Atorvastatin attenuates bleomycin-induced pulmonary fibrosis via suppressing iNOS expression and the CTGF (CCN2)/ERK signaling pathway

Rosuvastatin attenuates airway inflammation and remodeling in a chronic allergic asthma model through modulation of the AMPKα signaling pathway

The efficacy of rosuvastatin in reducing allergic inflammation has been established. However, its potential to reduce airway remodeling has yet to be explored. This study aimed to evaluate the efficacy of rosuvastatin in reducing airway inflammation and remodeling in a mouse model of chronic allergic asthma induced by sensitization and challenge with OVA. Histology of the lung tissue and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) showed a marked decrease in airway inflammation and remodeling in mice treated with rosuvastatin, as evidenced by a decrease in goblet cell hyperplasia, collagen deposition, and smooth muscle hypertrophy. Furthermore, levels of inflammatory cytokines, angiogenesis-related factors, and OVA-specific IgE in BALF, plasma, and serum were all reduced upon treatment with rosuvastatin. Western blotting was employed to detect AMPK expression, while immunohistochemistry staining was used to observe the expression of remodeling signaling proteins such as α-SMA, TGF-β, MMP-9, and p-AMPKα in the lungs. It was found that the activity of 5'-adenosine monophosphate-activated protein kinase alpha (AMPKα) was significantly lower in the lungs of OVA-induced asthmatic mice compared to Control mice. However, the administration of rosuvastatin increased the ratio of phosphorylated AMPK to total AMPKα, thus inhibiting the formation of new blood vessels, as indicated by CD31-positive staining mainly in the sub-epithelial region. These results indicate that rosuvastatin can effectively reduce airway inflammation and remodeling in mice with chronic allergic asthma caused by OVA, likely due to the reactivation of AMPKα and a decrease in angiogenesis.

Identification of endophenotypes supporting outcome prediction in hemodialysis patients based on mechanistic markers of statin treatment

Background

Statins are widely used to reduce the risk of cardiovascular disease (CVD). Patients with end-stage renal disease (ESRD) on hemodialysis have significantly increased risk of developing CVD. Statin treatment in these patients however did not show a statistically significant benefit in large trials on a patient cohort level.

Methods

We generated gene expression profiles for statins to investigate the impact on cellular programs in human renal proximal tubular cells and mesangial cells in-vitro. We subsequently selected biomarkers from key statin-affected molecular pathways and assessed these biomarkers in plasma samples from the AURORA cohort, a double-blind, randomized, multi-center study of patients on hemodialysis or hemofiltration that have been treated with rosuvastatin. Patient clusters (phenotypes) were created based on the identified biomarkers using Latent Class Model clustering and the associations with outcome for the generated phenotypes were assessed using Cox proportional hazards regression models. The multivariable models were adjusted for clinical and biological covariates based on previously published data in AURORA.

Results

The impact of statin treatment on mesangial cells was larger as compared with tubular cells with a large overlap of differentially expressed genes identified for atorvastatin and rosuvastatin indicating a predominant drug class effect. Affected molecular pathways included TGFB-, TNF-, and MAPK-signaling and focal adhesion among others. Four patient clusters were identified based on the baseline plasma concentrations of the eight biomarkers. Phenotype 1 was characterized by low to medium levels of the hepatocyte growth factor (HGF) and high levels of interleukin 6 (IL6) or matrix metalloproteinase 2 (MMP2) and it was significantly associated with outcome showing increased risk of developing major adverse cardiovascular events (MACE) or cardiovascular death. Phenotype 2 had high HGF but low Fas cell surface death receptor (FAS) levels and it was associated with significantly better outcome at 1 year.

Conclusions

In this translational study, we identified patient subgroups based on mechanistic markers of statin therapy that are associated with disease outcome in patients on hemodialysis.

Drugs targeting CTGF in the treatment of pulmonary fibrosis

Pulmonary fibrosis represents the final alteration seen in a wide variety of lung disorders characterized by increased fibroblast activity and the accumulation of substantial amounts of extracellular matrix, along with inflammatory damage and the breakdown of tissue architecture. This condition is marked by a significant mortality rate and a lack of effective treatments. The depositing of an excessive quantity of extracellular matrix protein follows the damage to lung capillaries and alveolar epithelial cells, leading to pulmonary fibrosis and irreversible damage to lung function. It has been proposed that the connective tissue growth factor (CTGF) plays a critical role in the advancement of pulmonary fibrosis by enhancing the accumulation of the extracellular matrix and exacerbating fibrosis. In this context, the significance of CTGF in pulmonary fibrosis is examined, and a summary of the development of drugs targeting CTGF for the treatment of pulmonary fibrosis is provided.

