Potent antioxidant role of pirfenidone in experimental cirrhosis. Eur J Pharmacol. 2008;595:69-77. [PMID: 18652820 DOI: 10.1016/j.ejphar.2008.06.110]

Pirfenidone affects human cardiac fibroblast proliferation and cell cycle activity in 2D cultures and engineered connective tissues

The anti-fibrotic drug pirfenidone (PFD) is currently in clinical testing for the treatment of heart failure with preserved ejection fraction; however, its effects on human cardiac cells have not been fully investigated. Therefore, we aimed to characterize the impact of PFD on human cardiac fibroblasts (CF) in 2D culture as well as in 3D-engineered connective tissues (ECT). We analyzed proliferation by automated cell counting and changes in signaling by immunoblotting. We generated ECT with different geometries to modify the cellular phenotype and investigated the effects of PFD on cell number and viability as well as on cell cycle activity. We further studied its effect on ECT compaction, contraction, stiffening, and strain resistance by ECT imaging, pole deflection analysis, and ultimate tensile testing. Our data demonstrate that PFD inhibits human CF proliferation in a concentration-dependent manner with an IC50 of 0.43 mg/ml and its anti-mitogenic effect was further corroborated by an inhibition of MEK1/2, ERK1/2, and riboprotein S6 (rpS6) phosphorylation. In ECT, a lower cell cycle activity was found in PFD-treated ECT and fewer cells resided in these ECT after 5 days of culture compared to the control. Moreover, ECT compaction as well as ECT contraction was impaired. Consequently, biomechanical analyses demonstrated that PFD reduced the stiffness of ECT. Taken together, our data demonstrate that the anti-fibrotic action of PFD on human CF is based on its anti-mitogenic effect in 2D cultures and ECT.

A Substituted-Rhodamine-Based Reversible Fluorescent Probe for In Vivo Quantification of Glutathione

Quantifying glutathione (GSH) in cells and organisms is of great significance for understanding the mechanism of oxidative stress in various physiological and pathological processes. However, the quantification by fluorescence bioimaging in living tissues has much stricter requirements than the "Petri dish"-cultured cells in flat plates. Based on the evaluation of the electronic structure and steric hindrance-tuned reactivity of phospha-substituted rhodamine with GSH, a reversible Förster resonance energy transfer (FRET) probe ZpSiP with a distinct performance (K_d =4.9 mM, t_1/2 =0.57 s, k=81 M^-1  s^-1 ) is developed for real time quantifying GSH in living cells. Furthermore, the near-infrared (NIR) probe succeeded in sensitively tracking the dynamics of GSH in the real organisms bearing tumors, chronic renal failure, and liver fibrosis for unveiling the related pathological processes. We believe that the advance in chemistry with quantitative analysis methods will initiate more promising progress and broad applications.

Innovated pirfenidone loaded lecithin nanocapsules for targeting liver fibrosis: Formulation, characterization and in vivo study

Increasing interest in developing antifibrotic therapies became a paramount priority due to the globally raised incidence of deaths secondary to hepatic cirrhosis. This work deals with the development of innovative antifibrotic pirfenidone -loaded lecithin core nanocapsules. This with the intention to target the liver and to increase the drug bioavailability, reducing drug liver toxicity, and studying the associated hepatic microenvironment changes. PFD-loaded lecithin nanocapsules (PFD-LENCs) were prepared using the natural lipoid S45 for its dual benefits of being both a lipid and an amphiphilic surfactant. The selected formulation exhibited in vitro sustained drug release up to 24 h compared to free PFD, which is consistent with the studied pharmacokinetic profile. The studied cytotoxicity of PFD as well as PFD-LENCs exhibited negligible cytotoxicity in normal oral epithelial cells. For exploring the capability of the PFD-LENCs in reaching the liver; in vivo tracing using CLSM, in vivo biodistribution to the vital organs were conducted and electron microscopic examination for depicting nanoparticles in liver tissue was performed. Results revealed the capability of the prepared fluorescent LENC2 in reaching the liver, PFD-LENCs detection in the Disse space of the liver and the significant accumulation of PFD-LENCs in liver tissue compared to the other tested organs. The assessment of the necro-inflammatory, antioxidant and the anti-fibrotic effect of PFD-LENCs (50 & 100 mg/kg) exhibited a significant decrease of liver enzymes, TNF-α, TGF-β, Col-1, α-SMA, and TIMP-1, and a significant increase of catalase enzyme and MMP2 compared to free PFD. EM studies, revealed often detection of dendritic cells in PFD-LENCs (100 mg/kg) treated mice and abnormal collagen structure which can represent an adjunct contribution to the antifibrotic mechanism of PFD-LENCs. In conclusion, the development of this innovative PFD loaded lecithin nanocapsules achieved a targeting ability to the liver, controlled drug release, thereby increase the PFD therapeutic value in downregulating hepatic fibrosis in adjunct with the reduction of liver toxicity.

Investigating the possible mechanisms of pirfenidone to be targeted as a promising anti-inflammatory, anti-fibrotic, anti-oxidant, anti-apoptotic, anti-tumor, and/or anti-SARS-CoV-2

Pirfenidone (PFD) is a non-peptide synthetic chemical that inhibits the production of transforming growth factor-beta 1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), platelet-derived growth factor (PDGF), Interleukin 1 beta (IL-1β), and collagen 1 (COL1A1), all of which have been linked to the prevention or removal of excessive scar tissue deposition in many organs. PFD has been demonstrated to decrease apoptosis, downregulate angiotensin-converting enzyme (ACE) receptor expression, reduce inflammation through many routes, and alleviate oxidative stress in pneumocytes and other cells while protecting them from COVID-19 invasion and cytokine storm. Based on the mechanism of action of PFD and the known pathophysiology of COVID-19, it was recommended to treat COVID-19 patients. The use of PFD as a treatment for a range of disorders is currently being studied, with an emphasis on outcomes related to reduced inflammation and fibrogenesis. As a result, rather than exploring the molecule's chemical characteristics, this review focuses on innovative PFD efficacy data. Briefly, herein we tried to investigate, discuss, and illustrate the possible mechanisms of actions for PFD to be targeted as a promising anti-inflammatory, anti-fibrotic, anti-oxidant, anti-apoptotic, anti-tumor, and/or anti-SARS-CoV-2 candidate.

A new approach based on CXCR4-targeted combination liposomes for the treatment of liver fibrosis

Liver fibrosis results from excessive extracellular matrix accumulation due to injury and leads to cirrhosis, cancer, and death. Herein, we propose a chemokine receptor 4 (CXCR4)-targeted combination (CTC) liposomal therapy to treat carbon tetrachloride (CCl₄)-induced liver fibrosis in a mouse model. This study aims to combine small molecules such as pirfenidone and AMD3100 in a single nanoplatform to investigate their synergistic antifibrotic effects in a setting of CCl₄-induced liver fibrosis. CTC liposomes (CTC lipo) were prepared using the thin-film hydration method. CTC lipo exhibited a spherical shape, and the particle size was recorded at the nanoscale which confirms its appropriateness for in vitro and in vivo applications. CTC lipo had good storage and serum stability. The entrapped drugs in CTC lipo showed reduced toxicity at higher concentrations. CTC lipo displayed CXCR4 mediated cell uptake and were internalized by caveolae-mediated endocytosis. CTC lipo showed CXCR4 targeting and stromal cell-derived factor 1α (SDF1-α)/CXCR4 axis blocking activity. CTC lipo reduced the elevated serum aspartate aminotransferase (AST), alanine transaminase (ALT), and hydroxyproline (HYP) levels. The histological studies showed improved liver architecture and reduced collagen deposition after treatment. Transforming growth factor β (TGFβ), alpha-smooth muscle actin (α-SMA), and collagen I were elevated by CCl₄ in comparison with the Sham. Upon CTC liposomal treatment, the quantitative score for the elevated fibrotic proteins such as TGFβ, α-SMA, and collagen I was normalized. CTC lipo displayed significant downregulation of the upregulated TGFβ, α-SMA, collagen I, and P-p38 expressions at the molecular level. The CXCR4 targeted liposomes showed prolonged biodistribution at 24 h. Our findings indicated that CTC lipo might be an alternative antifibrotic therapy that may offer new access to research and development. In a nutshell, the present study suggests that systemic administration of CTC lipo has efficient antifibrotic potential and deserves to be investigated for further clinical applications.

