Inhaled B7 alleviates bleomycin-induced pulmonary fibrosis in mice.

Treatment options for the progression of pulmonary fibrosis (PF), which ultimately causes respiratory failure, are limited. According to recent studies, recombinant human relaxin is potentially therapeutic against fibrosis and contraction during pulmonary damage. However, the production of recombinant H2 relaxin is laborious and expensive, limiting its extensive application. Thankfully, alternative research has revealed that treatment with a single-chain peptide of relaxin attenuates organ fibrosis in rodent models too, with the production of a single-chain peptide of relaxin simple and cheap; it could be therapeutic against idiopathic pulmonary fibrosis. Here, we explored the probable inhibiting effects of B7, a B chain of recombinant human relaxin, on bleomycin-induced pulmonary inflammation. Inhaled B7 efficiently reduced the number of inflammatory leukocytes and neutrophils in the bronchoalveolar lavage fluid of mice with bleomycin-induced PF, significantly improved the structure of the damaged alveolar, reduced collagen deposition, suppressed the main pathological features of idiopathic pulmonary fibrosis, i.e. the expression of both pulmonary α-smooth muscle actin and pulmonary vimentin, and inhibited the transcription of inflammation and collagen deposition-related mRNAs, including fibronectin, α-smooth muscle actin (α-SMA), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and alpha-1 type 1 collagen (Col-1a), and the expression of inflammation-related proteins, such as IL-1ß, IL-6, chemokines (KC), TIMP metallopeptidase inhibitor 1 (TIMP-1), and hydroxyproline (Hyp). Overall, our findings suggest that inhaled B7 exerts beneficial effects against pulmonary fibrosis via attenuating inflammation. It could be developed into a simple, highly effective therapeutic approach for pulmonary fibrosis.

The unique molecular targets associated antioxidant and antifibrotic activity of curcumin in in vitro model of acute lung injury: A proteomic approach.

Bleomycin (BLM) injury is associated with the severity of acute lung injury (ALI) leading to fibrosis, a high-morbidity, and high-mortality respiratory disease of unknown etiology. BLM-induced ALI is marked by the activation of a potent fibrogenic cytokine transcription growth factor beta-1 (TGFß-1), which is considered a critical cytokine in the progression of alveolar injury. Previously, our work demonstrated that a diet-derived compound curcumin (diferuloylmethane), represents its antioxidative and antifibrotic application in TGF-ß1-mediated BLM-induced alveolar basal epithelial cells. However, curcumin-specific protein targets, as well as its mechanism using mass spectrometry-based proteomic approach, remain elusive. To elucidate the underlying mechanism, a quantitative proteomics approach and bioinformatics analysis were employed to identify the protein targets of curcumin in BLM or TGF-ß1-treated cells. With subsequent in vitro experiments, curcumin-related pathways and cellular processes were predicted and validated. The current study discusses two separate proteomics experiments using BLM and TGF-ß1-treated cells with the proteomics approach, various unique target proteins were identified, and proteomic analysis revealed that curcumin reversed the expressions of unique proteins like DNA topoisomerase 2-alpha (TOP2A), kinesin-like protein (KIF11), centromere protein F (CENPF), and so on BLM or TGF-ß1 injury. For the first time, the current study reveals that curcumin restores TGF-ß1 induced peroxisomes like PEX-13, PEX-14, PEX-19, and ACOX1. This was verified by subsequent in vitro assays. This study generated molecular evidence to deepen our understanding of the therapeutic role of curcumin at the proteomic level and may be useful to identify molecular targets for future drug discovery.

Evogliptin attenuates bleomycin-induced lung fibrosis via inhibiting TGF-ß/Smad signaling in fibroblast.

OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is a pulmonary interstitial fibrosis disease. Excessive activation of fibroblasts in the lung contributes to severe alveoli dysfunction and histological destruction. Evogliptin, a dipeptidyl peptidase IV inhibitor, has been widely used to reduce glucose level in type 2 diabetes, whereas evogliptin treatment to fibrosis process of lung IPF is elusive. The study aimed to investigate the mechanism of evogliptin in transforming growth factor-beta (TGF-ß)-activated lung fibroblasts and evaluate the efficacy of evogliptin in lung fibrosis model. MATERIALS AND METHODS: In lung fibroblast culture, the RNA expression of α-SMA in lung fibroblasts was detected, and α-SMA/COL-1 immunofluorescence co-staining after TGF-ß stimulation and evogliptin administration was displayed. Mechanically, the phosphorylation level of Smad2/3 protein in cells was analyzed using Western blotting, and the scratch assay was used to reflect fibroblast proliferation. Furthermore, bleomycin was employed to induce lung fibrosis in mice, and IHC staining and hematoxylin and eosin (HE) & Masson staining were carried out to examine the extracellular matrix (ECM) expression and tissue fibrosis. RESULTS: The results demonstrated that evogliptin treatment attenuated the activation of fibroblasts and collagen deposition following TGF-ß stimulation. Furthermore, the extracellular matrix expression was descended via evogliptin restraining the TGF-ß/Smad pathway. Besides, it was also found that evogliptin affected the proliferation degree of lung fibroblasts. In vivo, the COL-1 and α-SMA were significantly reduced through evogliptin treatment compared with the bleomycin group, and fibroblasts and collagenous fiber were remarkably decreased. CONCLUSIONS: Evogliptin exerts an anti-fibrosis effect on TGF-ß induced lung fibroblast activation, which restrains ECM formation and decreases cell proliferation level in fibroblasts. Moreover, the fibroblast infiltration and collagen deposition were ameliorated following evogliptin administration. Therefore, evogliptin serves as a potential implication to protect lung fibrosis.

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-ß1 (TGF-ß1). 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.

Astragaloside IV modulates TGF-ß1-dependent epithelial-mesenchymal transition in bleomycin-induced pulmonary fibrosis.

Epithelial-mesenchymal transition (EMT) plays an important role in idiopathic pulmonary fibrosis (IPF). Astragaloside IV (ASV), a natural saponin from astragalus membranaceus, has shown anti-fibrotic property in bleomycin (BLM)-induced pulmonary fibrosis. The current study was undertaken to determine whether EMT was involved in the beneficial of ASV against BLM-induced pulmonary fibrosis and to elucidate its potential mechanism. As expected, in BLM-induced IPF, ASV exerted protective effects on pulmonary fibrosis and ASV significantly reversed BLM-induced EMT. Intriguing, transforming growth factor-ß1 (TGF-ß1) was found to be up-regulated, whereas Forkhead box O3a (FOXO3a) was hyperphosphorylated and less expressed. However, ASV treatment inhibited increased TGF-ß1 and activated FOXO3a in lung tissues. TGF-ß1 was administered to alveolar epithelial cells A549 to induce EMT in vitro. Meanwhile, stimulation with TGF-ß1-activated phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway and induced FOXO3a hyperphosphorylated and down-regulated. It was found that overexpression of FOXO3a leading to the suppression of TGF-ß1-induced EMT. Moreover, ASV treatment, similar with the TGF-ß1 or PI3K/Akt inhibitor, reverted these cellular changes and inhibited EMT in A549 cells. Collectively, the results suggested that ASV significantly inhibited TGF-ß1/PI3K/Akt-induced FOXO3a hyperphosphorylation and down-regulation to reverse EMT during the progression of fibrosis.

VCE-004.3, a cannabidiol aminoquinone derivative, prevents bleomycin-induced skin fibrosis and inflammation through PPARγ- and CB2 receptor-dependent pathways.

