Therapy For Pulmonary Fibrosis Research Articles

Enhanced pulmonary uptake on 18F-FES-PET/CT scans after irradiation of the thoracic area: related to fibrosis?

RationaleThe use of 16α-[18F]fluoro-17β-estradiol (FES) positron emission tomography (PET) in clinical dilemmas and for therapy decision-making in lesions expressing estrogen receptors is growing. However, on a considerable number of FES PET scans, previously performed in a research and clinical setting in our institution, FES uptake was noticed in the lungs without an oncologic substrate. We hypothesized that this uptake was related to pulmonary fibrosis as a result of radiation therapy. This descriptive study therefore aimed to investigate whether radiation therapy in the thoracic area is possibly related to enhanced pulmonary, non-tumor FES uptake.MethodsAll FES-PET/CT scans performed in our institution from 2008 to 2017 were retrospectively analyzed. Scans from patients who had received irradiation in the thoracic area prior to the scan were compared to scans of patients who had never received irradiation in the thoracic area. The primary outcome was the presence of enhanced non-tumor FES uptake in the lungs, defined as visually increased FES uptake in the absence of an oncologic substrate on the concordant (contrast-enhanced) CT scan. All CT scans were evaluated for the presence of fibrosis or oncologic substrates.ResultsA total of 108 scans were analyzed: 70 scans of patients with previous irradiation in the thoracic area and 38 of patients without. Enhanced non-tumor FES uptake in the lungs was observed in 39/70 irradiated patients (56%), versus in 9/38 (24%) of non-irradiated patients. Fibrosis was present in 37 of the 48 patients with enhanced non-tumor FES uptake (77%), versus in 15 out of 60 (25%) patients without enhanced non-tumor uptake, irrespective of radiotherapy (p < 0.001).ConclusionAfter irradiation of the thorax, enhanced non-tumor uptake on FES-PET can be observed in the radiation field in a significant proportion of patients. This seems to be related to fibrosis. When observing enhanced FES uptake in the lungs, this should not be interpreted as metastases. Information on recent radiation therapy or history of pulmonary fibrosis should therefore be taken into consideration.

Rapamycin attenuates the paraquat‐induced pulmonary fibrosis through activating Nrf2 pathway

Oxidative stress is a key regulator of idiopathic pulmonary fibrosis. Paraquat (PQ)‐induced pulmonary fibrosis seriously endangers people's health. Rapamycin has been reported to alleviate PQ‐induced pulmonary fibrosis, but its underlying mechanism is unclear. The nuclear factor E2‐related factor 2 (Nrf2) plays an important regulatory role in the antioxidant therapy of PQ‐induced pulmonary fibrosis. In this study, we tried to confirm that rapamycin attenuates PQ‐induced pulmonary fibrosis by regulating Nrf2 pathway. In vivo, we proved that rapamycin could inhibit the degree of PQ‐induced oxidant stress as well as enhanced the expression of Nrf2. In vitro, rapamycin decreased the upregulated effects of cell death and apoptosis, fibrosis‐related factors expression and fibroblast‐to‐myofibroblast transformation by PQ treatment. In vivo, rapamycin treatment reduced fibrosis degree and the expression of fibrosis‐related factors in lung tissues of rat treated PQ. Furthermore, we also found that Nrf2 knockdown reduced the inhibitory effect of rapamycin on PQ‐induced pulmonary fibrosis, as well as decreased Nrf2 transfer from the cytoplasm into the nucleus. Our findings demonstrated that the protective effect of rapamycin is associated with the activation of the Nrf2 pathway in pulmonary fibrosis induced by PQ poisoning.

Inhibitory effects of pirfenidone on fibroblast to myofibroblast transition in rheumatoid arthritis-associated interstitial lung disease via the downregulation of activating transcription factor 3 (ATF3)