The Role of Oxidative Stress in Sarcoidosis

Sarcoidosis is a rare, systemic inflammatory disease whose diagnosis and management can pose a challenge for clinicians and specialists. Scientific knowledge on the molecular pathways that drive its development is still lacking, with no standardized therapies available and insufficient strategies to predict patient outcome. In recent years, oxidative stress has been highlighted as an important factor in the pathogenesis of sarcoidosis, involving several enzymes and molecules in the mechanism of the disease. This review presents current data on the role of oxidative stress in sarcoidosis and its interaction with inflammation, as well as the application of antioxidative therapy in the disease.

The anti-fibrotic drug pirfenidone inhibits liver fibrosis by targeting the small oxidoreductase glutaredoxin-1

Activation of the hepatic stellate cells (HSCs) is a key pathogenic event in liver fibrosis. Protein S-glutathionylation (PSSG) of cysteine residues is a distinct form of oxidative response that modifies protein structures and functions. Glutaredoxin-1 (GLRX) reverses PSSG by liberating glutathione (GSH). In this study, we showed that pirfenidone (PFD), an anti-lung fibrosis drug, inhibited HSC activation and liver fibrosis in a GLRX-dependent manner. Glrx depletion exacerbated liver fibrosis, and decreased GLRX and increased PSSG were observed in fibrotic mouse and human livers. In contrast, overexpression of GLRX inhibited PSSG and liver fibrosis. Mechanistically, the inhibition of HSC activation by GLRX may have been accounted for by deglutathionylation of Smad3, which inhibits Smad3 phosphorylation, leading to the suppression of fibrogenic gene expression. Our results have established GLRX as the therapeutic target of PFD and uncovered an important role of PSSG in liver fibrosis. GLRX/PSSG can be both a biomarker and a therapeutic target for liver fibrosis.

Pirfenidone modifies hepatic miRNAs expression in a model of MAFLD/NASH

miRNAs are involved in the development of metabolic associated fatty liver disease (MAFLD) and nonalcoholic steatohepatitis (NASH). We aimed to evaluate modifications by prolonged-release pirfenidone (PR-PFD) on key hepatic miRNAs expression in a MAFLD/NASH model. First, male C57BL/6J mice were randomly assigned into groups and fed with conventional diet (CVD) or high fat and carbohydrate diet (HFD) for 16 weeks. At the end of the eighth week, HFD mice were divided in two and only one half was treated with 300 mg/kg/day of PR-PFD mixed with food. Hepatic expression of miRNAs and target genes that participate in inflammation and lipid metabolism was determined by qRT-PCR and transcriptome by microarrays. Increased hepatic expression of miR-21a-5p, miR-34a-5p, miR-122-5p and miR-103-3p in MAFLD/NASH animals was reduced with PR-PFD. Transcriptome analysis showed that 52 genes involved in lipid and collagen biosynthesis and inflammatory response were downregulated in PR-PFD group. The expression of Il1b, Tnfa, Il6, Tgfb1, Col1a1, and Srebf1 were decreased in PR-PFD treated animals. MAFLD/NASH animals compared to CVD group showed modifications in gene metabolic pathways implicated in lipid metabolic process, inflammatory response and insulin resistance; PR-PFD reversed these modifications.

Pirfenidone regulates LPS mediated activation of neutrophils

Excessive inflammation or its absence may result in impaired wound healing. Neutrophils are among the first innate immune cells to arrive at the injury site. They participate in infection control and debris removal to initiate healing. If not timely resolved, neutrophils can cause excessive tissue inflammation and damage. Drugs with anti-inflammatory and anti-fibrotic effects are of promise for improving healing by balancing the primary defensive functions and excessive tissue damage actions. Of interest, pirfenidone (Pf), an FDA approved anti-fibrotic drug to treat idiopathic pulmonary fibrosis, has been shown to ameliorate inflammation in several animal models including mouse deep partial-thickness burn wounds. However, there is a lack of mechanistic insights into Pf drug action on inflammatory cells such as neutrophils. Here, we examined the treatment effects of Pf on LPS-stimulated neutrophils as a model of non-sterile inflammation. Firstly, Pf reduced chemotaxis and production of pro-inflammatory ROS, cytokines, and chemokines by LPS-activated neutrophils. Secondly, Pf increased anti-inflammatory IL-1RA and reduced neutrophil degranulation, phagocytosis, and NETosis. Thirdly, Pf affected downstream signaling kinases which might directly or indirectly influence neutrophil responses to LPS. In conclusion, the results suggest that Pf lessens the inflammatory phenotypes of LPS-activated neutrophils.

Roles of Nrf2 in Liver Diseases: Molecular, Pharmacological, and Epigenetic Aspects

Liver diseases represent a critical health problem with 2 million deaths worldwide per year, mainly due to cirrhosis and its complications. Oxidative stress plays an important role in the development of liver diseases. In order to maintain an adequate homeostasis, there must be a balance between free radicals and antioxidant mediators. Nuclear factor erythroid 2-related factor (Nrf2) and its negative regulator Kelch-like ECH-associated protein 1 (Keap1) comprise a defense mechanism against oxidative stress damage, and growing evidence considers this signaling pathway as a key pharmacological target for the treatment of liver diseases. In this review, we provide detailed and updated evidence regarding Nrf2 and its involvement in the development of the main liver diseases such as alcoholic liver damage, viral hepatitis, steatosis, steatohepatitis, cholestatic damage, and liver cancer. The molecular and cellular mechanisms of Nrf2 cellular signaling are elaborated, along with key and relevant antioxidant drugs, and mechanisms on how Keap1/Nrf2 modulation can positively affect the therapeutic response are described. Finally, exciting recent findings about epigenetic modifications and their link with regulation of Keap1/Nrf2 signaling are outlined.