BACKGROUND AND PURPOSE: The endocannabinoid system and PPARγ are important targets for the development of novel compounds against fibrotic diseases such as systemic sclerosis (SSc), also called scleroderma. The aim of this study was to characterize VCE-004.3, a novel cannabidiol derivative, and study its anti-inflammatory and anti-fibrotic activities. EXPERIMENTAL APPROACH: The binding of VCE-004.3 to CB1 and CB2 receptors and PPARγ and its effect on their functional activities were studied in vitro and in silico. Anti-fibrotic effects of VCE-004.3 were investigated in NIH-3T3 fibroblasts and human dermal fibroblasts. To assess its anti-inflammatory and anti-fibrotic efficacy in vivo, we used two complementary models of bleomycin-induced fibrosis. Its effect on ERK1/2 phosphorylation induced by IgG from SSc patients and PDGF was also investigated. KEY RESULTS: VCE-004.3 bound to and activated PPARγ and CB2 receptors and antagonized CB1 receptors. VCE-004.3 bound to an alternative site at the PPARγ ligand binding pocket. VCE-004.3 inhibited collagen gene transcription and synthesis and prevented TGFß-induced fibroblast migration and differentiation to myofibroblasts. It prevented skin fibrosis, myofibroblast differentiation and ERK1/2 phosphorylation in bleomycin-induced skin fibrosis. Furthermore, it reduced mast cell degranulation, macrophage activation, T-lymphocyte infiltration, and the expression of inflammatory and profibrotic factors. Topical application of VCE-004.3 also alleviated skin fibrosis. Finally, VCE-004.3 inhibited PDGF-BB- and SSc IgG-induced ERK1/2 activation in fibroblasts. CONCLUSIONS AND IMPLICATIONS: VCE-004.3 is a novel semisynthetic cannabidiol derivative that behaves as a dual PPARγ/CB2 agonist and CB1 receptor modulator that could be considered for the development of novel therapies against different forms of scleroderma.

AQX-1125, small molecule SHIP1 activator inhibits bleomycin-induced pulmonary fibrosis.

BACKGROUND AND PURPOSE: The phosphatase SHIP1 negatively regulates the PI3K pathway, and its predominant expression within cells of the haematopoietic compartment makes SHIP1 activation a novel strategy to limit inflammatory signalling generated through PI3K. AQX-1125 is the only clinical-stage, orally administered, SHIP1 activator. Here, we demonstrate the prophylactic and therapeutic effects of AQX-1125, in a mouse model of bleomycin-induced lung fibrosis. EXPERIMENTAL APPROACH: For prophylactic evaluation, AQX-1125 (3, 10 or 30 mg·kg-1 ·d-1 , p.o.) or dexamethasone (1 mg·kg-1 ·d-1 , i.p.) were given to CD-1 mice starting 3 days before intratracheal administration of bleomycin (0.1 IU per mouse) and continued daily for 7 or 21 days. Therapeutic potentials of AQX-1125 (3, 10 or 30 mg·kg-1 ·d-1 , p.o.) or pirfenidone (90 mg·kg-1 ·d-1 , p.o.) were assessed by initiating treatment 13 days after bleomycin instillation and continuing until day 28. KEY RESULTS: Given prophylactically, AQX-1125 (10 and 30 mg·kg-1 ) reduced histopathological changes in lungs, 7 and 21 days following bleomycin-induced injury. At the same doses, AQX-1125 reduced the number of total leukocytes, neutrophil activity, TGF-ß immunoreactivity and soluble collagen in lungs. Administered therapeutically, AQX-1125 (10 and 30 mg·kg-1 ) improved lung histopathology, cellular infiltration and reduced lung collagen content. At 30 mg·kg-1 , the effects of AQX-1125 were similar to those of pirfenidone (90 mg·kg-1 ) with corresponding improvements in disease severity. CONCLUSIONS AND IMPLICATIONS: AQX-1125 prevented bleomycin-induced lung injury during the inflammatory and fibrotic phases. AQX-1125, given therapeutically, modified disease progression and improved survival, as effectively as pirfenidone.

Emodin alleviates bleomycin-induced pulmonary fibrosis in rats.