Association between statin use and the risk for idiopathic pulmonary fibrosis and its prognosis: a nationwide, population-based study

Given the pleiotropic effects of statins beyond their lipid-lowering effects, there have been attempts to evaluate the role of statin therapy in IPF, but they have shown inconclusive results. Data from the National Health Insurance Service (NHIS) database of South Korea were used to investigate the effects of statin therapy on IPF. The IPF cohort consisted of a total of 10,568 patients who were newly diagnosed with IPF between 2010 and 2017. These patients were then matched in a 1:3 ratio to 31,704 subjects from a control cohort without IPF, with matching based on age and sex. A case-control study was performed to evaluate the association between statin use and the risk for IPF, and the multivariable analysis revealed that statin use was associated with a lower risk for IPF (adjusted OR 0.847, 95% CI 0.800-0.898). Using the IPF cohort, we also evaluated whether statin use at the time of diagnosis was associated with future clinical outcomes. The statin use at the time of IPF diagnosis was associated with improved overall survival (adjusted HR 0.779, 95% CI 0.709-0.856). Further prospective studies are needed to clarify the role of statin therapy in IPF.

Comprehensive review of potential drugs with anti-pulmonary fibrosis properties

Pulmonary fibrosis is a chronic and progressive lung disease characterized by the accumulation of scar tissue in the lungs, which leads to impaired lung function and reduced quality of life. The prognosis for idiopathic pulmonary fibrosis (IPF), which is the most common form of pulmonary fibrosis, is generally poor. The median survival for patients with IPF is estimated to be around 3-5 years from the time of diagnosis. Currently, there are two approved drugs (Pirfenidone and Nintedanib) for the treatment of IPF. However, Pirfenidone and Nintedanib are not able to reverse or cure pulmonary fibrosis. There is a need for new pharmacological interventions that can slow or halt disease progression and cure pulmonary fibrosis. This review aims to provide an updated overview of current and future drug interventions for idiopathic pulmonary fibrosis, and to summarize possible targets of potential anti-pulmonary fibrosis drugs, providing theoretical support for further clinical combination therapy or the development of new drugs.

Therapeutic strategies to target connective tissue growth factor in fibrotic lung diseases

The treatment of interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF), remains challenging as current available antifibrotic agents are not effective in halting disease progression. Connective tissue growth factor (CTGF), also known as cellular communication factor 2 (CCN2), is a member of the CCN family of proteins that regulates cell signaling through cell surface receptors such as integrins, the activity of cytokines/growth factors, and the turnover of extracellular matrix (ECM) proteins. Accumulating evidence indicates that CTGF plays a crucial role in promoting lung fibrosis through multiple processes, including inducing transdifferentiation of fibroblasts to myofibroblasts, epithelial-mesenchymal transition (EMT), and cooperating with other fibrotic mediators such as TGF-β. Increased expression of CTGF has been observed in fibrotic lungs and inhibiting CTGF signaling has been shown to suppress lung fibrosis in several animal models. Thus, the CTGF signaling pathway is emerging as a potential therapeutic target in IPF and other pulmonary fibrotic conditions. This review provides a comprehensive overview of the current evidence on the pathogenic role of CTGF in pulmonary fibrosis and discusses the current therapeutic agents targeting CTGF using a systematic review approach.

Anti-fibrotic effects of statin drugs: a review of evidence and mechanisms

Fibrosis is a pathological repair process common among organs, that responds to damage by replacement of tissue with non-functional connective tissue. Despite the widespread prevalence of tissue fibrosis, manifesting in numerous disease states across myriad organs, therapeutic modalities to prevent or alleviate fibrosis are severely lacking in quantity and efficacy. Alongside development of new drugs, repurposing of existing drugs may be a complementary strategy to elect anti-fibrotic compounds for pharmacologic treatment of tissue fibrosis. Drug repurposing can provide key advantages to de novo drug discovery, harnessing the benefits of previously elucidated mechanisms of action and already existing pharmacokinetic profiles. One class of drugs a wealth of clinical data and extensively studied safety profiles is the statins, a class of antilipidemic drugs widely prescribed for hypercholesterolemia. In addition to these widely utilized lipid-lowering effects, increasing data from cellular, pre-clinical mammalian, and clinical human studies have also demonstrated that statins are able to alleviate tissue fibrosis originating from a variety of pathological insults via lesser-studied, pleiotropic effects of these drugs. Here we review literature demonstrating evidence for direct effects of statins antagonistic to fibrosis, as well as much of the available mechanistic data underlying these effects. A more complete understanding of the anti-fibrotic effects of statins may enable a clearer picture of their anti-fibrotic potential for various clinical indications. Additionally, more lucid comprehension of the mechanisms by which statins exert anti-fibrotic effects may aid in development of novel therapeutic agents that target similar pathways but with greater specificity or efficacy.