In-silico drug repurposing study predicts the combination of pirfenidone and melatonin as a promising candidate therapy to reduce SARS-CoV-2 infection progression and respiratory distress caused by cytokine storm

From January 2020, COVID-19 is spreading around the world producing serious respiratory symptoms in infected patients that in some cases can be complicated by the severe acute respiratory syndrome, sepsis and septic shock, multiorgan failure, including acute kidney injury and cardiac injury. Cost and time efficient approaches to reduce the burthen of the disease are needed. To find potential COVID-19 treatments among the whole arsenal of existing drugs, we combined system biology and artificial intelligence-based approaches. The drug combination of pirfenidone and melatonin has been identified as a candidate treatment that may contribute to reduce the virus infection. Starting from different drug targets the effect of the drugs converges on human proteins with a known role in SARS-CoV-2 infection cycle. Simultaneously, GUILDify v2.0 web server has been used as an alternative method to corroborate the effect of pirfenidone and melatonin against the infection of SARS-CoV-2. We have also predicted a potential therapeutic effect of the drug combination over the respiratory associated pathology, thus tackling at the same time two important issues in COVID-19. These evidences, together with the fact that from a medical point of view both drugs are considered safe and can be combined with the current standard of care treatments for COVID-19 makes this combination very attractive for treating patients at stage II, non-severe symptomatic patients with the presence of virus and those patients who are at risk of developing severe pulmonary complications.

Dynamic High-Sensitivity Quantitation of Procollagen-I by Endogenous CRISPR-Cas9 NanoLuciferase Tagging

The ability to quantitate a protein of interest temporally and spatially at subcellular resolution in living cells would generate new opportunities for research and drug discovery, but remains a major technical challenge. Here, we describe dynamic, high-sensitivity protein quantitation technique using NanoLuciferase (NLuc) tagging, which is effective across microscopy and multiwell platforms. Using collagen as a test protein, the CRISPR-Cas9-mediated introduction of nluc (encoding NLuc) into the Col1a2 locus enabled the simplification and miniaturisation of procollagen-I (PC-I) quantitation. Collagen was chosen because of the clinical interest in its dysregulation in cardiovascular and musculoskeletal disorders, and in fibrosis, which is a confounding factor in 45% of deaths, including those brought about by cancer. Collagen is also the cargo protein of choice for studying protein secretion because of its unusual shape and size. However, the use of overexpression promoters (which drowns out endogenous regulatory mechanisms) is often needed to achieve good signal/noise ratios in fluorescence microscopy of tagged collagen. We show that endogenous knock-in of NLuc, combined with its high brightness, negates the need to use exogenous promoters, preserves the circadian regulation of collagen synthesis and the responsiveness to TGF-β, and enables time-lapse microscopy of intracellular transport compartments containing procollagen cargo. In conclusion, we demonstrate the utility of CRISPR-Cas9-mediated endogenous NLuc tagging to robustly quantitate extracellular, intracellular, and subcellular protein levels and localisation.

The effect of pirfenidone on rat chronic prostatitis/chronic pelvic pain syndrome and its mechanisms

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is an intractable problem of the urogenital system. The aetiopathogenesis and effective treatments for CP/CPPS are needed to be untangled. Pirfenidone is a molecule that exhibits anti-inflammatory, antifibrotic, and antioxidative stress capacities in a variety of animal experiments and clinical trials. This study was aimed to investigate the therapeutic effect of pirfenidone on CP/CPPS and to identify the mechanism responsible for it.

METHODS

A CP/CPPS model was induced in rats by intraprostatic injection of complete Freund's adjuvant (CFA). Blood and prostatic tissues were harvested for assessment after the administration of pirfenidone or vehicle for 4 weeks.

RESULTS

The findings revealed that pirfenidone significantly ameliorated chronic pelvic pain and inhibited prostatic inflammation and fibrosis. Further study found that pirfenidone suppressed the expression of proinflammatory mediators, including tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, IL-8. Pirfenidone exhibited a potent antioxidant capacity through improving the activities of glutathione, catalase, total superoxide dismutase, and reducing the production of malondialdehyde. Furthermore, pirfenidone also facilitated the polarization of M2 macrophages and suppressed the activation of the nuclear factor-κB (NF-κB) signaling pathway.

CONCLUSIONS

Pirfenidone can exert a beneficial effect against CFA-induced CP/CPPS by anti-inflammatory, antioxidative, antifibrotic properties, and the function is mediated at least partly through the M2 polarization of macrophages and the inhibition of NF-κB signaling pathway. These findings suggest that pirfenidone holds promise as a potential therapeutic for the treatment of CP/CPPS.

Oxygen for interstitial lung diseases

PURPOSE OF REVIEW

Supplemental oxygen therapy is prescribed for management of hypoxaemia in patients with interstitial lung disease (ILD). This review summarizes current evidence and implications of the use of supplemental oxygen therapy at home and during exercise training in ILD.

RECENT FINDINGS

Despite the significance of hypoxaemia in patients with ILD, there is a lack of high-quality evidence to guide the use of oxygen therapy in this population. Recent studies suggest that ambulatory oxygen may improve symptoms and health-related quality of life in patients with ILD. Long-term oxygen therapy for resting hypoxaemia in ILD is recommended by international guidelines. Supplemental oxygen during exercise may augment training effects, whereas therapeutic effects of nocturnal oxygen therapy are yet to be evaluated in patients with ILD. Nevertheless, it is important to consider the potential burden imposed by oxygen therapy on patients' daily activities of living.

SUMMARY

Ambulatory oxygen may be considered in ILD patients with exertional hypoxaemia, with long-term oxygen therapy being a standard care for resting hypoxaemia. Trials are currently underway to clarify therapeutic potentials of supplemental oxygen for exertional hypoxaemia and during exercise training in ILD patients, with additional research needed for the evaluation of nocturnal oxygen therapy.

Hepatoprotective Effect of Pericarpium zanthoxyli Extract Is Mediated via Antagonism of Oxidative Stress

Pericarpium zanthoxyli has been extensively used in traditional Oriental medicine to treat gastric disorders and has anti-inflammatory and antioxidative activities. Therefore, the present study examined a possible hepatoprotective effect of a P. zanthoxyli extract (PZE) and investigated the underlying molecular mechanisms. We employed an in vitro model of arachidonic acid (AA) + iron-induced hepatocyte damage and an in vivo model of CCl₄-induced liver injury to assess the effects of PZE and evaluated the relevant molecular targets using biochemical assays, flow cytometry analysis, Western blot, and histopathological analysis. The PZE inhibited AA + iron-induced hepatotoxicity in HepG2 cells, improved mitochondrial dysfunction, and reversed an increase in the cellular H₂O₂ production and a decrease in the reduced GSH levels induced by AA + iron. Treatment with either 30 or 100 μg/ml PZE significantly increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) protein, and the latter dose also increased the antioxidant response element- (ARE-) driven luciferase activity and enhanced the protein expressions of glutamate-cysteine ligase catalytic subunit and NAD(P)H:quinone oxidoreductase 1. In addition, treatment with 100 μg/ml PZE for 3 or 6 h increased the phosphorylation rates of Nrf2 and the extracellular signal-regulated kinase. In the in vivo experiment, oral treatment with both 100 and 300 mg/kg PZE inhibited the plasma aspartate aminotransferase activity, and the latter also inhibited the plasma alanine aminotransferase activity. In addition, both doses of PZE ameliorated the parenchymal degeneration and necrosis in the liver induced by CCl₄ administration, which was associated with reduced expressions of cleaved caspase-3, cleaved poly (ADP-ribose) polymerase, nitrotyrosine, and 4-hydroxynonenal by PZE. These findings suggest that PZE has protective effects against hepatotoxicity both in vitro and in vivo, which are mainly mediated via its antioxidant activity.