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease with few treatment options and poor prognosis. Emodin, extracted from Chinese rhubarb, was found to be able to alleviate bleomycin (BLM)-induced pulmonary fibrosis, yet the underlying mechanism remains largely unknown. This study aimed to further investigate the effects of emodin on the inflammation and fibrosis of BLM-induced pulmonary fibrosis and the mechanism involved in rats. Our results showed that emodin improved pulmonary function, reduced weight loss and prevented death in BLM-treated rats. Emodin significantly relieved lung edema and fibrotic changes, decreased collagen deposition, and suppressed the infiltration of myofibroblasts [characterized by expression of α-smooth muscle actin (α-SMA)] and inflammatory cells (mainly macrophages and lymphocytes). Moreover, emodin reduced levels of TNF-α, IL-6, TGF-ß1 and heat shock protein (HSP)-47 in the lungs of BLM-treated rats. In vitro, emodin profoundly inhibited TGF-ß1-induced α-SMA, collagen IV and fibronectin expression in human embryo lung fibroblasts (HELFs). Emodin also inhibited TGF-ß1-induced Smad2/3 and STAT3 activation, indicating that Smad2/3 and STAT3 inactivation mediates emodin-induced effects on TGF-ß1-induced myofibroblast differentiation. These results suggest that emodin can exert its anti-fibrotic effect via suppression of TGF-ß1 signaling and subsequently inhibition of inflammation, HSP-47 expression, myofibroblast differentiation and extracellular matrix (ECM) deposition.

Total glycosides of Yupingfeng protects against bleomycin-induced pulmonary fibrosis in rats associated with reduced high mobility group box 1 activation and epithelial-mesenchymal transition.

BACKGROUND: Pulmonary fibrosis (PF) is a fatal inflammatory disease with limited effective strategies. Epithelial-mesenchymal transition (EMT) is a pivotal origin of myofibroblasts that secrete extracellular matrix (ECM) in the development of PF. High mobility group box 1 (HMGB1), one of the mediators of inflammation, has been proved abnormal activation in the pathogenesis of PF. AIM: The present study was aimed to investigate the potential effects of total glycoside of Yupingfeng (YPF-G), the natural compound extracted from Yupingfeng san, on HMGB1 activation and EMT in bleomycin-induced PF, which was a serious disease of respiratory system. METHODS: The Sprague-Dawley (SD) rat model of PF was duplicated by intratracheal instillation of bleomycin (5 mg kg(-1)). After that, YPF-G (5, 10 mg kg(-1)) and prednisone (5 mg kg(-1)) were separately administered intragastrically, and then the rats were killed at days 14 and 28, respectively. Hematoxylin and eosin and Masson's trichrome staining were performed to assess the histopathologic level of lung tissues, western blotting and the common kits were utilized to investigate the hallmarks molecule expression of ECM and EMT, and the level of HMGB1 in lung tissues and serum. RESULTS: We found that both dose of YPF-G markedly reduced bleomycin-induced alveolitis and PF in rats. Besides, the levels of HMGB1, laminin, hyaluronic acid, and hydroxyproline were effectively reduced. Meanwhile, the increased protein expression of HMGB1 and the mesenchymal markers including vimentin and alpha-smooth muscle actin, and the decreased protein expression of epithelial marker E-cadherin were dramatically inhibited after YPF-G treatment. CONCLUSION: Our results demonstrated that YPF-G could ameliorate bleomycin-induced PF by reducing HMGB1 activation and reversing EMT.

Epigenetic suppression of Fli1, a potential predisposing factor in the pathogenesis of systemic sclerosis.

Systemic sclerosis (SSc) is a multisystem connective tissue disease featured by immune abnormalities, vasculopathy and tissue fibrosis with unknown etiology. A series of studies on disease-susceptibility genes and twins have demonstrated the association of genetic factors with autoimmunity and disease severity and the contribution of environmental factors to the induction of clinical features in this disease. Friend leukemia virus integration 1 (Fli1), a member of Ets transcription factor family, is epigenetically suppressed in the lesional skin of SSc patients, suggesting that Fli1 is a potential predisposing factor of SSc reflecting the influence of environmental factors. Consistent with this idea, Fli1 deficiency induces SSc-like phenotypes in dermal fibroblasts and dermal microvascular endothelial cells in vivo and in vitro at molecular levels. Furthermore, Fli1 haploinsufficiency recapitulates tissue fibrosis, vascular activation and inflammation characteristic of SSc to a greater extent in bleomycin-treated mice. Importantly, bosentan, a dual endothelin receptor antagonist with a potential disease-modifying effect on SSc vasculopathy, reverses the expression of Fli1 protein by increasing its protein stability. Therefore, Fli1 may serve as a predisposing factor of SSc and can be a promising therapeutic target of this incurable and devastating disease. This article is part of a Directed Issue entitled: Epigenetics dynamics in development and disease.

