mesenchymal transition (EMT) by NSAIDs is not clearly known. We attempted to investigate the potential use of NSAIDs as inhibitors of TGF-β1-induced EMT in A549 cells, and the underlying mechanisms of suppression of lung cancer migration and invasion by celecoxib and sulindac. We demonstrated that celecoxib and sulindac were effective in preventing TGF-β1-induced EMT, as indicated by upregulation of the epithelial marker, E-cadherin, and downregulation of mesenchymal markers and transcription factors. Moreover, celecoxib and sulindac could inhibit TGF-β1-enhanced migration and invasion of A549 cells. SIRT1 downregulation enhanced the reversal of TGF-β1-induced EMT by celecoxib or sulindac. In contrast, SIRT1 upregulation promoted TGF-β1-induced EMT. Taken together, these results indicate that celecoxib and sulindac can inhibit TGF-β1-induced EMT and suppress lung cancer cell migration and invasion via downregulation of SIRT1. Our findings implicate overexpressed SIRT1 as a potential therapeutic target to reverse TGF-β1-induced EMT and to prevent lung cancer cell migration and invasion.

Chimaphilin inhibits human osteosarcoma cell invasion and metastasis through suppressing the TGF-β1-induced epithelial-to-mesenchymal transition markers via PI-3K/Akt, ERK1/2, and Smad signaling pathways

Epithelial-to-mesenchymal transition is a cellular process associated with cancer invasion and metastasis. However, the antimetastatic effects of chimaphilin remain elusive. In this study, we attempted to investigate the potential use of chimaphilin as an inhibitor of TGF-β1-induced epithelial-to-mesenchymal transition in U2OS cells. We found that TGF-β1 induced epithelial-to-mesenchymal transition to promote U2OS cell invasion and metastasis. Western blotting demonstrated that chimaphilin inhibited U2OS cell invasion and migration, increased the expression of the epithelial phenotype marker E-cadherin, repressed the expression of the mesenchymal phenotype marker vimentin, as well as decreased the level of epithelial-to-mesenchymal-inducing transcription factors Snail1 and Slug during the initiation of TGF-β1-induced epithelial-to-mesenchymal transition. In this study, we revealed that chimaphilin up-regulated the E-cadherin expression level and inhibited the production of vimentin, Snail1, and Slug in TGF-β1-induced U2OS cells by blocking PI-3K/Akt and ERK 1/2 signaling pathway. Additionally, the TGF-β1-mediated phosphorylated levels of Smad2/3 were inhibited by chimaphilin pretreatment. Above all, we conclude that chimaphilin represents an effective inhibitor of the metastatic potential of U2OS cells through suppression of TGF-β1-induced epithelial-to-mesenchymal transition.

Upregulated miR-29c suppresses silica-induced lung fibrosis through the Wnt/β-catenin pathway in mice

Silicosis is an irreversible lung disease resulting from long-term inhalation of occupational dust containing silicon dioxide. However, the pathogenesis of silicosis has not been clearly understood yet. Accumulating evidence suggests that miR-29 may have a significant anti-fibrotic capacity, meanwhile it may relate to Wnt/β-catenin pathway. The purpose of this study was to discuss the role of miR-29 in the progression of silicosis. A lentiviral vector was constructed, named Lv-miR-29c, which was overexpressing miR-29c. In vivo, intratracheal treatment with Lv-miR-29c significantly increased expression of miR-29c, and reduced expression of β-catenin, matrix metalloproteinase (MMP)-2, and MMP-9 in the lung and levels of transforming growth factor-beta 1 (TGF-β1) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid, and notably attenuated pulmonary fibrosis as evidenced by hydroxyproline content in silica-administered mice. These results indicated that miR-29c inhibited the development of silica-induced lung fibrosis. Thus, miR-29c may be a candidate target for silicosis treatment via its regulation of the Wnt/β-catenin pathway.