Pirfenidone anti-fibrotic effects are partially mediated by the inhibition of MUC1 bioactivation

Pirfenidone is a pleiotropic molecule approved to treat idiopathic pulmonary fibrosis (IPF). Pirfenidone has demonstrated to downregulate transforming growth factor-β1 (TGF-β1) cellular effects. However, its anti-fibrotic mechanism remains unclear. Here, we aim to analyze the effects of pirfenidone on the TGF-β1 canonical and non-canonical pathways, as well as, on the most characteristic IPF cellular processes. Results observed in this work showed that TGF-β1-induced canonical SMAD3 and non-canonical ERK1/2 phosphorylations were not inhibited by pirfenidone in alveolar A549 and lung fibroblasts MRC5 cells. In contrast, pirfenidone inhibited TGF-β1-induced MUC1-CT Thr⁴¹ (1224) and Tyr⁴⁶ (1229) phosphorylations, thus reducing the β-catenin activation. Additionally, immunoprecipitation and immunofluorescence studies in ATII cells and lung fibroblasts showed that pirfenidone inhibited the formation and nuclear translocation of the transcriptional fibrotic TGF-β1-induced phospho-SMAD3/MUC1-CT/active-β-catenin complex, and consequently the SMAD-binding element activation (SBE). This study provided also evidence of the inhibitory effect of pirfenidone on the TGF-β1-induced ATII to mesenchymal and fibroblast to myofibroblast transitions, fibroblast proliferation and ATII and fibroblast senescence. Therefore, it indicates that pirfenidone’s inhibitory effect on TGF-β1-induced fibrotic cellular processes is mediated by the inhibition of MUC1-CT phosphorylation, β-catenin activation, nuclear complex formation of phospho-SMAD3/MUC1-CT/active β-catenin and SBE activation, which may be of value to further develop anti-fibrotic IPF therapies.

Protective role of pirfenidone against experimentally-induced pancreatitis

BACKGROUND

Pirfenidone (PFD) is an orally active antifibrotic agent that has anti-inflammatory activity in diverse animal models. Its effect against acute pancreatitis (AP) has not been elucidated. Hence, the present investigation was carried out to assess the potential protective role of PFD against l-arginine-induced AP in mice.

METHODS

AP was induced in adult male Swiss albino mice via intraperitoneal injections of l-arginine (4 g/kg, twice each 1 h apart). PFD (250 mg/kg, orally) was administered one day before and on the day of l-arginine challenge. Twenty-four hours after l-arginine injection, the severity of AP was evaluated using biochemical and histological analyses. Indices of oxidative stress, inflammation and apoptosis were evaluated using ELISA and immunohistochemistry (IHC).

RESULTS

PFD suppressed the development of l-arginine-induced AP as revealed by the improvement of histopathological lesions of pancreatic specimen and the significant reduction of serum amylase and lipase levels. Notably, PFD reduced the lipid peroxidation and enhanced the antioxidants such as reduced glutathione (GSH) and superoxide dismutase (SOD) in pancreatic tissue. Importantly, PFD suppressed AP-associated elevation of inflammatory cytokines along with depression of nuclear factor kappa-B (NF-κB) immuno-expression in pancreatic tissue. Lastly, PFD efficiently ameliorated AP-induced elevation of the pro-apoptotic protein (Bax) and increased AP-induced reduction of the anti-apoptotic protein (Bcl2).

CONCLUSIONS

PFD protected against l-arginine-induced AP in mice through anti-oxidative, anti-inflammatory and anti-apoptotic properties.

Idiopathic Pulmonary Fibrosis and Lung Cancer: Mechanisms and Molecular Targets

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pulmonary disease with a median survival of 2–4 years after diagnosis. A significant number of IPF patients have risk factors, such as a history of smoking or concomitant emphysema, both of which can predispose the patient to lung cancer (LC) (mostly non-small cell lung cancer (NSCLC)). In fact, IPF itself increases the risk of LC development by 7% to 20%. In this regard, there are multiple common genetic, molecular, and cellular processes that connect lung fibrosis with LC, such as myofibroblast/mesenchymal transition, myofibroblast activation and uncontrolled proliferation, endoplasmic reticulum stress, alterations of growth factors expression, oxidative stress, and large genetic and epigenetic variations that can predispose the patient to develop IPF and LC. The current approved IPF therapies, pirfenidone and nintedanib, are also active in LC. In fact, nintedanib is approved as a second line treatment in NSCLC, and pirfenidone has shown anti-neoplastic effects in preclinical studies. In this review, we focus on the current knowledge on the mechanisms implicated in the development of LC in patients with IPF as well as in current IPF and LC-IPF candidate therapies based on novel molecular advances.

Combination Therapy with Pirfenidone plus Prednisolone Ameliorates Paraquat-Induced Pulmonary Fibrosis

Pirfenidone is known to slow the decline in vital capacity and increase survival in idiopathic pulmonary fibrosis (IPF). Besides, administration of glucocorticoids, e.g., prednisolone has been the conventional strategy to the treatment of patients with this disease, although their efficacy is under debate. Since multiple coactivated pathways are involved in the pathogenesis of IPF, combination therapy is a foundation strategy to cover many more synergetic mechanisms and increase response. The aim of the present study was to compare the therapeutic efficacy of prednisolone plus pirfenidone with pirfenidone alone in PQ-induced lung fibrosis. After development of PQ-induced lung fibrosis, pirfenidone, prednisolone, and their combination were administered for 14 consecutive days. Lung pathological lesions, along with increased hydroxyproline were determined in the paraquat group. Paraquat also caused oxidative stress and increasing the proinflammatory and profibrotic gene expression. Pirfenidone attenuated the PQ-induced pulmonary fibrosis from the analysis of antioxidant enzymes but prednisolone had no such effect. Co-treatment with pirfenidone and prednisolone suppressed lung hydroxyproline content, TGF-β1, and TNF-α; however, prednisolone alone could not suppress pulmonary fibrosis which was significantly suppressed only by pirfenidone. Pirfenidone also suppressed the increase in MMP-2 and TIMP-1 induced by PQ. All of these effects were exaggerated when pirfenidone coadministered with prednisolone. These findings suggest that pirfenidone exerts its antifibrotic effect through regulation of hydroxyproline content, oxidative stress and proinflammatory and profibrotic gene expression during the development of PQ-induced pulmonary fibrosis in rats and combination therapy with prednisolone can represent more potent therapeutic effects.

Fluorofenidone inhibits UV-A induced senescence in human dermal fibroblasts via the mammalian target of rapamycin-dependent SIRT1 pathway

The aim of this study was to investigate the protective effect of fluorofenidone (5‐methyl‐1‐[3‐fluorophenyl]‐2‐[1H]‐pyridone, AKF‐PD) on ultraviolet (UV)‐A‐induced senescence in human dermal fibroblasts (HDF) and examine the mechanisms involved. HDF were treated with AKF‐PD. Senescence‐associated (SA)‐β‐galactosidase level, cell viability and expression of p16 were evaluated. In addition, UV‐A‐irradiated HDF were treated with AKF‐PD, rapamycin and MHY1485; SA‐β‐galactosidase staining, 3‐(4 5‐dimethylthiazol‐2‐yl)‐2 5‐diphenyltetrazolium bromide assay and western blot for SIRT1 were performed; and phosphorylated mammalian target of rapamycin (p‐mTOR) expression and reactive oxygen species (ROS) levels were measured. Intracellular ROS was detected by the 2′,7′‐dichlorofluroescein diacetate probe. Our results showed that AKF‐PD substantially attenuated the changes of p16 expression, SA‐β‐galactosidase staining and cellular proliferation induced by UV‐A irradiation in HDF. AKF‐PD rescued the increased mTOR phosphorylation and reduced SIRT1 expression induced by UV‐A irradiation in HDF. AKF‐PD and rapamycin together had a synergistic effect on p‐mTOR reduction and SIRT1 increase. mTOR activator MHY1485 partly blocked the above effects. Moreover, intracellular ROS level induced by UV‐A irradiation could partly decrease by AKF‐PD, and MHY1485 could reduce this effect. Our results indicated that AKF‐PD could alleviate HDF senescence induced by UV‐A‐irradiation by inhibiting the p‐mTOR and increasing SIRT1. Moreover, AKF‐PD may be a potential treatment material for skin.