ObjectivePirfenidone (PFD) is an oral anti-fibrotic drug used for idiopathic pulmonary fibrosis (IPF) therapy. We determined the role of activating transcription factor 3 (ATF3) and the effect of PFD on fibroblast to myofibroblast transition (FMT) in rheumatoid arthritis-associated interstitial lung disease (RA-ILD). MethodsRA-ILD lung specimens were obtained by CT-guided percutaneous transthoracic biopsy. A pulmonary fibrosis mouse model was established by the intratracheal injection of bleomycin. Pathological variation and the expression of α-SMA and ATF3 were observed by H&E, Masson and immunofluorescence staining. Primary human lung fibroblasts (pHLFs) were isolated from lung tissues that were pathologically confirmed to be normal by pneumonectomy. Cell viability was detected using an MTT assay. Cell migration and invasion were detected using a Transwell chamber. The protein levels of α-SMA, ATF3, Smad3 and p-Smad3 were measured by Western blot. HLFs were infected with lentiviruses expressing ATF3 or scrambled shRNA. ResultsATF3 was dramatically upregulated in lung tissues from both bleomycin-induced mice and patients with RA-ILD compared with controls. The upregulation of ATF3 and the accumulation of collagen in the lung tissues of mice with pulmonary fibrosis were reduced by PFD. PFD significantly inhibited increases in the proliferation, invasion and migration of pHLFs stimulated by TGF-β1. Moreover, we observed the inhibitory effect of PFD on FMT via the downregulation of ATF3, which was further confirmed in ATF3 knockdown (KD) pHLFs. ConclusionsThis work shows the inhibitory effect of PFD on FMT in pHLFs, which is mediated by the downregulation of ATF3. Our findings suggest that PFD might have therapeutic potential for the treatment of RA-ILD.

Evaluation of Glutathione S-Transferase Inhibition Effects on Idiopathic Pulmonary Fibrosis Therapy with a Near-Infrared Fluorescent Probe in Cell and Mice Models.

Idiopathic pulmonary fibrosis (IPF) is a lung-limited and progressive fibrotic disease. The early diagnosis and therapies of IPF are still full of clinical challenges. Glutathione S-transferase (GSTs) plays significant roles in promoting the formation of pulmonary fibrosis. Herein, we report a fluorescent probe (Cy-GST) for the detection of GSTs concentration fluctuations in cells and in mice models. The probe can selectively and sensitively respond to GSTs with an "off-on" type fluorescence switch. Our results demonstrated that the level of intracellular GSTs increase in the pulmonary fibrosis cells and mice models. And the IPF patients hold high levels of GSTs concentrations. Thus, GSTs are likely to play important roles in pulmonary fibrosis. The inhibitor of GSTs TLK117 can reduce the severity of pulmonary fibrosis. The synergistic treatment of TLK117 and pirfenidone have better therapeutic effects than only using pirfenidone in pulmonary fibrosis mice models. The level of GSTs in IPF may be a new potential marker for IPF diagnosis. And the inhibition of GSTs may be a new therapeutic strategy for IPF treatment.

CircHIPK3 regulates lung fibroblast-to-myofibroblast transition by functioning as a competing endogenous RNA

Myofibroblasts predominantly emerging through fibroblast-to-myofibroblast transition (FMT) are considered to be the key collagen-producing cells in pulmonary fibrosis. Circular RNAs (circRNAs) are important players involved in many biological processes. circHIPK3 has been identified as the one of the most abundant circRNAs in human lung. In this study, we characterized the role of circHIPK3 in pulmonary fibrosis. We revealed that circHIPK3 is upregulated in bleomycin-induced pulmonary fibrosis mice model, FMT-derived myofibroblasts. circHIPK3 silencing can ameliorate FMT and suppress fibroblast proliferation in vivo and vitro. Fundamentally, circHIPK3 regulates FMT by functioning as an endogenous miR-338-3p sponge and inhibit miR-338-3p activity, thereby leading to increased SOX4 and COL1A1 expression. Moreover, dysregulated circHIPK3 expression was detected in the clinical samples of patients with idiopathic pulmonary fibrosis. Intervention of circHIPK3 may represent a promising therapy for pulmonary fibrosis.

Current and Future Idiopathic Pulmonary Fibrosis Therapy

The last years have led to advances in the therapeutic management of idiopathic pulmonary fibrosis (IPF), mainly through the discovery of new pathological pathways and drugs and better design of clinical trials. The objective of this review is both to describe the current therapies approved for the treatment of IPF and the emerging therapeutic approaches. Currently, nintedanib and pirfenidone are the basis of IPF therapy, based on the results of large randomized clinical trials showing their safety and efficacy in reducing disease progression. Nonetheless, the ideal IPF therapy is still lacking and trials are underway to test new therapeutic targets. The near future could bring to clinicians and patients a combined therapeutic strategy, hitting the disease from several simultaneous pathways and hopefully leading to clinical stabilization or improvement.