Bleomycin in the setting of lung fibrosis induction: From biological mechanisms to counteractions.

Bleomycin (BLM) is a drug used to treat different types of neoplasms. BLM's most severe adverse effect is lung toxicity, which induces remodeling of lung architecture and loss of pulmonary function, rapidly leading to death. While its clinical role as an anticancer agent is limited, its use in experimental settings is widespread since BLM is one of the most widely used drugs for inducing lung fibrosis in animals, due to its ability to provoke a histologic lung pattern similar to that described in patients undergoing chemotherapy. This pattern is characterized by patchy parenchymal inflammation, epithelial cell injury with reactive hyperplasia, epithelial-mesenchymal transition, activation and differentiation of fibroblasts to myofibroblasts, basement membrane and alveolar epithelium injuries. Several studies have demonstrated that BLM damage is mediated by DNA strand scission producing single- or double-strand breaks that lead to increased production of free radicals. Up to now, the mechanisms involved in the development of pulmonary fibrosis have not been fully understood; several studies have analyzed various potential biological molecular factors, such as transforming growth factor beta 1, tumor necrosis factor alpha, components of the extracellular matrix, chaperones, interleukins and chemokines. The aim of this paper is to review the specific characteristics of BLM-induced lung fibrosis in different animal models and to summarize modalities and timing of in vivo drug administration. Understanding the mechanisms of BLM-induced lung fibrosis and of commonly used therapies for counteracting fibrosis provides an opportunity for translating potential molecular targets from animal models to the clinical arena.

Silymarin alleviates bleomycin-induced pulmonary toxicity and lipid peroxidation in mice.

CONTEXT: The application of bleomycin is limited due to its side effects including lung toxicity. Silymarin is a flavonoid complex isolated from milk thistle [Silybum marianum L. (Asteraceae)] which has been identified as an antioxidant and anti-inflammatory compound. OBJECTIVE: This study evaluates the effect of silymarin on oxidative and inflammatory parameters in the lungs of mice exposed to bleomycin. MATERIALS AND METHODS: BALB/c mice were divided into four groups of control, bleomycin (1.5 U/kg), bleomycin plus silymarin (50 and 100 mg/kg). After bleomycin administration, mice received 10 d intraperitoneal silymarin treatment. On 10th day, blood and lung samples were collected for measurement of oxidative and inflammatory factors. RESULTS: Silymarin led to a decrease in lung lipid peroxidation (0.19 and 0.17 nmol/mg protein) in bleomycin-injected animals. Glutathione-S-transferase (GST) which was inhibited by bleomycin (32.4 nmol/min/mg protein) induced by higher dose of silymarin (41 nmol/min/mg protein). Silymarin caused an elevation in glutathione (GSH): 2.6 and 3.1 µmol/g lung compare with bleomycin-injected animals 1.8 µmol/g lung. Catalase (CAT) was increased due to high dose of silymarin (65.7 µmol/min/ml protein) compare with bleomycin treated-mice. Myeloperoxidase (MPO) which was induced due to bleomycin (p < 0.05) reduced again by high dose of silymarin (0.51 U/min/mg protein). Bleomycin led to an increase in TNF-α and interleukin-6 (IL-6) (7.9 and 11.8 pg/ml). These parameters were reduced by silymarin (p < 0.05). CONCLUSIONS: Silymarin attenuated bleomycin induced-pulmonary toxicity. This protective effect may be due to the ability of silymarin in keeping oxidant-antioxidant balance and regulating of inflammatory mediator release.