Pirfenidone protects against paraquat-induced lung injury and fibrosis in mice by modulation of inflammation, oxidative stress, and gene expression

In this study we investigated the protective effects and possible mechanisms of pirfenidone (PF) in paraquat (PQ)-induced lung injury and fibrosis in mice. Lung injury was induced by injection of PQ (20 mg/kg). Thereafter, mice orally received water and PF (100 and 200 mg/kg) for four weeks. After 28 days, the inflammation and fibrosis were determined in the lungs by analysis of histopathology, bronchoalveolar lavage fluid (BALF) cell count, lung wet/dry weight ratio, hydroxyproline content, and oxidative stress biomarkers. Expression of several genes involved in fibrogenesis and modulation of reactive oxygen species (ROS) production, such as TGF-β1, α-SMA, collagen Iα and IV, NOX1, NOX4, iNOS, and GPX1 were determined using RT-qPCR. PF significantly decreased the lung fibrosis and edema, inflammatory cells infiltration, TGF-β1 concentration, and amount of hydroxyproline in the lung tissue. PF dose-dependently improved the expression level of the studied genes to the near normal. Decreasing of lung lipid peroxidation and catalase activity, and increasing of SOD activity in the treated mice were significant compared to the control group. Pirfenidone ameliorate paraquat induced lung injury and fibrosis partly through inhibition of inflammation and oxidative stress, and downregulation of genes encoding for profibrotic cytokines and enzymatic systems for ROS production.

Effects of pirfenidone in acute and sub-chronic liver fibrosis, and an initiation-promotion cancer model in the mouse

Liver fibrosis results from chronic tissue damage and excessive regeneration with accumulation of extracellular matrix proteins; it is a precursor of liver cirrhosis and hepatocellular carcinoma. Liver fibrosis treatments are primarily directed at inflammation, with few options to combat fibrogenesis. Pirfenidone is a drug approved for idiopathic pulmonary fibrosis and this study was focused on anti-fibrotic and anti-cancer potential of pirfenidone in the liver of male B6C3F1/J mice. In a dose-finding study, mice were treated with CCl₄ (0.2ml/kg ip, 2×wk for 4weeks) while on a pirfenidone-containing (0-600mg/kg) diet. Pirfenidone at doses of 300 and 600mg/kg had significant anti-fibrotic (collagen) and anti-inflammatory (serum transaminases and "ballooning" hepatocyte) effects. In a sub-chronic study (14weeks), mice received CCl₄ while on pirfenidone (300mg/kg) diet. Pirfenidone significantly reduced collagen deposition, but had little effect of inflammation and injury. In an initiation-promotion cancer study with N-nitrosodiethylamine and CCl₄, pirfenidone (300mg/kg) did not affect incidence, size, or multiplicity of liver tumors. Overall, we conclude that while pirfenidone exhibits strong anti-fibrotic effects in early stage liver fibrosis, it is less effective in advanced liver fibrosis and was not protective in an initiation-promotion liver cancer.

Tissue metabolic changes for effects of pirfenidone in rats of acute paraquat poisoning by GC-MS

We developed a metabolomic method to evaluate the effect of pirfenidone on rats with acute paraquat (PQ) poisoning, through the analysis of various tissues (lung, liver, kidney, and heart), by gas chromatography–mass spectrometry (GC-MS). Thirty-eight rats were randomly divided into a control group, an acute PQ (20 mg kg−1) poisoning group, a pirfenidone (20 mg kg−1) treatment group, and a pirfenidone (40 mg kg−1) treatment group. Partial least squares-discriminate analysis (PLS-DA) revealed metabolic alterations in rat tissue samples from the two pirfenidone treatment groups after acute PQ poisoning. The PLS-DA 3D score chart showed that the rats in the acute PQ poisoning group were clearly distinguished from the rats in the control group. Also, the two pirfenidone treatment groups were distinguished from the acute PQ poisoning group and control group. Additionally, the pirfenidone (40 mg kg−1) treatment group was separated farther than the pirfenidone (20 mg kg−1) treatment group from the acute PQ poisoning group. Evaluation of the pathological changes in the rat tissues revealed that treatment with pirfenidone appeared to decrease pulmonary fibrosis in the acute PQ poisoning rats. The results indicate that pirfenidone induced beneficial metabolic alterations in the tissues of rats with acute PQ poisoning. Rats with acute PQ poisoning exhibited a certain reduction in biochemical indicators after treatment with pirfenidone, indicating that pirfenidone could protect liver and kidney function. Accordingly, the developed metabolomic approach proved to be useful to elucidate the effect of pirfenidone in rats of acute PQ poisoning.

Anti-TNFα therapy in inflammatory lung diseases

Increased levels of tumor necrosis factor (TNF) α have been linked to a number of pulmonary inflammatory diseases including asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), sarcoidosis, and interstitial pulmonary fibrosis (IPF). TNFα plays multiple roles in disease pathology by inducing an accumulation of inflammatory cells, stimulating the generation of inflammatory mediators, and causing oxidative and nitrosative stress, airway hyperresponsiveness and tissue remodeling. TNFα-targeting biologics, therefore, present a potentially highly efficacious treatment option. This review summarizes current knowledge on the role of TNFα in pulmonary disease pathologies, with a focus on the therapeutic potential of TNFα-targeting agents in treating inflammatory lung diseases.

Phenylpyrrolidine structural mimics of pirfenidone lacking antifibrotic activity: A new tool for mechanism of action studies

Pirfenidone recently received FDA approval as one of the first two drugs designed to treat idiopathic pulmonary fibrosis. While the clinical data continues to support the efficacy of pirfenidone, the specific molecular mechanism of action of this drug has not been fully defined. From a chemical perspective the comparatively simple and lipophilic structure of pirfenidone combined with its administration at high doses, both experimentally and clinically, complicates some of the basic tenants of drug action and drug design. Our objective here was to identify a commercially available structural mimic of pirfenidone which retains key aspects of its physical chemical properties but does not display any of its antifibrotic effects. We tested these molecules using lung fibroblasts derived from patients with idiopathic pulmonary fibrosis and found phenylpyrrolidine based analogs of pirfenidone that were non-toxic and lacked antifibrotic activity even when applied at millimolar concentrations. Based on our findings, these molecules represent pharmacological tools for future studies delineating pirfenidone's mechanism of action.