Molecular characterization of a precision-cut rat lung slice model for the evaluation of antifibrotic drugs.

The translation of novel pulmonary fibrosis therapies from preclinical models into the clinic represents a major challenge demonstrated by the high attrition rate of compounds that showed efficacy in preclinical models but demonstrated no significant beneficial effects in clinical trials. A precision-cut lung tissue slice (PCLS) contains all major cell types of the lung and preserves the original cell-cell and cell-matrix contacts. It represents a promising ex vivo model to study pulmonary fibrosis. In this study, using RNA sequencing, we demonstrated that transforming growth factor-β1 (TGFβ1) induced robust fibrotic responses in the rat PCLS model, as it changed the expression of genes functionally related to extracellular matrix remodeling, cell adhesion, epithelial-to-mesenchymal transition, and various immune responses. Nintedanib, pirfenidone, and sorafenib each reversed a subset of genes modulated by TGFβ1, and of those genes we identified 229 whose expression was reversed by all three drugs. These genes define a molecular signature characterizing many aspects of pulmonary fibrosis pathology and its attenuation in the rat PCLS fibrosis model. A panel of 12 genes and three secreted biomarkers, including procollagen I, hyaluronic acid, and WNT1-inducible signaling pathway protein 1 were validated as efficacy end points for the evaluation of antifibrotic activity of experimental compounds. Finally, we showed that blockade of αV-integrins suppressed TGFβ1-induced fibrotic responses in the rat PCLS fibrosis model. Overall, our results suggest that the TGFβ1-induced rat PCLS fibrosis model may represent a valuable system for target validation and to determine the efficacy of experimental compounds.

Lung transplant candidates with idiopathic pulmonary fibrosis and long-term pirfenidone therapy: Treatment feasibility influences waitlist survival.

Idiopathic pulmonary fibrosis (IPF) is a chronically progressive lung disease with exceptionally poor prognosis. While lung transplantation (LTx) is considered the last-resort therapeutic option, dismal waitlist mortality still hampers the salvage of patients with IPF. Pirfenidone, originally designed for IPF treatment, has increasingly been utilized. This study aimed to evaluate whether Pirfenidone could influence outcomes of patients with IPF on the Japanese LTx waitlist. This retrospective single-center cohort study included 25 consecutive patients with IPF who were registered as LTx candidates at our institution between July 1999 and August 2016. Patients with a history of pretransplant Pirfenidone therapy (Pirfenidone group) were compared with those with no history (non-Pirfenidone group). In total, 6 (24%) patients received Pirfenidone as pretransplant therapy for 45.2 (range, 18.6-66.8) months. During the treatment period, the Pirfenidone group achieved a significant reduction in the decline rate of the forced vital capacity (-6.2% vs. -0.3%, p = 0.04) and a lower lung allocation score (31 vs. 41, p = 0.013) compared with the non-Pirfenidone group. The Pirfenidone group exhibited 100% waitlist survival three years after registration that was comparable to other indications, and 66% of the patients were still alive at the time of organ availability. No patient in the Pirfenidone group developed Pirfenidone-related surgical complications postoperatively. Patients with IPF successfully managed with long-term Pirfenidone therapy achieved favorable outcomes after LTx registration, comparable to other patients with LTx indications. The tolerability to antifibrotic therapy can be a predictor of waitlist survival.

Neutralization of IL-18 by IL-18 binding protein ameliorates bleomycin-induced pulmonary fibrosis via inhibition of epithelial-mesenchymal transition