Autophagy and the unfolded protein response promote profibrotic effects of TGF-β1 in human lung fibroblasts

Idiopathic pulmonary fibrosis (IPF) is a lethal fibrotic lung disease in adults with limited treatment options. Autophagy and the unfolded protein response (UPR), fundamental processes induced by cell stress, are dysregulated in lung fibroblasts and epithelial cells from humans with IPF. Human primary cultured lung parenchymal and airway fibroblasts from non-IPF and IPF donors were stimulated with transforming growth factor-β₁ (TGF-β₁) with or without inhibitors of autophagy or UPR (IRE1 inhibitor). Using immunoblotting, we monitored temporal changes in abundance of protein markers of autophagy (LC3βII and Atg5-12), UPR (BIP, IRE1α, and cleaved XBP1), and fibrosis (collagen 1α2 and fibronectin). Using fluorescent immunohistochemistry, we profiled autophagy (LC3βII) and UPR (BIP and XBP1) markers in human non-IPF and IPF lung tissue. TGF-β₁-induced collagen 1α2 and fibronectin protein production was significantly higher in IPF lung fibroblasts compared with lung and airway fibroblasts from non-IPF donors. TGF-β₁ induced the accumulation of LC3βII in parallel with collagen 1α2 and fibronectin, but autophagy marker content was significantly lower in lung fibroblasts from IPF subjects. TGF-β₁-induced collagen and fibronectin biosynthesis was significantly reduced by inhibiting autophagy flux in fibroblasts from the lungs of non-IPF and IPF donors. Conversely, only in lung fibroblasts from IPF donors did TGF-β₁ induce UPR markers. Treatment with an IRE1 inhibitor decreased TGF-β1-induced collagen 1α2 and fibronectin biosynthesis in IPF lung fibroblasts but not those from non-IPF donors. The IRE1 arm of the UPR response is uniquely induced by TGF-β₁ in lung fibroblasts from human IPF donors and is required for excessive biosynthesis of collagen and fibronectin in these cells.

The Processes and Mechanisms of Cardiac and Pulmonary Fibrosis

Fibrosis is the formation of fibrous connective tissue in response to injury. It is characterized by the accumulation of extracellular matrix components, particularly collagen, at the site of injury. Fibrosis is an adaptive response that is a vital component of wound healing and tissue repair. However, its continued activation is highly detrimental and a common final pathway of numerous disease states including cardiovascular and respiratory disease. Worldwide, fibrotic diseases cause over 800,000 deaths per year, accounting for ~45% of total deaths. With an aging population, the incidence of fibrotic disease and subsequently the number of fibrosis-related deaths will rise further. Although, fibrosis is a well-recognized cause of morbidity and mortality in a range of disease states, there are currently no viable therapies to reverse the effects of chronic fibrosis. Numerous predisposing factors contribute to the development of fibrosis. Biological aging in particular, interferes with repair of damaged tissue, accelerating the transition to pathological remodeling, rather than a process of resolution and regeneration. When fibrosis progresses in an uncontrolled manner, it results in the irreversible stiffening of the affected tissue, which can lead to organ malfunction and death. Further investigation into the mechanisms of fibrosis is necessary to elucidate novel, much needed, therapeutic targets. Fibrosis of the heart and lung make up a significant proportion of fibrosis-related deaths. It has long been established that the heart and lung are functionally and geographically linked when it comes to health and disease, and thus exploring the processes and mechanisms that contribute to fibrosis of each organ, the focus of this review, may help to highlight potential avenues of therapeutic investigation.

Microencapsulation of Lefty-secreting engineered cells for pulmonary fibrosis therapy in mice

Idiopathic pulmonary fibrosis (IPF) is a progressive disease that causes unremitting deposition of extracellular matrix proteins, thus resulting in distortion of the pulmonary architecture and impaired gas exchange. Associated with high morbidity and mortality, IPF is generally refractory to current pharmacological therapies. Lefty A, a potent inhibitor of transforming growth factor-β signaling, has been shown to have promising antifibrotic ability in vitro for the treatment of renal fibrosis and other potential organ fibroses. Here, we determined whether Lefty A can attenuate bleomycin (BLM)-induced pulmonary fibrosis in vivo based on a novel therapeutic strategy where human embryonic kidney 293 (HEK293) cells are genetically engineered with the Lefty A-associated GFP gene. The engineered HEK293 cells were encapsulated in alginate microcapsules and then subcutaneously implanted in ICR mice that had 1 wk earlier been intratracheally administered BLM to induce pulmonary fibrosis. The severity of fibrosis in lung tissue was assessed using pathological morphology and collagen expression to examine the effect of Lefty A released from the microencapsulated cells. The engineered HEK293 cells with Lefty A significantly reduced the expression of connective tissue growth factor and collagen type I mRNA, lessened the morphological fibrotic effects induced by BLM, and increased the expression of matrix metalloproteinase-9. This illustrates that engineered HEK293 cells with Lefty A can attenuate pulmonary fibrosis in vivo, thus providing a novel method to treat human pulmonary fibrotic disease and other organ fibroses.