Antifibrotic effect of pirfenidone in a mouse model of human nonalcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is characterized by steatosis with lobular inflammation and hepatocyte injury. Pirfenidone (PFD) is an orally bioavailable pyridone derivative that has been clinically used for the treatment of idiopathic pulmonary fibrosis. However, it remains unknown whether PFD improves liver fibrosis in a mouse model with human NASH-like phenotypes. In this study, we employed melanocortin 4 receptor-deficient (MC4R-KO) mice as a mouse model with human NASH-like phenotypes to elucidate the effect and action mechanisms of PFD on the development of NASH. PFD markedly attenuated liver fibrosis in western diet (WD)-fed MC4R-KO mice without affecting metabolic profiles or steatosis. PFD prevented liver injury and fibrosis associated with decreased apoptosis of liver cells in WD-fed MC4R-KO mice. Pretreatment of PFD inhibited the tumor necrosis factor-α (TNF-α)-induced liver injury and fibrogenic responses associated with decreased apoptosis of liver cells in wild-type mice. PFD also prevented TNF-α-induced hepatocyte apoptosis in vitro with reduced activation of caspase-8 and -3. This study provides evidence for the antifibrotic effect of PFD in a mouse model of human NASH. The data of this study highlight hepatocyte apoptosis as a potential therapeutic target, and suggest that PFD can be repositioned as an antifibrotic drug for human NASH.

Pirfenidone ameliorates concanavalin A-induced hepatitis in mice via modulation of reactive oxygen species/nuclear factor kappa B signalling pathways

Objectives

This study aimed to evaluate the potential protective effects of pirfenidone (PFD) against concanavalin A (Con A)-induced hepatitis in mice.

Methods

Autoimmune model of hepatitis was established using single intravenous injection of Con A. Mice were randomly assigned into four groups as follows: control group; Con A group; and two groups, receiving PFD in two dose levels (200, 300 mg/kg) for 5 days before Con A administration. Extent of hepatitis was studied using biochemical, histopathological and immunohistochemical estimations.

Key findings

Hepatitis was clearly evident through extensive hepatocellular lesions and elevated levels of serum transaminases, alkaline phosphatase and lactate dehydrogenase. Con A induced an imbalance between oxidant and antioxidant status in the hepatic tissue. Furthermore, Con A significantly elevated hepatic nuclear factor kappa B (NF-κB) expression and inflammatory cytokines levels (tumour necrosis factor-alpha, interleukin-6 and nitric oxide). PFD pretreatment potently ameliorated all these pathological changes.

Conclusions

Pirfenidone hepatoprotective activity may be mediated through its antioxidant ability that suppresses NF-κB activation signalling pathways suggesting that PFD may be a new candidate for treatment of acute hepatitis.

Effect of Pirfenidone on Vascular Proliferation, Inflammation and Fibrosis in an Abdominal Adhesion Rat Model

AIM

To study the efficacy of pirfenidone for prevention of postoperative adhesion formation in an adhesion rat model.

MATERIALS AND METHODS

Eighteen female Wistar rats were subjected to right-sided parietal peritoneum and right uterine horn adhesion model. Rats were randomized into three groups: group 1 (control) (closure of midline abdominal incision without any agent administration), group 2 (closure of incision after intraperitoneal administration of pirfenidone), and group 3 (closure of incision and only oral administration of pirfenidone for 14 days). Relaparotomy was performed 14 days after the first surgery. Effect of pirfenidone on adhesion formation was assessed on light microscopy by scoring vascular proliferation, inflammation, fibrosis, and collagen formation in the scarred tissue. Effect of pirfenidone on inflammation was assessed by measurement of transforming growth factor-β and interleukin-17 levels in scarred tissue.

RESULTS

The degree of vascular proliferation (1.32 ± 0.39 versus 2.34 ± 0.46, p < 0.001), inflammation (1.60 ± 0.70 versus 2.60 ± 0.52, p < 0.01), and fibrosis (1.50 ± 0.53 versus 2.40 ± 0.52, p < 0.01) were less prominent in group 2 compared to group 1, respectively. Only vascular proliferation was found to be less prominent in group 3 compared to group 1 (1.60 ± 0.42 versus 2.34 ± 0.46, p < 0.01). Intraperitoneal and oral administration of pirfenidone reduced tissue levels of inflammatory markers (TGF-β and IL-17) in parietal and visceral peritoneum compared to control group. Intraperitoneal administration of pirfenidone compared to oral administration was more effective in reducing tissue levels of inflammatory markers.

CONCLUSION

Pirfenidone is an effective agent on the prevention of postoperative vascular proliferation, inflammation and fibrosis in scarred tissue particularly with intraperitoneal administration.

Hepatoprotective and Anti-fibrotic Agents: It's Time to Take the Next Step

Hepatic fibrosis and cirrhosis cause strong human suffering and necessitate a monetary burden worldwide. Therefore, there is an urgent need for the development of therapies. Pre-clinical animal models are indispensable in the drug discovery and development of new anti-fibrotic compounds and are immensely valuable for understanding and proofing the mode of their proposed action. In fibrosis research, inbreed mice and rats are by far the most used species for testing drug efficacy. During the last decades, several hundred or even a thousand different drugs that reproducibly evolve beneficial effects on liver health in respective disease models were identified. However, there are only a few compounds (e.g., GR-MD-02, GM-CT-01) that were translated from bench to bedside. In contrast, the large number of drugs successfully tested in animal studies is repeatedly tested over and over engender findings with similar or identical outcome. This circumstance undermines the 3R (Replacement, Refinement, Reduction) principle of Russell and Burch that was introduced to minimize the suffering of laboratory animals. This ethical framework, however, represents the basis of the new animal welfare regulations in the member states of the European Union. Consequently, the legal authorities in the different countries are halted to foreclose testing of drugs in animals that were successfully tested before. This review provides a synopsis on anti-fibrotic compounds that were tested in classical rodent models. Their mode of action, potential sources and the observed beneficial effects on liver health are discussed. This review attempts to provide a reference compilation for all those involved in the testing of drugs or in the design of new clinical trials targeting hepatic fibrosis.

XL413, a cell division cycle 7 kinase inhibitor enhanced the anti-fibrotic effect of pirfenidone on TGF-β1-stimulated C3H10T1/2 cells via Smad2/4

Pirfenidone is an orally bioavailable synthetic compound with therapeutic potential for idiopathic pulmonary fibrosis. It is thought to act through antioxidant and anti-fibrotic pathways. Pirfenidone inhibits proliferation and/or myofibroblast differentiation of a wide range of cell types, however, little studies have analyzed the effect of pirfenidone on the mesenchymal stem cells, which play an important role on the origin of myofibroblasts. We recently found that pirfenidone had anti-proliferative activity via G1 phase arrest and cell division cycle 7 (Cdc7) kinase expression decrease in transforming growth factor-β1 (TGF-β1)-stimulated murine mesenchymal stem C3H10T1/2 cells. Pirfenidone also had inhibiting effect on the migration and α-SMA expression. Moreover, in this study we showed for the first time that Cdc7 inhibitor XL413 enhanced the anti-fibrotic activity of pirfenidone via depressed the expression of Smad2/4 proteins, and also prevented the nuclear accumulation and translocation of Smad2 protein. In conclusion, we demonstrated that pirfenidone inhibited proliferation, migration and differentiation of TGF-β1-stimulated C3H10T1/2 cells, which could be enhanced by Cdc7 inhibitor XL413, via Smad2/4. Combination with pirfenidone and XL413 might provide a potential candidate for the treatment of TGF-β1 associated fibrosis. It needs in vivo studies to further validate its therapeutic function and safety in the future.