Idiopathic pulmonary fibrosis (IPF) is a fatal parenchymal lung disease with limited effective therapies. Interleukin (IL)-18 belongs to a rather large IL-1 gene family and is a proinflammatory cytokine, which acts in both acquired and innate immunity. We have previously reported that IL-18 play an important role in lipopolysaccharide-induced acute lung injury in mice. Persistent inflammation often drives fibrotic progression in the bleomycin (BLM) injury model. However, the role of IL-18 in pulmonary fibrosis (PF) is still unknown. IL-18 binding protein (IL-18BP) is able to neutralize IL-18 biological activity and has a protective effect against renal fibrosis. The aim of this study was to investigate the effects of IL-18BP on BLM-induced PF. In the present study, we found that IL-18 was upregulated in lungs of BLM-injured mice. Neutralization of IL-18 by IL-18BP improved the survival rate and ameliorated BLM-induced PF in mice, which was associated with attenuated pathological changes, reduced collagen deposition, and decreased content of transforming growth factor-β1 (TGF-β1). We further demonstrated that IL-18BP treatment suppressed the BLM-induced epithelial mesenchymal transition (EMT), characterized by decreased α-smooth muscle actin (α-SMA) and increased E-cadherin (E-cad) in vivo. In addition, we provided in vitro evidence demonstrating that IL-18 promoted EMT through upregulation of Snail-1 in A549 cells. In conclusion, our findings raise the possibility that the increase of IL-18 is involved in the development of BLM-induced PF through modulating EMT in a Snail-1-dependent manner. IL-18BP may be a worthwhile candidate option for PF therapy.

SUCCESSFUL TRANSPLANTATION DEFIES GENETICS: A CASE OF RAPIDLY-PROGRESSIVE PULMONARY FIBROSIS DUE TO HERMANSKY-PUDLAK SYNDROME

SESSION TITLE: Pulmonary Manifestations of Systemic Disease SESSION TYPE: Fellow Case Reports PRESENTED ON: 10/08/2018 11:00 AM - 12:00 PM INTRODUCTION: Hermansky-Pudlak syndrome (HPS) is an extremely rare autosomal-recessive condition that devastates young victims with highly penetrant pulmonary fibrosis. We present a case of a middle-aged woman with clinically characteristic HPS and severe respiratory failure due to interstitial destruction, who was successfully cured with the first bilateral lung transplantation done at this institution. CASE PRESENTATION: Our patient is a 47-year old Puerto-Rican female, never-smoker, who was referred for lung transplant evaluation in the setting of quickly progressing and functionally limiting fibrosis. A previously healthy woman with a medical history solely of menorrhagia and occasional heavy bleeding with dental work, presented to us as a very ill and dyspneic patient. Over the course of one year, a bothersome cough turned into debilitating exertional fatigue and air-hunger, significant hypoxia requiring supplemental oxygen, marked weight reduction, and a loss of independence. Her presenting physical exam was notable for horizontal saccades, pale skin coloring, and coarse diffuse rales. Radiographic findings and open lung biopsy proved significant pulmonary fibrosis, which in addition to her ethnic background and the clinical history suggested HPS. This was ultimately confirmed with gene testing and platelet electron microscopic analysis.After thorough discussion and formal evaluation, the patient was listed for and successfully underwent bilateral lung transplantation, complicated only by (as expected) moderate bleeding. Her respiratory symptoms completely resolved, and she resumed her usual activities, oxygen-free. DISCUSSION: In a small section of Northwest Puerto-Rico, 1 in 21 persons carries the mutation for HPS, subjecting roughly 1 in 1800 to the above syndrome. Diagnostic criteria include 1) tyrosine positive oculocutaneous albinism (OCA); and 2) a bleeding disorder due to platelet dysfunction. HPS gene products are ubiquitously expressed and highly important in lysosome trafficking, which is thought to be causative of pulmonary fibrosis. Patients with HPS subtype-1 universally develop lung fibrosis, often in the 3rd or 4th decade of life. Radiographic findings include increased reticular opacities, thickened intralobular septa, traction bronchiectasis, and honeycombing, with a heterogenic course of lung function decline across patients. There are no known therapies for HPS-related pulmonary fibrosis, but as in this case, there are several cases of successful transplantation despite a bleeding risk. CONCLUSIONS: HPS is a rare but recognizable cause of interstitial lung disease. Clinical and epidemiologic factors should prompt appropriate diagnostic work-up and early referral for transplantation. There are several ongoing clinical trials to further define molecular characteristics of HPS, which holds great promise to expand our limited understanding of pulmonary fibrosis. Reference #1: El-Chemaly, S. and Young L. "Hermansky-Pudlak Syndrome.” Clin Chest Med, 2016; 37 (3) 505-511. Reference #2: Vicary G, et al. "Pulmonary Fibrosis in Hermansky-Pudlak Syndrome.” Ann Am Thorac Soc, 2016; 13 (10) 1839-1846. DISCLOSURES: Chief Medical Officer relationship with BiO2 Medical Please note: >$100000 Added 03/01/2018 by Luis Angel, source=Web Response, value=Intellectual Property No relevant relationships by Jessica Riggs, source=Web Response

A Chinese Traditional Therapy for Bleomycin-Induced Pulmonary Fibrosis in Mice.