Major royal jelly proteins elicited suppression of SARS-CoV-2 entry and replication with halting lung injury

For reasons of high transmissibility and virulence, Alpha (UK, B.1.1.7) and Beta (South African, B.1.351) SARS-CoV-2 variants are classified with other types as variants of concern. Here we report on the influence of royal jelly (RJ) protein fraction (PF)₅₀ (major RJ protein 2 and its isoform X1) on the entry of these variants into the ACE2-human embryonic kidney (HEK) 293 cells using the lentiviral system. The efficiency of PF₅₀ on SARS-CoV-2 replication (RNA-dependent RNA polymerase "RdRp" activity), as well as its impact on bleomycin-induced lung injury in vitro, were also assessed. The PF₅₀ efficiently inhibited infection of kidney cells with the UK and S. African variant spikes of pseudotyped lentivirus particles (IC₅₀ = 7.25 μM and 16.92 μM, respectively) and suppressed the RdRp activity (IC₅₀ = 29.93 μM). Moreover, PF₅₀ displayed protective and therapeutic efficacy against lung injury due to its antioxidant, anti-inflammatory, and angiotensin II blocking activities. The current findings, taken together, offer a novel perspective on PF₅₀ as a promising agent against COVID-19.

Effect of melatonin on oxidative stress indicators in animal models of fibrosis: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Imbalance of oxidative stress has been detected in a range of fibrotic diseases. Melatonin as an indoleamine hormone plays an important role in regulating the circadian rhythm of human, while in recent years, its antioxidant effect has also attracted increasing attention. This study aimed to perform a systematic review and meta-analysis to comprehensively evaluate the antioxidant effect of melatonin in animal models of fibrosis.

METHODS

The PubMed, Cochrane Library, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, China Science and Technology Journal Database (VIP), and SinoMed databases were searched from inception to March 1st, 2022 to retrieve eligible studies that evaluated the effect of melatonin supplementation on the levels of malondialdehyde (MDA), lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and catalase (CAT) in animal models of fibrosis.

RESULTS

A total of 64 studies were included in this meta-analysis. The results showed that melatonin supplementation significantly reduced the levels of oxidative indicators including MDA (P < 0.00001), LPO (P < 0.00001) and NO (P < 0.0001), and elevated the levels of antioxidant indicators including GSH (P < 0.00001), GPx (P < 0.00001) and SOD (P < 0.00001) in fibrotic diseases.

CONCLUSIONS

Our research findings showed that melatonin supplementation could significantly reduce the levels of oxidative indicators including MDA, LPO and NO and elevate the levels of antioxidant indicators including GSH, GPx and SOD so as to correct oxidative stress in animal models of fibrosis. However, no significant changes were observed in CAT level. More clinical studies are needed to further confirm the beneficial role of melatonin in fibrotic diseases.

Diverse functions of apolipoprotein A-I in lung fibrosis

Apolipoprotein A-I (apoA-I) mediates reverse cholesterol transport (RCT) out of cells. In addition to its important role in the RTC, apoA-I also possesses anti-inflammatory and antioxidative functions including the ability to activate inflammasome and signal via toll-like receptors. Dysfunctional apoA-I or its low abundance may cause accumulation of cholesterol mass in alveolar macrophages, leading to the formation of foam cells. Increased numbers of foam cells have been noted in the lungs of mice after experimental exposure to cigarette smoke, silica, or bleomycin and in the lungs of patients suffering from different types of lung fibrosis, including idiopathic pulmonary fibrosis (IPF). This suggests that dysregulation of lipid metabolism may be a common event in the pathogenesis of interstitial lung diseases. Recognition of the emerging role of cholesterol in the regulation of lung inflammation and remodeling provides a challenging concept for understanding lung diseases and offers novel and exciting avenues for therapeutic development. Accordingly, a number of preclinical studies demonstrated decreased expression of inflammatory and profibrotic mediators and preserved lung tissue structure following the administration of the apoA-I or its mimetic peptides. This review highlights the role of apoA-I in lung fibrosis and provides evidence for its potential use in the treatment of this pathological condition.

Lung Pneumonitis and Fibrosis in Cancer Therapy: A Review on Cellular and Molecular Mechanisms

Fibrosis and pneumonitis are the most important side effects of lung tissue following cancer therapy. Radiotherapy and chemotherapy by some drugs, such as bleomycin, can induce pneumonitis and fibrosis. Targeted therapy and immunotherapy also may induce pneumonitis and fibrosis to a lesser extent compared to chemotherapy and radiotherapy. Activation of lymphocytes by immunotherapy or infiltration of inflammatory cells such as macrophages, lymphocytes, neutrophils, and mast cells following chemo/radiation therapy can induce pneumonitis. Furthermore, the polarization of macrophages toward M2 cells and the release of anti-inflammatory cytokines stimulate fibrosis. Lung fibrosis and pneumonitis may also be potentiated by some other changes such as epithelial-mesenchymal transition (EMT), oxidative stress, reduction/oxidation (redox) responses, renin-angiotensin system, and the upregulation of some inflammatory mediators such as a nuclear factor of kappa B (NF-κB), inflammasome, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). Damages to the lung vascular system and the induction of hypoxia also can induce pulmonary injury following chemo/radiation therapy. This review explains various mechanisms of the induction of pneumonitis and lung fibrosis following cancer therapy. Furthermore, the targets and promising agents to mitigate lung fibrosis and pneumonitis will be discussed.