Role and New Insights of Pirfenidone in Fibrotic Diseases

Pirfenidone (PFD) is a non-peptide synthetic molecule issued as a broad-spectrum anti-fibrotic drug with the ability to decrease TGF-β1, TNF-α, PDGF and COL1A1 expression, which is highly related to prevent or remove excessive deposition of scar tissue in several organs. Basic and clinical evidence suggests that PFD may safely slow or inhibit the progressive fibrosis swelling after tissue injuries. Furthermore, a number of evidence suggests that this molecule will have positive effects in the treatment of other inflammatory diseases. This review contains current research in which PFD has been used as the treatment of several diseases, and focus mainly in the outcomes related to improve inflammation and fibrogenesis. Therefore, the main goal of this review is to focus on the novel findings of PFD efficacy rather than deepen in the chemical aspects of the molecule.

Inflammatory response mechanisms exacerbating hypoxemia in coexistent pulmonary fibrosis and sleep apnea

Mediators of inflammation, oxidative stress, and chemoattractants drive the hypoxemic mechanisms that accompany pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis commonly have obstructive sleep apnea, which potentiates the hypoxic stimuli for oxidative stress, culminating in systemic inflammation and generalized vascular endothelial damage. Comorbidities like pulmonary hypertension, obesity, gastroesophageal reflux disease, and hypoxic pulmonary vasoconstriction contribute to chronic hypoxemia leading to the release of proinflammatory cytokines that may propagate clinical deterioration and alter the pulmonary fibrotic pathway. Tissue inhibitor of metalloproteinase (TIMP-1), interleukin- (IL-) 1α, cytokine-induced neutrophil chemoattractant (CINC-1, CINC-2α/β), lipopolysaccharide induced CXC chemokine (LIX), monokine induced by gamma interferon (MIG-1), macrophage inflammatory protein- (MIP-) 1α, MIP-3α, and nuclear factor- (NF-) κB appear to mediate disease progression. Adipocytes may induce hypoxia inducible factor (HIF) 1α production; GERD is associated with increased levels of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and tumor necrosis factor alpha (TNF-α); pulmonary artery myocytes often exhibit increased cytosolic free Ca2+. Protein kinase C (PKC) mediated upregulation of TNF-α and IL-1β also occurs in the pulmonary arteries. Increased understanding of the inflammatory mechanisms driving hypoxemia in pulmonary fibrosis and obstructive sleep apnea may potentiate the identification of appropriate therapeutic targets for developing effective therapies.

Isoliquiritigenin attenuates oxidative hepatic damage induced by carbon tetrachloride with or without buthionine sulfoximine

Glycyrrhizae radix (G. radix) has been demonstrated to have hepatoprotective properties. This study determined the therapeutic effects of isoliquiritigenin (isoLQ) in G. radix, against liver injury induced by CCl4 in rats. CCl4 (0.5 ml/kg/d, twice) or CCl4 plus buthionine sulfoximine exerted severe liver damage assessed by increased plasma levels of alanine aminotransferase and aspartate aminotransferase, in addition to hepatic degeneration and necrosis. These pathological changes were markedly protected by pretreatment with isoLQ (5, 20 mg/kg/d, p.o.) for 3 consecutive days. In addition, pretreatment with isoLQ inhibited CCl4-induced reduction of cytochrome P450 2E1 protein and mRNA expression as well as activity in the liver. Moreover, isoLQ pretreatment reversed the decrease in hepatic antioxidant capacity induced by CCl4 as well as suppressed expression of tumor necrosis factor-alpha and cyclooxigenase-2 in the liver. These results suggest that isoLQ has a protective effect against CCl4-induced liver damage through induction of antioxidant and anti-inflammatory activities.

Renoprotective mechanisms of pirfenidone in hypertension-induced renal injury: through anti-fibrotic and anti-oxidative stress pathways

Pirfenidone (PFD) is a novel anti-fibrotic agent that targets TGFβ. However, the mechanisms underlying its renoprotective properties in hypertension-induced renal injury are poorly understood. We investigated the renoprotective properties of PFD and clarified its renoprotective mechanisms in a rat hypertension-induced renal injury model. Dahl salt-sensitive rats were fed a high-salt diet with or without 1% PFD for 6 weeks. During the administration period, we examined the effects of PFD on blood pressure and renal function. After the administration, the protein levels of renal TGFβ, Smad2/3, TNFα, MMP9, TIMP1, and catalase were examined. In addition, total serum antioxidant activity was measured. Compared to untreated rats, PFD treatment significantly attenuated blood pressure and proteinuria. Histological study showed that PFD treatment improved renal fibrosis. PFD may exert its anti-fibrotic effects via the downregulation of TGFβ-Smad2/3 signaling, improvement of MMP9/TIMP1 balance, and suppression of fibroblast proliferation. PFD treatment also increased catalase expression and total serum antioxidant activity. In contrast, PFD treatment did not affect the expression of TNFα protein, macrophage or T-cell infiltration, or plasma interleukin 1β levels. PFD prevents renal injury via its anti-fibrotic and anti-oxidative stress mechanisms. Clarifying the renoprotective mechanisms of PFD will help improve treatment for chronic renal diseases.

Treatment with pirfenidone for two years decreases fibrosis, cytokine levels and enhances CB2 gene expression in patients with chronic hepatitis C

BACKGROUND

The aim of this study was to assess whether two-years treatment with Pirfenidone influences necroinflammation, fibrosis and steatosis, serum levels of TGF-β1, IL-6, TNF-α and CB1 and CB2 gene expression, in patients with chronic hepatitis C (CHC).

METHODS

Twenty-eight patients out of 34 with CHC virus infection were enrolled in the study and received Pirfenidone (1200 mg/day) for 24 months. Six patients dropped out after 12 months of PFD. Liver biopsies and serum samples were obtained at the beginning and end of treatment. Modified HAI was calculated. CB1 and CB2 gene expression was correlated with fibrosis progression alongside with necroinflammation and steatosis. TGF-β1, IL-6, TNF-α and liver transaminases were measured in serum at two-months intervals. HCV genotype and viral load were also assessed. Quality of life was evaluated by SF36 questionnaires and the prognosis of disease was assessed with Child-Pugh score. The Wilcoxon test matched-pair signed ranks were used to analyze the outcomes.

RESULTS

Intention to treat analyses were performed for biochemistry and clinical parameters. At the end of treatment, necroinflammation grading was reduced in an average of 3.2 points in 82% of patients (p < 0.05) and Ishak's fibrosis stage decreased 2-points average in 67% of patients (p < 0.05). Steatosis decreased in 61% of patients. IL-6 and TGF-β1 serum levels decreased significantly in 93% and 67% of patients (p < 0.05), respectively, while TNF-α diminished in 47% of patients. ALT and AST tended to normalize in 81% of patients; CB2 mRNA levels increased in 86% and CB1 expression diminished in 29% of patients. Both, quality of life and Child-Pugh score improvements were reported in all patients.

CONCLUSIONS

Pirfenidone for two years benefits CHC patients and improves inflammation, fibrosis and steatosis in higher number of patients as previously shown for 12-months treatment with PFD. Additionally, PFD improved TGFβ1 and IL-6 levels and diminished liver expression of anti-fibrogenic receptor CB2.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02161952. Protocol Registration Date: 06/11/2014.