Pulmonary fibrosis is a chronic and fatal disease of lung tissue with high incidence and mortality in the world. The exploration of effective treatment for pulmonary fibrosis remains an urgent challenge. In our study, Qingfei Xieding was investigated as a novel Chinese traditional patent medicine against pulmonary fibrosis. A pulmonary fibrosis mouse model was constructed by injecting with bleomycin sulfate. Following Qingfei Xieding administration, lung samples were collected to assess pulmonary phenotype changes by analyzing lung coefficient, wet/dry, and histopathologic section. Levels of nitric oxide (NO), hydroxyproline (HYP), malondialdehyde (MDA), and total antioxidant capacity were measured to evaluate the degree of oxidation. A single-cell gel electrophoresis (SCGE) assay was used to evaluate bleomycin-induced DNA damage. Western blotting and real-time quantitative PCR were performed to determine the abundance of inducible nitric oxide synthase (iNOS), connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA), and fibronectin (FN). In the present study, Qingfei Xieding administration significantly attenuated bleomycin-induced pulmonary fibrosis in mice by reducing lung coefficient, wet/dry, NO, HYP, and MDA as well as the expression of iNOS, CTGF, α-SMA, FN, and DNA damage. The results indicated that Qingfei Xieding is effective to resist oxidative damage and histopathologic lesion, serving a protection role on bleomycin-induced pulmonary fibrosis.

Parthenolide attenuated bleomycin-induced pulmonary fibrosis via the NF-\u03baB/Snail signaling pathway

BackgroundParthenolide (PTL) is a natural molecule isolated from Tanacetum parthenium that exhibits excellent anti-inflammatory and antitumor activities. Pulmonary fibrosis (PF), especially idiopathic pulmonary fibrosis (IPF), is a chronic lung disease that lacks a proven effective therapy. The present study evaluated the therapeutic effect of PTL on PF.MethodsSerum-starved primary lung fibroblasts and HFL1 cells were treated with different doses of PTL, and cell viability and the migration rate were measured. Western blot analysis and a dual-luciferase assay were used to analyze the epithelial–mesenchymal transition (EMT)-related transcription factors influenced by PTL treatment in A549 cells and primary lung epithelial cells. Mice with bleomycin (BLM)-induced pulmonary fibrosis were treated with different doses of intragastric PTL, and pathological changes were evaluated using Hematoxylin-eosin (H&E) staining and immunohistochemical analysis.ResultsOur results demonstrated that PTL reduced the cell viability and migration rate of lung fibroblasts and inhibited the expression of EMT-related transcription factors in lung epithelial cells. In vivo studies demonstrated that PTL attenuated BLM-induced pulmonary fibrosis and improved the body weight and pathological changes of BLM-treated mice. We further demonstrated that PTL attenuated BLM-induced PF primarily via inhibition of the NF-κB/Snail signaling pathway.ConclusionThese findings suggest that PTL inhibits EMT and attenuates BLM-induced PF via the NF-κB/Snail signaling pathway. PTL is a worthwhile candidate compound for pulmonary fibrosis therapy.