Bacillus Calmette-Guerin alleviates airway inflammation and remodeling by preventing TGF-β1 induced epithelial-mesenchymal transition

Bacillus Calmette-Guerin (BCG) is a potent agent for the prevention of tuberculosis. Current studies have regarded BCG as an immunomodulator. However, there is little information on whether it can be used to inhibit airway inflammation and airway remodeling caused by asthma. Therefore, in this study, we investigate the role of epithelial-mesenchymal transition (EMT) in airway inflammation and airway remodeling as well as the possible therapeutic mechanism of BCG for the treatment of asthma. Wistar rats were sensitized and challenged by ovalbumin for 2 weeks or 8 weeks. BCG was subcutaneously administered daily before every ovalbumin challenge to determine its therapeutic effects. The 2 weeks model group showed extensive eosinophilia, chronic inflammatory responses, bronchial wall thickening, airway epithelium damage, increased levels of transforming growth factor β 1 (TGF-β₁) in both bronchoalveolar lavage fluid and sera, decreased expression of epithelial marker E-cadherin, and increased expressions of mesenchymal markers α-smooth muscle actin (α-SMA) and Fibronectin (Fn). Except for inflammatory responses, all responses were more significant in the 8 weeks model group which displayed characteristics of airway remodeling including subepithelial fibrosis, smooth muscle hypertrophy, and goblet cell hyperplasia. When compared with the model groups, BCG administration inhibited airway inflammation and airway remodeling, decreased TGF-β₁ levels, upregulated expression of E-cadherin, and downregulated expression of α-SMA and Fn. The present study suggests for the first time that increased secretion of TGF- β₁ induced by asthmatic chronic inflammation may result in EMT, which is one of the most important mechanisms of airway inflammation and airway remodeling seen with asthma. BCG alleviates airway inflammation and airway remodeling by preventing TGF-β₁ induced EMT, therefore BCG may be a new therapy for treating asthma.

Pirfenidone attenuates bleomycin-induced pulmonary fibrosis in mice by regulating Nrf2/Bach1 equilibrium

Background

Oxidative stress is one of the important factors involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF). The equilibrium of Nuclear factor-erythroid-related factor 2 (Nrf2)/[BTB (broad-complex, tramtrack and bric-a-brac) and CNC (cap‘n’collar protein) homology 1, Bach1] determines the expression level of antioxidant factors, further regulating the function of oxidation/antioxidation capacity. Pirfenidone (PFD) is one of two currently for IPF therapy approved drugs. PFD regulates intracellular antioxidants, inhibits secretion of inflammatory cytokines and collagen synthesis. However the mechanisms of its antioxidant effects remain elusive.

Methods

Effects of PFD treatment were studied in mouse lung fibroblasts (MLF) following induction by transforming-growth factor beta 1 (TGF-β1) and in mice following bleomycin-induced lung fibrosis. The mRNA and protein levels of oxidative stress-related factors Nrf2/Bach1 and their downstream antioxidant factors heme oxygenase-1 (Ho-1) and glutathione peroxidase 1 (Gpx1) were determined by RT-PCR and Western blot. Fibrosis-related cytokines interleukin-6 (IL-6) and myofibroblast markers type 1 collagen α1 (COL1A1) levels in supernate of MLF, serum, and bronchoalveolar lavage fluid (BALF) as well as malondialdehyde (MDA) in serum and BALF were detected by ELISA, reactive oxygen species (ROS) generation was measured by 2′,7′- dichlorofluorescin diacetate (DCFH-DA) assay and lung pathological/morphological alterations in mice were observed by HE and Masson to assess the antioxidant mechanism and therapeutic effects on pulmonary fibrosis induced by bleomycin.