Functional and structural impact of pirfenidone on the alterations of cardiac disease and diabetes mellitus

A synthetic compound, termed pirfenidone (PFD), is considered promising for the treatment of cardiac disease. It leads to beneficial effects in animal models of diabetes mellitus (DM); as well as in heart attack, atrial fibrillation, muscular dystrophy, and diabetic cardiomyopathy (DC). The latter is a result of alterations linked to metabolic syndrome as they promote cardiac hypertrophy, fibrosis and contractile dysfunction. Although reduced level of fibrosis and stiffness represent an essential step in the mechanism of PFD action, a wide range of functional effects might also contribute to the therapeutic benefits. For example, PFD stimulates L-type voltage-gated Ca(2+) channels (LTCCs), which are pivotal for a process known as excitation-contraction coupling (ECC). Recent evidence suggests that these two types of actions - namely structural and functional - aid in treating both cardiac disease and DM. This view is supported by the fact that in DC, for example, systolic dysfunction arises from both cardiac stiffness linked to fibrosis and down-regulation of ECC. Thus, not surprisingly, clinical trials have been conducted with PFD in the settings of DM, for treating not only cardiac but also renal disease. This review presents all these concepts, along with the possible mechanisms and pathophysiological consequences.

Management of fibrosis: the mesenchymal stromal cells breakthrough

Fibrosis is the endpoint of many chronic inflammatory diseases and is defined by an abnormal accumulation of extracellular matrix components. Despite its slow progression, it leads to organ malfunction. Fibrosis can affect almost any tissue. Due to its high frequency, in particular in the heart, lungs, liver, and kidneys, many studies have been conducted to find satisfactory treatments. Despite these efforts, current fibrosis management therapies either are insufficiently effective or induce severe adverse effects. In the light of these facts, innovative experimental therapies are being investigated. Among these, cell therapy is regarded as one of the best candidates. In particular, mesenchymal stromal cells (MSCs) have great potential in the treatment of inflammatory diseases. The value of their immunomodulatory effects and their ability to act on profibrotic factors such as oxidative stress, hypoxia, and the transforming growth factor-β1 pathway has already been highlighted in preclinical and clinical studies. Furthermore, their propensity to act depending on the microenvironment surrounding them enhances their curative properties. In this paper, we review a large range of studies addressing the use of MSCs in the treatment of fibrotic diseases. The results reported here suggest that MSCs have antifibrotic potential for several organs.

The effect of antifibrotic drugs in rat precision-cut fibrotic liver slices

Two important signaling pathways in liver fibrosis are the PDGF- and TGFβ pathway and compounds inhibiting these pathways are currently developed as antifibrotic drugs. Testing antifibrotic drugs requires large numbers of animal experiments with high discomfort. Therefore, a method to study these drugs ex vivo was developed using precision-cut liver slices from fibrotic rat livers (fPCLS), representing an ex vivo model with a multicellular fibrotic environment. We characterized the fibrotic process in fPCLS from rat livers after 3 weeks of bile duct ligation (BDL) during incubation and tested compounds predominantly inhibiting the TGFβ pathway (perindopril, valproic acid, rosmarinic acid, tetrandrine and pirfenidone) and PDGF pathway (imatinib, sorafenib and sunitinib). Gene expression of heat shock protein 47 (Hsp47), α smooth muscle actin (αSma) and pro-collagen 1A1 (Pcol1A1) and protein expression of collagens were determined. During 48 hours of incubation, the fibrosis process continued in control fPCLS as judged by the increased gene expression of the three fibrosis markers, and the protein expression of collagen 1, mature fibrillar collagen and total collagen. Most PDGF-inhibitors and TGFβ-inhibitors significantly inhibited the increase in gene expression of Hsp47, αSma and Pcol1A1. Protein expression of collagen 1 was significantly reduced by all PDGF-inhibitors and TGFβ-inhibitors, while total collagen was decreased by rosmarinic acid and tetrandrine only. However, fibrillar collagen expression was not changed by any of the drugs. In conclusion, rat fPCLS can be used as a functional ex vivo model of established liver fibrosis to test antifibrotic compounds inhibiting the PDGF- and TGFβ signalling pathway.

Nrf2 and Snail-1 in the prevention of experimental liver fibrosis by caffeine

AIM: To determine the molecular mechanisms involved in experimental hepatic fibrosis prevention by caffeine (CFA).

METHODS: Liver fibrosis was induced in Wistar rats by intraperitoneal thioacetamide or bile duct ligation and they were concomitantly treated with CFA (15 mg/kg per day). Fibrosis and inflammatory cell infiltrate were evaluated and classified by Knodell index. Inflammatory infiltrate was quantified by immunohistochemistry (anti-CD11b). Gene expression was analyzed by quantitative reverse transcription-polymerase chain reaction for collagen I (Col-1), connective tissue growth factor (CTGF), transforming growth factor β1 (TGF-β1), tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1), IL-6, superoxide dismutase (SOD) and catalase (CAT). Activation of Nrf2 and Snail-1 was analyzed by Western-blot. TNF-α expression was proved by enzyme-linked immunosorbant assay, CAT activity was performed by zymography.

RESULTS: CFA treatment diminished fibrosis index in treated animals. The Knodell index showed both lower fibrosis and necroinflammation. Expression of profibrogenic genes CTGF, Col-1 and TGF-β1 and proinflammatory genes TNF-α, IL-6 and IL-1 was substantially diminished with CFA treatment with less CD11b positive areas. Significantly lower values of transcriptional factor Snail-1 were detected in CFA treated rats compared with cirrhotic rats without treatment; in contrast Nrf2 was increased in the presence of CFA. Expression of SOD and CAT was greater in animals treated with CFA showing a strong correlation between mRNA expression and enzyme activity.

CONCLUSION: Our results suggest that CFA inhibits the transcriptional factor Snail-1, down-regulating profibrogenic genes, and activates Nrf2 inducing antioxidant enzymes system, preventing inflammation and fibrosis.

Iron laden macrophages in idiopathic pulmonary fibrosis: the telltale of occult alveolar hemorrhage?

RATIONALE

A number of observations suggest that iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (IPF) with vascular abnormalities, including pulmonary hypertension.

OBJECTIVES

The aim of this study was to determine the prevalence and intensity of accumulation of alveolar epithelial lining fluid (ELF) iron and of alveolar macrophage hemosiderin in IPF and its relationship with disease severity.

METHODS

Forty seven IPF patients and 14 healthy controls were retrospectively evaluated for iron accumulation in the lower respiratory tract using total iron spectrophotometric measures and for hemosiderin accumulation using the Perls' stain with the Golde score.

MEASUREMENTS AND MAIN RESULTS

Total iron levels in ELF were significantly increased in IPF patients compared to non-smoking controls (p < 0.05); there were no differences with healthy smokers (p = 0.2). Hemosiderin accumulation in alveolar macrophages was similar in never smoking and ever smoking IPF patients (p = 0.5), was significantly higher in IPF patients than in both smoking and non-smoking healthy controls (p < 0.05, all comparisons) and was positively correlated with echocardiographic estimates of pulmonary artery systolic pressure (p < 0.05) and with increasing disease severity scores (p < 0.05).

CONCLUSIONS

The data show exaggerated accumulation of iron in IPF broncho-alveolar ELF and alveolar cells with no association with tobacco smoke, thus suggesting, occult pulmonary hemorrhage as a likely cause.