Therapeutic effect of adipose-derived mesenchymal stem cells (AD-MSCs) compared to pirfenidone on corticosteroid resistance in a mouse model of acute exacerbation of idiopathic pulmonary fibrosis

INTRODUCTION

Acute exacerbation-idiopathic pulmonary fibrosis (AE-IPF) is a life-threatening condition. In the treatment of AE-IPF, corticosteroid medication is commonly utilized. However, there is insufficient evidence to justify its usage. Pirfenidone (PFD) has recently been discovered to be effective in the treatment of AE-IPF patients. However, regenerative therapy, such as stem cell therapy or tissue engineering, is necessary due to ineffective and limited therapies. Combining MSC transplantation with pharmacological therapy may also give additional benefits; nevertheless, its use must be proven experimentally. As a result, the goal of this study was to assess the therapeutic effects of adipose-derived mesenchymal stem cells (AD-MSCs) on corticosteroid resistance in an animal model of AE-IPF caused by bleomycin compared to PFD.

MATERIALS AND METHODS

Seventy C57BL/6J male mice were randomly divided into seven groups, control, BLM, methylprednisolone (MP), PFD, AD-MSCs, PFD +MP, and AD-MSCs +MP.

RESULTS

In terms of survival, collagen deposition, the acute lung injury score (ALI), and the Ashcroft score, AD-MSCs exceeded PFD. AD-MSCs + MP provided protection and preserved the lung's architecture in BLM-induced AE. In addition, AD-MSCs successfully decreased chemokine (CC motif) ligand-2 (CCL2) positive cells and lower pro-fibrotic and pro-inflammatory cytokines.

CONCLUSIONS

AD-MSCs enhanced histological structure, Ashcroft and ALI scores, lung collagen deposition, survival, and cytokines in an animal model of AE-IPF. As a result, we believe that AD-MSCs may be more therapeutically helpful for AE-IPF than presently available therapies, either alone or in conjunction with MP.

Plumbagin attenuates Bleomycin-induced lung fibrosis in mice

Background

Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease with limited treatment options. Plumbagin (PL) is an herbal extract with diverse pharmacological effects that have been recently used to treat various types of cancer. This study aims to explore the anti-fibrotic effect of PL and possible underlying mechanisms in IPF.

Methods

We used a bleomycin-induced experimental mouse model of lung fibrosis to assess the potential anti-fibrotic effect of PL. Histological analysis of lung tissue samples by H&E and Masson’s trichrome staining and hydroxyproline assay was performed to evaluate the fibrotic alterations. ELISA and real-time quantitative PCR were conducted to determine the amount of tumor necrosis factor-alpha (TNFα), tumor growth factor-beta (TGF-β), connective tissue growth factor (CTGF), and endothelin-1 (ET-1).

Results

Bleomycin exposure induced lung fibrosis, which was indicated by inflammation, collagen deposition, and structural damage. PL remarkably prevented bleomycin-induced lung fibrosis. Furthermore, PL significantly inhibited TNF-α and TGF-β production. PL also diminished the upregulated expression of CTGF and ET-1 induced by bleomycin.

Conclusion

Overall, our findings suggest PL as an anti-fibrotic agent acting via down-regulation of TGF-β/CTGF or ET-1 axis, as well as TNF-α, to improve lung fibrosis.

Effects of the maternal gut microbiome and gut-placental axis on melatonin efficacy in alleviating cadmium-induced fetal growth restriction

Cadmium (Cd) is a major environmental stressor that induces fetal growth restriction (FGR). Also, changes in gut microbiome diversity-which can be modulated positively by melatonin (Mel) have implications on fetal development and placental functions. Therefore, this study aimed to explore whether the role of Mel in counteracting the Cd-induced FGR by regulating placental barrier injury, endoplasmic reticulum stress (ERS) and mitophagy in pregnant mice is mediated-in part- via the gut microbiota modulations. Pregnant mice were intraperitoneally injected with CdCl₂ (5 mg/kg) and Mel (5 mg/kg) once daily, respectively, at the same time from gestational day (GD) 8 to GD18, and then the maternal colon and placental tissues were collected for detection. To investigate the inner relationship between intestinal flora and the protection of Mel on FGR caused by Cd, gut microbiota transplantation (GMT) was carried out from GD0 to GD18 after the removal of intestinal microbiota by antibiotics. Results indicated that Mel relieved barrier injury, ERS and mitophagy in the placenta, and reversed the maternal gut microbiota dysbiosis. The GMT approach suggested a role of intestinal microbiota in placental barrier injury, ERS and mitophagy induced by Cd. Overall, the results highlighted that the intestinal microbiota and gut-placental axis play a central role in the protective effect of Mel against Cd-induced FGR.