The hedgehog and Wnt/\u03b2-catenin system machinery mediate myofibroblast differentiation of LR-MSCs in pulmonary fibrogenesis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal lung disease that is characterized by enhanced changes in stem cell differentiation and fibroblast proliferation. Resident mesenchymal stem cells (LR-MSCs) can undergo phenotype conversion to myofibroblasts to augment extracellular matrix production, impairing function and contributing to pulmonary fibrosis. Hedgehog and Wnt signaling are developmental signal cascades that play an essential role in regulating embryogenesis and tissue homeostasis. Recently, it has been reported that both hedgehog and Wnt signaling play important roles in pulmonary fibrogenesis. Thus, the identification of specific target regulators may yield new strategy for pulmonary fibrosis therapies. In our work, we demonstrated the critical role of Gli1, Wnt7b, Wnt10a and Fzd10 in the process of pulmonary fibrogenesis in vitro and in vivo. Gli1 was induced in LR-MSCs following TGF-β1 treatment and fibrotic lung tissues. Inhibition of Gli1 suppressed myofibroblast differentiation of LR-MSCs and pulmonary fibrosis, and decreased the expression of Wnt7b, Wnt10a and β-catenin. Gli1 bound to and increased promoter activity of the Wnt7b and Wnt10a genes, and Wnt7b and Wnt10a were critical activators of Wnt/β-catenin signaling. It was noteworthy that Fzd10 knockdown reduced Wnt7b and Wnt10a-induced activation of Wnt/β-catenin signaling, which imply that Wnt7b and Wnt10a may be the ligands for Fzd10. Moreover, siRNA-mediated inhibition of Fzd10 prevented TGF-β1-induced myofibroblast differentiation of LR-MSCs in vitro and impaired bleomycin-induced pulmonary fibrosis. We conclude that hedgehog and Wnt/β-catenin signaling play a critical role in promoting myofibroblast differentiation of LR-MSCs and development of pulmonary fibrosis. These findings elucidate a therapeutic approach to attenuate pulmonary fibrosis through targeted inhibition of Gli1 or Fzd10.

Effect of CoCl2 or H2O2 pre-conditioned mesenchymal stem cells in a mouse model of pulmonary fibrosis

Introduction: Pulmonary Fibrosis is characterized by excessive matrix deposition which leads to airway remodeling and disruption of the typical architecture of the lung parenchyma. The disease progression is associated with a high mortality rate. The current treatment for pulmonary fibrosis includes drugs which either reduce progression of the disease or provide symptomatic relief. Multiple studies have examined the effect of cell-based therapy in pulmonary fibrosis. We investigated the effect of administration of pre-conditioned bone marrow-derived mesenchymal stem cells (BMMSC) in a mouse model of pulmonary fibrosis.&#x0D; Methods: Firstly, we examined the effect of pre-conditioning on the cells using cell-based assays. We found that pre-conditioning did not significantly alter cell proliferation or led to cellular inflammation. The cells continued to express MSC marker, CD105, and pluripotency marker Oct3/4. Next, we evaluated the proliferative and anti-inflammatory potential of BMMSC administration using a series of assays in a mouse model of pulmonary fibrosis. Bleomycin was administered to induce pulmonary fibrosis in mice on Day 0. MSCs were administered on day 1 and day 3; the mice were sacrificed on day 22, and their tissues were collected for analysis.&#x0D; Results: We found that similar to untreated cells, administration of pre-conditioned cells resulted in an increase in the proliferative potential and reduction in inflammation in the lung tissue, bronchoalveolar lavage, bone marrow, and blood. We observed reduction in the number of granulocytes in peripheral blood upon MSC administration. However, we did not observe any structural changes in the lung upon MSC administration. We found a small reduction in collagen content in the lung which was also seen upon staining with Masson's trichrome.&#x0D; Conclusion: These results demonstrate that pre-conditioned BM-MSC lead to improvement in the disease state through paracrine effects but pre-conditioning of cells for 24 hours does not significantly improve the beneficial effect of MSC administration.

Inhalable gadofullerenol/[70] fullerenol as high-efficiency ROS scavengers for pulmonary fibrosis therapy

Pulmonary fibrosis has become a fatal disease for its high incidence and few effective drugs available in clinic. In this study, gadofullerenol (GF-OH) and [70] fullerenol (C70-OH) nanoparticles (NPs) prepared by a one-pot reaction were designed as nanomedicines to treat this fatal disease. It was revealed that the inhalation of gadofullerenols and [70] fullerenols substantially alleviates the collagen deposition induced by acute lung injury. Based on detailed studies of oxidative stress parameters and transforming growth factor-β1 (TGF-β1), we demonstrated they owned the antioxidant and anti-inflammatory functions for the modulation of ROS-mediated inflammation process. Thus the therapeutic effect may be associated with synergistic mechanism of scavenging free radicals and indirectly modulating TGF-β1 expression. Moreover, GF-OH NPs were observed to show the superiority to C70-OH NPs both in vitro and in vivo due to the structural distinction. These results suggest the inhalable fullerenols are highly potential for clinical therapy of pulmonary fibrosis.