Arsenic trioxide inhibits transforming growth factor-ß1-induced fibroblast to myofibroblast differentiation in vitro and bleomycin induced lung fibrosis in vivo.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease of insidious onset, and is responsible for up to 30,000 deaths per year in the U.S. Excessive production of extracellular matrix by myofibroblasts has been shown to be an important pathological feature in IPF. TGF-ß1 is expressed in fibrotic lung and promotes fibroblast to myofibroblast differentiation (FMD) as well as matrix deposition. METHODS: To identify the mechanism of Arsenic trioxide's (ATO)'s anti-fibrotic effect in vitro, normal human lung fibroblasts (NHLFs) were treated with ATO for 24 hours and were then exposed to TGF-ß1 (1 ng/ml) before harvesting at multiple time points. To investigate whether ATO is able to alleviate lung fibrosis in vivo, C57BL/6 mice were administered bleomycin by oropharyngeal aspiration and ATO was injected intraperitoneally daily for 14 days. Quantitative real-time PCR, western blotting, and immunofluorescent staining were used to assess the expression of fibrotic markers such as α-smooth muscle actin (α-SMA) and α-1 type I collagen. RESULTS: Treatment of NHLFs with ATO at very low concentrations (10-20nM) inhibits TGF-ß1-induced α-smooth muscle actin (α-SMA) and α-1 type I collagen mRNA and protein expression. ATO also diminishes the TGF-ß1-mediated contractile response in NHLFs. ATO's down-regulation of profibrotic molecules is associated with inhibition of Akt, as well as Smad2/Smad3 phosphorylation. TGF-ß1-induced H2O2 and NOX-4 mRNA expression are also blocked by ATO. ATO-mediated reduction in Smad3 phosphorylation correlated with a reduction of promyelocytic leukemia (PML) nuclear bodies and PML protein expression. PML-/- mouse embryonic fibroblasts (MEFs) showed decreased fibronectin and PAI-1 expression in response to TGF-ß1. Daily intraperitoneal injection of ATO (1 mg/kg) in C57BL/6 mice inhibits bleomycin induced lung α-1 type I collagen mRNA and protein expression. CONCLUSIONS: In summary, these data indicate that low concentrations of ATO inhibit TGF-ß1-induced fibroblast to myofibroblast differentiation and decreases bleomycin induced pulmonary fibrosis.

Chronic alcohol ingestion primes the lung for bleomycin-induced fibrosis in mice.

BACKGROUND: Alcohol abuse increases the risk for acute lung injury (ALI). In both experimental models and in clinical studies, chronic alcohol ingestion causes airway oxidative stress and glutathione depletion and increases the expression of transforming growth factor beta-1 (TGFß1), a potent inducer of fibrosis, in the lung. Therefore, we hypothesized that alcohol ingestion could promote aberrant fibrosis following experimental ALI and that treatment with the glutathione precursor s-adenosylmethionine (SAMe) could mitigate these effects. METHODS: Three-month-old C57BL/6 mice were fed standard chow ± alcohol (20% v/v) in their drinking water for 8 weeks and ±SAMe (4% w/v) during the last 4 weeks. ALI was induced by intratracheal instillation of bleomycin (2.5 units/kg), and lungs were assessed histologically at 7 and 14 days for fibrosis and at 14 days for the expression of extracellular matrix proteins and TGFß1. RESULTS: Alcohol ingestion had no apparent effect on lung inflammation at 7 days, but at 14 days after bleomycin treatment, it increased lung tissue collagen deposition, hydroxyproline content, and the release of activated TGFß1 into the airway. In contrast, SAMe supplementation completely mitigated alcohol-induced priming of these aberrant fibrotic changes through decreased TGFß1 expression in the lung. In parallel, SAMe decreased alcohol-induced TGFß1 and Smad3 mRNA expressions by lung fibroblasts in vitro. CONCLUSIONS: These new experimental findings demonstrate that chronic alcohol ingestion renders the experimental mouse lung susceptible to fibrosis following bleomycin-induced ALI, and that these effects are likely driven by alcohol-mediated oxidative stress and its induction and activation of TGFß1.

Hydrogen sulfide protects against bleomycin-induced pulmonary fibrosis in rats by inhibiting NF-κB expression and regulating Th1/Th2 balance.