Atorvastatin attenuates pulmonary fibrosis in mice and human lung fibroblasts, by the regulation of myofibroblast differentiation and apoptosis

Statins have anti-inflammatory and antifibrotic effects in addition to cholesterol-lowering effect. We aimed to investigate the effect of atorvastatin (ATR) in fibrotic mouse lung and human lung fibroblasts (MRC5s). Pulmonary fibrosis was induced by a single dose of bleomycin by intratracheal instillation in adult mice. ATR was administered (20 mg/kg ip) to mice with healthy and pulmonary fibrosis for 10 days from Day 7 of the experiment. Mice were dissected on the 21st day. The levels of alpha-smooth muscle actin (α-SMA), pSMAD2/3, LOXL2, and p-Src were determined by Western blot analysis in the lungs. Furthermore, a group of MRC5 was differentiated into myofibroblasts by transforming growth factor-beta (TGF-β). Another group of MRC5s was treated with 10 µM ATR at 24 h after TGF-β stimulation. Cells were collected at 0, 24, 48, and 72 h. The effects of ATR on myofibroblast differentiation, apoptosis, and TGF-β and Wnt/β-catenin signaling activations were examined by Western blot analysis and flow cytometry in MRC5s. ATR attenuated pulmonary fibrosis by regulating myofibroblast differentiation and interstitial accumulation of collagen, by acting on LOXL2, p-Src, and pSMAD2/3 in mice lungs. Additionally, it blocked myofibroblast differentiation via reduced TGF-β and Wnt/β-catenin signaling and decreased α-SMA in MRC5s stimulated with TGF-β. Moreover, ATR caused myofibroblast apoptosis via caspase-3 activation. ATR treatment attenuates pulmonary fibrosis in mice treated with bleomycin. It also inhibits fibroblast/myofibroblast activation, by both reducing myofibroblasts differentiation and inducing myofibroblast apoptosis.

Extracellular Lipids in the Lung and Their Role in Pulmonary Fibrosis

Lipids are major actors and regulators of physiological processes within the lung. Initial research has described their critical role in tissue homeostasis and in orchestrating cellular communication to allow respiration. Over the past decades, a growing body of research has also emphasized how lipids and their metabolism may be altered, contributing to the development and progression of chronic lung diseases such as pulmonary fibrosis. In this review, we first describe the current working model of the mechanisms of lung fibrogenesis before introducing lipids and their cellular metabolism. We then summarize the evidence of altered lipid homeostasis during pulmonary fibrosis, focusing on their extracellular forms. Finally, we highlight how lipid targeting may open avenues to develop therapeutic options for patients with lung fibrosis.

Multifunctional regulatory protein connective tissue growth factor (CTGF): A potential therapeutic target for diverse diseases

Connective tissue growth factor (CTGF), a multifunctional protein of the CCN family, regulates cell proliferation, differentiation, adhesion, and a variety of other biological processes. It is involved in the disease-related pathways such as the Hippo pathway, p53 and nuclear factor kappa-B (NF-κB) pathways and thus contributes to the developments of inflammation, fibrosis, cancer and other diseases as a downstream effector. Therefore, CTGF might be a potential therapeutic target for treating various diseases. In recent years, the research on the potential of CTGF in the treatment of diseases has also been paid more attention. Several drugs targeting CTGF (monoclonal antibodies FG3149 and FG3019) are being assessed by clinical or preclinical trials and have shown promising outcomes. In this review, the cellular events regulated by CTGF, and the relationships between CTGF and pathogenesis of diseases are systematically summarized. In addition, we highlight the current researches, focusing on the preclinical and clinical trials concerned with CTGF as the therapeutic target.

Progress of Statin Therapy in the Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease (ILD) characterized by the proliferation of fibroblasts and aberrant accumulation of extracellular matrix. These changes are accompanied by structural destruction of the lung tissue and the progressive decline of pulmonary function. In the past few decades, researchers have investigated the pathogenesis of IPF and sought a therapeutic approach for its treatment. Some studies have shown that the occurrence of IPF is related to pulmonary inflammatory injury; however, its specific etiology and pathogenesis remain unknown, and no effective treatment, with the exception of lung transplantation, has been identified yet. Several basic science and clinical studies in recent years have shown that statins, the traditional lipid-lowering drugs, exert significant antifibrotic effects, which can delay the progression of IPF and impairment of pulmonary function. This article is aimed at summarizing the current understanding of the pathogenesis of IPF, the progress of research on the use of statins in IPF models and clinical trials, and its main molecular targets.