Diterpene ginkgolides meglumine injection protects against paraquat-induced lung injury and pulmonary fibrosis in rats

In this study, we aimed to investigate the effects of diterpene ginkgolides meglumine injection (DGMI) on paraquat (PQ)-induced lung injury and pulmonary fibrosis in rats. Male SD rats were challenged by PQ (20 mg/kg, i.p.) with or without either DGMI (1.25, 2.5, 5 mg/kg, i.p.) or Edaravone (EDA, 6 mg/kg, i.p.) posttreatment 2 h after PQ administration. Lung tissues were removed for biochemical analyses and pathological examinations on day 1, day 3, day 7, day 14 and day 21. Results showed that the administration of DGMI significantly increased the survival of PQ-challenged rats. At the same time, DGMI reversed the increase of Malondialdehyde (MDA) level and the decrease of Super Oxide Dismutase (SOD) level in lung tissues. Moreover, lung to body weight ratio, Interleukin-1beta (IL-1β), Interleukin-6 (IL-6) and Tumor necrosis factor-alpha (TNF-α) levels in lung tissues were reduced compared with the model group. H&E and Masson staining revealed that DGMI (5 mg/kg) alleviated histological injury and pulmonary fibrosis, and EDA (6 mg/kg) exerted approximate effects. Immunohistochemistry staining presented that the benefit effects of DGMI were associated with its ability to activate Akt-Nrf-2 pathway. In conclusion, these results suggest that DGMI possesses potential role in future therapies for PQ-induced lung injury and pulmonary fibrosis.

Thyroid hormone inhibits lung fibrosis in mice by improving epithelial mitochondrial function.

Thyroid hormone (TH) is critical for the maintenance of cellular homeostasis during stress responses, but its role in lung fibrosis is unknown. Here, we found that the activity and expression of iodothyronine deiodinase 2 (DIO2), an enzyme that activates TH, was higher in lungs of patients with idiopathic pulmonary fibrosis compared to control individuals and correlated with disease severity. We also found that Dio2 knockout mice exhibited enhanced bleomycin-induced lung fibrosis. Aerosolized TH delivery increased survival and resolved fibrosis in two models of pulmonary fibrosis in mice (intratracheal bleomycin and inducible TGF-β1). Sobetirome, a TH mimetic, also blunted bleomycin-induced lung fibrosis. Given after bleomycin-induced injury, TH promoted mitochondrial biogenesis, improved mitochondrial bioenergetics and attenuated mitochondria-regulated apoptosis in alveolar epithelial cells both in vivo and in vitro. TH did not blunt fibrosis in Ppargc1a or Pink1 knockout mice suggesting dependence on these pathways. We conclude that the TH anti-fibrotic properties are associated with protection of alveolar epithelial cells and restoration of mitochondrial function and thus may represent an effective therapy for pulmonary fibrosis.

Treatment of pulmonary fibrosis with siRNA against a collagen-specific chaperone HSP47 in vitamin A-coupled liposomes

ABSTRACTBackground: Pulmonary fibrosis is a life-threatening pathological state of progressive interstitial lung diseases, such as idiopathic pulmonary fibrosis. Myofibroblasts are known to play a critical role in the pathogenesis of pulmonary fibrosis. This study aimed to evaluate the inhibitory effect of a small interfering RNA (siRNA) on a collagen-specific chaperone heat shock protein 47 (HSP47). The siRNA was preferentially delivered to myofibroblasts in a bleomycin (BLM)-induced pulmonary fibrosis rat model using siRNA against HSP47, encapsulated in a vitamin A-coupled liposome (VA-lip-siRNA HSP47). Methods and Results: Male Sprague–Dawley rats were treated with an intratracheal injection of BLM or phosphate buffered saline followed by an intravenous injection of VA-lip-siRNA HSP47 three times per week under preventive administration schedules from day 1 to day 21 and therapeutic administration schedules from day 15 to day 35. The expression of HSP47 after the treatment was assessed by immunoblotting. The specific delivery of VA-lip-siRNA HSP47 conjugated with 6′-carboxyfluoresce into myofibroblasts was examined by immunofluorescence staining. The effect of VA-lip-siRNA HSP47 on fibrosis was analyzed by morphological and biochemical methods. Preferential delivery of VA-lip-siRNA HSP47 to myofibroblasts in fibrotic areas in BLM-treated rats was verified by immunofluorescence staining. Treatment of VA-lip-siRNA HSP47 clearly suppressed HSP47 expression and induced apoptosis of myofibroblasts in the lung of BLM-treated rats. Hydroxyproline levels and inflammatory cytokines in the lungs, and the number of inflammatory cells in the bronchial alveolar lavage of BLM-treated rats were significantly suppressed by the treatment. Morphological assessment showed that VA-lip-siRNA HSP47 also significantly improved the morphological pulmonary fibrosis of BLM-treated rats in both preventive and therapeutic schedules. Conclusions: These results suggest that VA-lip-siRNA HSP47 improves pulmonary fibrosis in not only preventive, but also therapeutic schedules, and thus, this drug delivery system should provide a novel therapy for refractory pulmonary fibrosis.