Hydrogen sulfide (H2S) displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. The objective of this study was to evaluate the inhibitory effect of H2S on bleomycin (BLM)-induced pulmonary fibrosis in rats and its possible mechanisms. Fifty-four pathogen-free Male Wistar rats were randomly divided into three groups: control, BLM and H2S treated groups with 18 rats in each group. Each group was then divided into three subgroups based on time of study (7, 14 and 28 day). Pulmonary fibrosis model was established by a single intratracheal instillation of BLM A5 (5 mg/kg). While control rats received saline, rats of the treated group simultaneously were administered intraperitoneal injections of NaHS (the H2S donor, 28 µmol/kg) once daily. BLM induced pulmonary inflammation and fibrosis, increased lung hydroxyproline levels, lung index, total cell counts, neutrophils and eosinophils counts and expression of NF-κB p65 in lung tissue, decreased lymphocytes and macrophages counts. In addition, Th1 response is suppressed as shown by diminished IFN-γ in bronchoalveolar lavage fluid (BALF) after BLM exposure, and enhancement of Th2 response is marked by increased IL-4 in BALF. H2S administration significantly attenuated these effects. The findings reveal the therapeutic potential of H2S for BLM-induced pulmonary fibrosis in male rats, which were at least partly due to inhibition NF-κB p65 expression and regulation of Th1/Th2 balance.

All-transretinoic acid ameliorates bleomycin-induced lung fibrosis by downregulating the TGF-ß1/Smad3 signaling pathway in rats.

The transforming growth factor-ß1 (TGF-ß1)/Smad3 signaling pathway has a central role in pathogenesis of lung fibrosis. In the present study, we investigated if all-trans retinoic acid (ATRA) could attenuate fibrosis in bleomycin (BLM)-induced lung fibrosis in rats through regulating TGF-ß1/Smad3 signaling. Beginning on day 14 after BLM administration, the ATRA I and II groups of rats received daily oral administration of ATRA for 14 days. All rats were killed on day 28. Lung tissue sections were prepared and subject to histological assessment, and expression levels of proteins involved in the TGF-ß1 signaling cascade and epithelial-mesenchymal transition (EMT) were evaluated by transmission electron microscopy (TEM), quantitative real-time polymerase chain reaction (qRT-PCR), western blot procedure, and immunohistochemical or immunofluorescence staining. BLM significantly increased the alveolar septum infiltrates, inflammatory cell infiltrates, and collagen fibers. These BLM-induced changes were significantly ameliorated by ATRA treatment. In addition, BLM significantly increased levels of lung fibrosis markers α-SMA, hydroxyproline (Hyp), collagen I, Snail, and Twist, whereas significantly decreased E-cadherin expression. ATRA treatment largely reversed BLM-induced changes in these lung fibrosis markers. ATRA also blocked BLM-induced activation of the TGF-ß1/Smad3 signaling pathway in lung tissues, including expression of TGF-ß1, Smad3, p-Smad3, zinc-finger E-box-binding homeobox 1 and 2 (ZEB1 and ZEB2), and the high-mobility group AT-hook 2 (HMGA2). Our results suggest that ATRA may have potential therapeutic value for lung fibrosis treatment.

Evaluating the inhibitory potential of sulindac against the bleomycin-induced pulmonary fibrosis in wistar rats.

The present study examined the protective effect of sulindac on bleomycin-induced lung fibrosis in rats. Animals were divided into saline group, bleomycin group (single intra-tracheal instillation of bleomycin) and bleomycin+sulindac (orally from day 1 to day 20). Bleomycin administration reduced the body weight, altered antioxidant status (such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione) while it increased the lung weight, hydroxyproline content, collagen deposition and lipid peroxidation. However, simultaneous administration of sulindac improved the body weight, antioxidant status and decreased the collagen deposition in lungs. Moreover, the levels of inflammatory cytokine tumour necrosis factor-α increased in bleomycin-induced group, whereas, on treatment with sulindac the levels of tumour necrosis factor-α were found reduced. Finally, histological evidence also supported the ability of sulindac to inhibit bleomycin-induced lung fibrosis. The results of the present study indicate that sulindac can be used as an agent against bleomycin-induced pulmonary fibrosis.

Bleomycin-induced pulmonary fibrosis is attenuated by an antibody against KL-6.