Natural Product-Based Potential Therapeutic Interventions of Pulmonary Fibrosis

Pulmonary fibrosis (PF) is a disease-refractive lung condition with an increased rate of mortality. The potential factors causing PF include viral infections, radiation exposure, and toxic airborne chemicals. Idiopathic PF (IPF) is related to pneumonia affecting the elderly and is characterized by recurring scar formation in the lungs. An impaired wound healing process, defined by the dysregulated aggregation of extracellular matrix components, triggers fibrotic scar formation in the lungs. The potential pathogenesis includes oxidative stress, altered cell signaling, inflammation, etc. Nintedanib and pirfenidone have been approved with a conditional endorsement for the management of IPF. In addition, natural product-based treatment strategies have shown promising results in treating PF. In this study, we reviewed the recently published literature and discussed the potential uses of natural products, classified into three types—isolated active compounds, crude extracts of plants, and traditional medicine, consisting of mixtures of different plant products—in treating PF. These natural products are promising in the treatment of PF via inhibiting inflammation, oxidative stress, and endothelial mesenchymal transition, as well as affecting TGF-β-mediated cell signaling, etc. Based on the current review, we have revealed the signaling mechanisms of PF pathogenesis and the potential opportunities offered by natural product-based medicine in treating PF.

LDLR dysfunction induces LDL accumulation and promotes pulmonary fibrosis

Treatments for pulmonary fibrosis (PF) are ineffective because its molecular pathogenesis and therapeutic targets are unclear. Here, we show that the expression of low-density lipoprotein receptor (LDLR) was significantly decreased in alveolar type II (ATII) and fibroblast cells, whereas it was increased in endothelial cells from systemic sclerosis-related PF (SSc-PF) patients and idiopathic PF (IPF) patients compared with healthy controls. However, the plasma levels of low-density lipoprotein (LDL) increased in SSc-PF and IPF patients. The disrupted LDL-LDLR metabolism was also observed in four mouse PF models. Upon bleomycin (BLM) treatment, Ldlr-deficient (Ldlr-/-) mice exhibited remarkably higher LDL levels, abundant apoptosis, increased fibroblast-like endothelial and ATII cells and significantly earlier and more severe fibrotic response compared to wild-type mice. In vitro experiments revealed that apoptosis and TGF-β1 production were induced by LDL, while fibroblast-like cell accumulation and ET-1 expression were induced by LDLR knockdown. Treatment of fibroblasts with LDL or culture medium derived from LDL-pretreated endothelial or epithelial cells led to obvious fibrotic responses in vitro. Similar results were observed after LDLR knockdown operation. These results suggest that disturbed LDL-LDLR metabolism contributes in various ways to the malfunction of endothelial and epithelial cells, and fibroblasts during pulmonary fibrogenesis. In addition, pharmacological restoration of LDLR levels by using a combination of atorvastatin and alirocumab inhibited BLM-induced LDL elevation, apoptosis, fibroblast-like cell accumulation and mitigated PF in mice. Therefore, LDL-LDLR may serve as an important mediator in PF, and LDLR enhancing strategies may have beneficial effects on PF.

Evaluation of the efficiency of simvastatin loaded PLGA nanoparticles against acute paraquat-intoxicated rats

Here, we reported a novel nanotherapeutic platform for paraquat (PQ)-induced acute lung injury in animal models using simvastatin (SV) loaded into Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). In this way, Male Wistar rats orally received PQ (120 mg / kg) plus saline, SV (20 mg / kg) or PLGA-SV NPs containing 5, 10 and 20 mg SV/ kg. The levels of TNFα, IL-1β, IL-6 and glutathione content were evaluated. In addition, the pathological changes in the lung were monitored. Our results indicated that PQ (120 mg/kg) significantly reduced the body weight of rats compared to the control group. The most decrease in the level of inflammatory cytokines, bleeding, alveolar destruction as well as lymphocytic infiltration in the lung was observed at group treated with PLGA-SV NPs (10 mg). Free SV (20 mg) as well as PLGA-SV NPs (5 mg) modulated the inflammatory factors and glutathione content, however, they could not prevent tissue damage of PQ. Interestingly, PLGA-SV NPs (20 mg) could not improve the PQ- induced pulmonary damage. In conclusion, PLGA-SV NPs (10 mg) attenuated PQ-induced lung injury. The underlying mechanism may be relevant to increasing glutathione levels and inhibition of the production of inflammatory factors.

The effect of statin therapy on disease-related outcomes in idiopathic pulmonary fibrosis: A systematic review and meta-analysis

BACKGROUND

Idiopathic pulmonary fibrosis is a progressive disease and antifibrotic therapies do not reverse existing fibrosis. There has been emerging evidence of potential role for statins in idiopathic pulmonary fibrosis. The aim of this review is to synthesise the evidence on the efficacy of statins in idiopathic pulmonary fibrosis, focusing on associations with all-cause mortality, disease-specific mortality and change in pulmonary function.

METHODS

Medline and Embase were reviewed to identify relevant publications. Studies were selected if they examined disease-related outcomes including mortality, pulmonary function and adverse events in people with idiopathic pulmonary fibrosis receiving statin therapy.