An Official American Thoracic Society Workshop Report: Use of Animal Models for the Preclinical Assessment of Potential Therapies for Pulmonary Fibrosis.

Numerous compounds have shown efficacy in limiting development of pulmonary fibrosis using animal models, yet few of these compounds have replicated these beneficial effects in clinical trials. Given the challenges associated with performing clinical trials in patients with idiopathic pulmonary fibrosis (IPF), it is imperative that preclinical data packages be robust in their analyses and interpretations to have the best chance of selecting promising drug candidates to advance to clinical trials. The American Thoracic Society has convened a group of experts in lung fibrosis to discuss and formalize recommendations for preclinical assessment of antifibrotic compounds. The panel considered three major themes (choice of animal, practical considerations of fibrosis modeling, and fibrotic endpoints for evaluation). Recognizing the need for practical considerations, we have taken a pragmatic approach. The consensus view is that use of the murine intratracheal bleomycin model in animals of both genders, using hydroxyproline measurements for collagen accumulation along with histologic assessments, is the best-characterized animal model available for preclinical testing. Testing of antifibrotic compounds in this model is recommended to occur after the acute inflammatory phase has subsided (generally after Day 7). Robust analyses may also include confirmatory studies in human IPF specimens and validation of results in a second system using in vivo or in vitro approaches. The panel also strongly encourages the publication of negative results to inform the lung fibrosis community. These recommendations are for preclinical therapeutic evaluation only and are not intended to dissuade development of emerging technologies to better understand IPF pathogenesis.

Cthrc1 lowers pulmonary collagen associated with bleomycin-induced fibrosis and protects lung function.

Idiopathic pulmonary fibrosis (IPF) involves collagen deposition that results in a progressive decline in lung function. This process involves activation of Smad2/3 by transforming growth factor (TGF)‐β and Wnt signaling pathways. Collagen Triple Helix Repeat‐Containing‐1 (Cthrc1) protein inhibits Smad2/3 activation. To test the hypothesis that Cthrc1 limits collagen deposition and the decline of lung function, Cthrc1 knockout (Cthrc1−/−) and wild‐type mice (WT) received intratracheal injections of 2.5 U/kg bleomycin or saline. Lungs were harvested after 14 days and Bronchoalveolar lavage (BAL) TGF‐β, IL1‐β, hydroxyproline and lung compliance were assessed. TGF‐β was significantly higher in Cthrc1−/− compared to WT (53.45 ± 6.15 ng/mL vs. 34.48 ± 11.05) after saline injection. Bleomycin injection increased TGF‐β in both Cthrc1−/− (66.37 ± 8.54 ng/mL) and WT (63.64 ± 8.09 ng/mL). Hydroxyproline was significantly higher in Cthrc1−/− compared to WT after bleomycin‐injection (2.676 ± 0.527 μg/mg vs. 1.889 ± 0.520, P = 0.028). Immunohistochemistry of Cthrc1‐/‐ lung sections showed intracellular localization and activation of β‐catenin Y654 in areas of tissue remodeling that was not evident in WT. Lung compliance was significantly reduced by bleomycin in Cthrc1−/− but there was no effect in WT animals. These data suggest Cthrc1 reduces fibrotic tissue formation in bleomycin‐induced lung fibrosis and the effect is potent enough to limit the decline in lung function. We conclude that Cthrc1 plays a protective role, limiting collagen deposition and could form the basis of a novel therapy for pulmonary fibrosis.