Results

PFD inhibited Bach1 mRNA and protein expressions in mouse lung fibroblasts induced by TGF-β1 and lung tissues with pulmonary fibrosis induced by bleomycin. Furthermore, it improved Nrf2, Ho-1 and Gpx1 mRNA and protein expressions. After PFD treatment, COL1A1and IL-6 levels in supernate of MLF, serum, and BALF as well as ROS in lung tissues and MDA in serum and BALF from a mouse with pulmonary fibrosis were significantly decreased, and the infiltration of lung inflammatory cells and fibrosis degree were alleviated.

Conclusions

Theraputic effects of PFD for IPF were involved in Nrf2/Bach1 equilibrium which regulated the capacity of oxidative stress. The study provided new insights into the antioxidant mechanism of PFD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-017-0405-7) contains supplementary material, which is available to authorized users.

Bach1 siRNA attenuates bleomycin-induced pulmonary fibrosis by modulating oxidative stress in mice

Oxidative stress plays an essential role in inflammation and fibrosis. Bach1 is an important transcriptional repressor that acts by modulating oxidative stress and represents a potential target in the treatment of pulmonary fibrosis (PF). In this study, we knocked down Bach1 using adenovirus-mediated small interfering RNA (siRNA) to determine whether the use of Bach1 siRNA is an effective therapeutic strategy in mice with bleomycin (BLM)‑induced PF. Mouse lung fibroblasts (MLFs) were incubated with transforming growth factor (TGF)-β1 (5 ng/ml) and subsequently infected with recombined adenovirus-like Bach1 siRNA1 and Bach1 siRNA2, while an empty adenovirus vector was used as the negative control. The selected Bach1 siRNA with higher interference efficiency was used for the animal experiments. A mouse model of BLM-induced PF was established, and Bach1 siRNA (1x109 pfu) was administered to the mice via the tail vein. The results revealed that the Bach1 mRNA and protein levels were significantly downregulated by Bach1 siRNA. Furthermore, the MLFs infected with Bach1 siRNA exhibited increased mRNA and protein expression levels of heme oxygenase-1 and glutathione peroxidase 1, but decreased levels of TGF-β1 and interleukin-6 in the cell supernatants compared with the cells exposed to TGF-β1 alone. Bach1 knockdown by siRNA also enhanced the expression of antioxidant factors, but suppressed that of fibrosis‑related cytokines in mice compared with the BLM group. Finally, the inflammatory infiltration of alveolar and interstitial cells and the destruction of lung structure were significantly attenuated in the mide administered Bach1 siRNA compared with those in the BLM group. On the whole, our findings demonstrate that Bach1 siRNA exerts protective effects against BLM-induced PF in mice. Our data may provide the basis for the development of novel targeted therapeutic strategies for PF.

EFFECT OF TRIPTOLIDE ON PROLIFERATION AND APOPTOSIS OF ANGIOTENSIN II-INDUCED CARDIAC FIBROBLASTS IN VITRO: A PRELIMINARY STUDY

BACKGROUND

The effect of triptolide (TPL) on cardiac fibroblasts (CFbs) and cardiac fibrosis remain unknown till now. This study was conducted to explore the effects of TPL on proliferation and apoptosis of angiotensin II (Ang II)-induced CFbs.

MATERIALS AND METHODS

Ang II was used to promote proliferation of CFbs. Two dosages of TPL (10ng/ml and 100ng/ml) were chosen. MTT assay was used to detect cell survival rate in vitro. Flow cytometer was performed to analyze apoptosis of CFbs. Hydroxyproline concentration was detected with hydroxyproline assay kit. Quantitative real-time PCR was used to detect the expression of TGF-β1 and Smad3 mRNA.

RESULTS

Ang II promoted CFbs proliferation significantly. Compared to Ang II group, TPL markedly reduced the viability of CFbs and its Hydroxyproline concentration (P<0.05). Besides, TPL can significantly promote apoptosis of CFbs (P<0.05). Furthermore, TPL reduced the expressions of TGF-βΙ and Smad3 mRNA in Ang II-induced CFbs (P<0.05).

CONCLUSION

TPL can inhibit the proliferation of CFbs in rats by down-regulating TGF-β1/Smad3 signaling pathway. TPL might be a promising therapeutic drug for myocardial fibrosis.