RESULTS

Five studies with a total of 3407 people with IPF were selected and analysed. The overall risk of bias of five included studies was moderate to serious. In the fixed effect meta-analysis, statin use was associated with a reduction in mortality (RR 0.8; 95% CI 0.72-0.99). However, in the random effects model, there was no longer any significant association between statin use and all-cause mortality (RR 0.87; 95% CI 0.68-1.12). There was no statistically significant association between statin use and decline in FVC % predicted.

CONCLUSION

There is currently insufficient evidence to conclude the effect of statin therapy on disease-related outcomes in idiopathic pulmonary fibrosis. Considering the limitations of available literature, we would recommend a prospective cohort study with capture of dosage and preparation of statin, statin adherence and use of concurrent antifibrotic treatment.

PROSPERO REGISTRATION NUMBER

CRD42019122745.

An updated review of mechanistic potentials of melatonin against cancer: pivotal roles in angiogenesis, apoptosis, autophagy, endoplasmic reticulum stress and oxidative stress

Cancers are serious life-threatening diseases which annually are responsible for millions of deaths across the world. Despite many developments in therapeutic approaches for affected individuals, the rate of morbidity and mortality is high. The survival rate and life quality of cancer patients is still low. In addition, the poor prognosis of patients and side effects of the present treatments underscores that finding novel and effective complementary and alternative therapies is a critical issue. Melatonin is a powerful anticancer agent and its efficiency has been widely documented up to now. Melatonin applies its anticancer abilities through affecting various mechanisms including angiogenesis, apoptosis, autophagy, endoplasmic reticulum stress and oxidative stress. Regarding the implication of mentioned cellular processes in cancer pathogenesis, we aimed to further evaluate the anticancer effects of melatonin via these mechanisms.

miR‑212 promotes renal interstitial fibrosis by inhibiting hypoxia‑inducible factor 1‑α inhibitor

Renal interstitial fibrosis is one of the common causes, and a major pathological basis for the development of various types of chronic progressive renal to end-stage renal diseases. Therefore, it is important to clarify the underlying mechanisms of disease progression in order to develop effective strategies for the treatment and prevention of these pathologies. The aim of the present study was to investigate the association between microRNA (miR)-212 expression and the development of renal interstitial fibrosis, as well as analyzing the role of miR-212 in the disease. The expression of miR-212 was significantly increased in the peripheral blood of patients with renal interstitial fibrosis and in the kidney tissues of unilateral ureteral obstruction (UUO) mice. Angiotensin (Ang) II, TGF-β1 and hypoxia were found to increase the expression of miR-212 and α smooth muscle actin (α-SMA) in NRK49F cells. Ang II stimulation induced the expression of miR-212 and α-SMA in NRK49F cells, while transfection of miR-212 mimics further upregulated the expression of α-SMA. miR-212 was also revealed to target hypoxia-inducible factor 1α inhibitor (HIF1AN) and to upregulate the expression of hypoxia-inducible factor 1α, α-SMA, connective tissue growth factor, collagen α-1(I) chain and collagen α-1(III) chain, whereas HIF1AN overexpression reversed the regulatory effects of miR-212. In UUO mice, miR-212 overexpression promoted the progression of renal interstitial fibrosis, whereas inhibiting miR-212 resulted in the opposite effect. These results indicated that high expression of miR-212 was closely associated with the occurrence of renal interstitial fibrosis, and that miR-212 may promote its development by targeting HIF1AN.

Screening for YAP Inhibitors Identifies Statins as Modulators of Fibrosis

Idiopathic pulmonary fibrosis is a lung disease with limited therapeutic options that is characterized by pathological fibroblast activation and aberrant lung remodeling with scar formation. YAP (Yes-associated protein) is a transcriptional coactivator that mediates mechanical and biochemical signals controlling fibroblast activation. In this study, we developed a high-throughput small-molecule screen for YAP inhibitors in primary human lung fibroblasts. Multiple HMG-CoA (hydroxymethylglutaryl-coenzyme A) reductase inhibitors (statins) were found to inhibit YAP nuclear localization via induction of YAP phosphorylation, cytoplasmic retention, and degradation. We further show that the mevalonate pathway regulates YAP activation, and that simvastatin treatment reduces fibrosis markers in activated human lung fibroblasts and in the bleomycin mouse model of pulmonary fibrosis. Finally, we show that simvastatin modulates YAP in vivo in mouse lung fibroblasts. Our results highlight the potential of small-molecule screens for YAP inhibitors and provide a mechanism for the antifibrotic activity of statins in idiopathic pulmonary fibrosis.