BACKGROUND: Elevated levels of KL-6 are reported in the serum and/or bronchoalveolar lavage fluid (BALF) of patients with interstitial lung disease (ILD) and are useful to estimate the severity and prognosis of the disease. However, whether the anti-KL-6 antibody could attenuate pulmonary fibrosis remains unclear. OBJECTIVES: This study aims to investigate the therapeutic effects and mechanisms of anti-KL-6 antibody on bleomycin-induced pulmonary fibrosis. METHODS: A mouse model of pulmonary fibrosis was established by intratracheal injection of bleomycin (5 mg/kg). Mouse received anti-KL-6 antibody (20 ug/day, once a day) from day 7 to 21 after bleomycin injection. The effects of anti-KL-6 antibody were evaluated by pathological examination, measuring hydroxyproline measurements in lung tissues, leukocyte counts in BALF and the expression of collagen type I and type III using qRT-PCR. The expression of profibrotic cytokine (transforming growth factor-ß1, TGF-ß1), antifibrotic cytokine (hepatocyte growth factor, HGF), and KL-6 in lung tissues were analyzed by ELISA. The apoptosis of epithelial cell was examined by TUNEL staining. RESULTS: Anti-KL-6 antibody significantly reduced the number of alveolar inflammatory leukocytes (total and differential counts) in BALF of mice with bleomycin-induced pulmonary fibrosis as well as the content of hydroxyproline in the lung tissues. Treatment with anti-KL-6 antibody downregulated the expression of collagen type I, TGF-ß1 and KL-6, upregulated the expression of HGF and inhibited the apoptosis of epithelial cells. CONCLUSIONS: These findings indicated the anti-KL-6 antibody may potentially be developed as a useful inhibitor of pulmonary fibrosis.

Berberine attenuates bleomycin induced pulmonary toxicity and fibrosis via suppressing NF-κB dependant TGF-ß activation: a biphasic experimental study.

Idiopathic pulmonary fibrosis (IPF) is a progressive, debilitating and fatal lung disorder with high mortality rate. Unfortunately, to date the treatment for IPF remains unsatisfying and in severe cases lung transplantations are performed as a therapeutic measure. Thus, it becomes great interest to find novel agents to treat IPF. Berberine, a plant alkaloid known for its broad pharmacological activities remains a remedy against multiple diseases. This study was hypothesized to investigate the antifibrotic potential of berberine against bleomycin-induced lung injury and fibrosis, a tentative animal model. Male wistar rats were subjected to single intratracheal instillation of 2.5 U/kg of bleomycin on day 0. Berberine treatments were either provided in preventive or therapeutic mode respectively. Berberine administration significantly ameliorated the bleomycin mediated histological alterations and reduced the inflammatory cell infiltrate in BALF. Berberine significantly blocked collagen accumulations with parallel reduction in the hydroxyproline level. The immunological sign of bleomycin stimulated mast cell deposition and histamine release were considerably reduced by berberine. Berberine enhanced the antioxidant status, through upregulating the redox sensing transcription factor nuclear factor E2-related factor 2 (Nrf2). Berberine inhibited the bleomycin mediated activation of inflammatory mediator nuclear factor kappa B (NF-κB) and suppressed its downstream target inducible nitric oxide synthase (iNOS). Strikingly, berberine exhibited target attenuation of tumor necrosis factor alpha (TNF-α) and key pro-fibrotic mediator, transforming growth factor beta 1 (TGF-ß1). Taken together, this study reveals the beneficial effects of berberine against bleomycin mediated fibrotic challenge through activating Nrf2 and suppressing NF-κB dependent inflammatory and TGF-ß1 mediated fibrotic events.

Effect of thiol compounds on bleomycin-induced DNA and chromosome damage in human cells.

Non-protein thiols are considered radioprotectors, preventing DNA damage by ionizing radiation. As bleomycin (BLM) is a radiomimetic agent it was proposed that thiols may prevent DNA damage produced by this antibiotic. However, results obtained with thiols and BLM-combined treatments in living cells are contradictory. The goal of this work was to assess the influence of five non-protein thiols of different electrical charge and chemical composition, on the DNA damage, DNA repair, chromosomal aberrations and cell killing induced by BLM. We found that, at the chromosomal level and cell killing, Glutathione, ß-Mercaptoethanol and cysteine showed a protective effect, while ditiothreitol and cysteamine increased them, whereas at the DNA level all thiols potentiated the DNA damage induced by BLM, most probably due to a reactivation of the BLM complex.