Delivery of RNAi Therapeutics to the Airways-From Bench to Bedside

RNA interference (RNAi) is a potent and specific post-transcriptional gene silencing process. Since its discovery, tremendous efforts have been made to translate RNAi technology into therapeutic applications for the treatment of different human diseases including respiratory diseases, by manipulating the expression of disease-associated gene(s). Similar to other nucleic acid-based therapeutics, the major hurdle of RNAi therapy is delivery. Pulmonary delivery is a promising approach of delivering RNAi therapeutics directly to the airways for treating local conditions and minimizing systemic side effects. It is a non-invasive route of administration that is generally well accepted by patients. However, pulmonary drug delivery is a challenge as the lungs pose a series of anatomical, physiological and immunological barriers to drug delivery. Understanding these barriers is essential for the development an effective RNA delivery system. In this review, the different barriers to pulmonary drug delivery are introduced. The potential of RNAi molecules as new class of therapeutics, and the latest preclinical and clinical studies of using RNAi therapeutics in different respiratory conditions are discussed in details. We hope this review can provide some useful insights for moving inhaled RNAi therapeutics from bench to bedside.

Protective effects of ulinastatin and methylprednisolone against radiation-induced lung injury in mice

The effectiveness of ulinastatin and methylprednisolone in treating pathological changes in mice with radiation-induced lung injury (RILI) was evaluated. Forty C57BL/6 female mice received whole-chest radiation (1.5 Gy/min for 12 min) and were randomly allocated into Group R (single radiation, n = 10), Group U (ulinastatin treatment, n = 10), Group M (methylprednisolone treatment, n = 10), or Group UM (ulinastatin and methylprednisolone treatment, n = 10). Another 10 untreated mice served as controls (Group C). Pathological changes in lung tissue, pulmonary interstitial area density (PIAD) and expression levels of transforming growth factor β1 (TGF-β1) and tumor necrosis factor α (TNF-α) in lung tissue, serum and bronchoalveolar lavage fluid were determined. Alleviation of pathological changes in lung tissue was observed in Groups U, M and UM. Treatment with ulinastatin, methylprednisolone or both effectively delayed the development of fibrosis at 12 weeks after radiation. Ulinastatin, methylprednisolone or both could alleviate the radiation-induced increase in the PIAD (P < 0.05 or P < 0.01). Treatment with ulinastatin, methylprednisolone or both significantly reduced the expression of TNF-α, but not TGF-β1, at 9 weeks after radiation compared with Group R (P < 0.01). Ulinastatin and /: or methylprednisolone effectively decreased the level of TNF-α in lung tissue after RILI and inhibited both the inflammatory response and the development of fibrosis.

Metformin Reduces Bleomycin-induced Pulmonary Fibrosis in Mice

Metformin has anti-inflammatory and anti-fibrotic effects. We investigated whether metformin has an inhibitory effect on bleomycin (BLM)-induced pulmonary fibrosis in a murine model. A total of 62 mice were divided into 5 groups: control, metformin (100 mg/kg), BLM, and BLM with metformin (50 mg/kg or 100 mg/kg). Metformin was administered to the mice orally once a day from day 1. We sacrificed half of the mice on day 10 and collected the bronchoalveolar lavage fluid (BALF) from their left lungs. The remaining mice were sacrificed and analyzed on day 21. The right lungs were harvested for histological analyses. The messenger RNA (mRNA) levels of epithelial-mesenchymal transition markers were determined via analysis of the harvested lungs on day 21. The mice treated with BLM and metformin (50 mg/kg or 100 mg/kg) showed significantly lower levels of inflammatory cells in the BALF compared with the BLM-only mice on days 10 and 21. The histological examination revealed that the metformin treatment led to a greater reduction in inflammation than the treatment with BLM alone. The mRNA levels of collagen, collagen-1, procollagen, fibronectin, and transforming growth factor-β in the metformin-treated mice were lower than those in the BLM-only mice on day 21, although statistical significance was observed only in the case of procollagen due to the small number of live mice in the BLM-only group. Additionally, treatment with metformin reduced fibrosis to a greater extent than treatment with BLM alone. Metformin suppresses the inflammatory and fibrotic processes of BLM-induced pulmonary fibrosis in a murine model.