Mitochondrial dysfunction in age-related macular degeneration: melatonin as a potential treatment

Introduction: Age-related Macular Degeneration (AMD), a retinal neurodegenerative disease is the most common cause of blindness among the elderly in developed countries. The impairment of mitochondrial biogenesis has been reported in human retinal pigment epithelium (RPE) cells affected by AMD. Oxidative/nitrosative stress plays an important role in AMD development. The mitochondrial respiratory system is considered a major site of reactive oxygen species (ROS) generation. During aging, insufficient free radical scavenger systems, impairment of DNA repair mechanisms and reduction of mitochondrial degradation and turnover contribute to the massive accumulation of ROS disrupting mitochondrial function. Impaired mitochondrial function leads to the decline in the autophagic capacity and induction of inflammation and apoptosis in human RPE cells affected by AMD.Areas covered: This article evaluates the ameliorative effect of melatonin on AMD and examines AMD pathogenesis with an emphasis on mitochondrial dysfunction. It also considers the potential effects of melatonin on mitochondrial function.Expert opinion: The effect of melatonin on mitochondrial function results in the reduction of oxidative stress, inflammation and apoptosis in the retina; these findings demonstrate that melatonin has the potential to prevent and treat AMD.

Targeting GPCR Signaling for Idiopathic Pulmonary Fibrosis Therapies

A variety of G protein-coupled receptors (GPCRs) have been implicated in the pathogenesis of pulmonary fibrosis, largely through their promotion of profibrotic fibroblast activation. By contrast, recent work has highlighted the beneficial effects of Gαs-coupled GPCRs on reducing fibroblast activation and fibrosis. This review highlights how fibrosis-promoting and -inhibiting GPCR signaling converges on downstream signaling and transcriptional effectors, and how the diversity and dynamics of GPCR expression challenge efforts to identify effective therapies for idiopathic pulmonary fibrosis (IPF). Next-generation strategies to overcome these challenges, focusing on target selection, polypharmacology, and personalized medicine approaches, are discussed as a path towards more effective GPCR-targeted therapies for pulmonary fibrosis.

Simvastatin and ROCK Inhibitor Y-27632 Inhibit Myofibroblast Differentiation of Graves' Ophthalmopathy-Derived Orbital Fibroblasts via RhoA-Mediated ERK and p38 Signaling Pathways

Transforming growth factor-β (TGF-β)-induced differentiation of orbital fibroblasts into myofibroblasts is an important pathogenesis of Graves' ophthalmopathy (GO) and leads to orbital tissue fibrosis. In the present study, we explored the antifibrotic effects of simvastatin and ROCK inhibitor Y-27632 in primary cultured GO orbital fibroblasts and tried to explain the molecular mechanisms behind these effects. Both simvastatin and Y-27632 inhibited TGF-β-induced α-smooth muscle actin (α-SMA) expression, which serves as a marker of fibrosis. The inhibitory effect of simvastatin on TGF-β-induced RhoA, ROCK1, and α-SMA expression could be reversed by geranylgeranyl pyrophosphate, an intermediate in the biosynthesis of cholesterol. This suggested that the mechanism of simvastatin-mediated antifibrotic effects may involve RhoA/ROCK signaling. Furthermore, simvastatin and Y-27632 suppressed TGF-β-induced phosphorylation of ERK and p38. The TGF-β-mediated α-SMA expression was suppressed by pharmacological inhibitors of p38 and ERK. These results suggested that simvastatin inhibits TGF-β-induced myofibroblast differentiation via suppression of the RhoA/ROCK/ERK and p38 MAPK signaling pathways. Thus, our study provides evidence that simvastatin and ROCK inhibitors may be potential therapeutic drugs for the prevention and treatment of orbital fibrosis in GO.

The Role of Airway Myofibroblasts in Asthma

Airway remodeling is a characteristic feature of asthma and is thought to play an important role in the pathogenesis of airway hyperresponsiveness. Myofibroblasts are key structural cells involved in injury and repair, and there is evidence that dysregulation of their normal function contributes to airway remodeling. Despite the importance of myofibroblasts, a lack of specific cellular markers and inconsistent nomenclature have limited recognition of their key role in airway remodeling. Myofibroblasts are increased several-fold in the airways in asthma, in proportion to the severity of the disease. Myofibroblasts are postulated to be derived from both tissue-resident and bone marrow-derived cells, depending on the stage of injury and the tissue. A small number of studies have demonstrated attenuation of myofibroblast numbers and also reversal of established myofibroblast populations in asthma and other inflammatory processes. In this article, we review what is currently known about the biology of myofibroblasts in the airways in asthma and identify potential targets to reduce or reverse the remodeling process. However, further translational research is required to better understand the mechanistic role of the myofibroblast in asthma.

Gastric Acid and Pepsin Work Together in Simulated Gastric Acid Inhalation Leading to Pulmonary Fibrosis in Rats

Background

The clinical association between gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) has been known for many years, but it is still unclear. The present study investigated the association between experimentally simulated aspiration and pulmonary fibrosis.

Material/Methods

A total of 120 male Sprague-Dawley rats were randomly divided into a negative control group, a bleomycin group, and 3 simulated aspiration groups. The bleomycin group was administered a one-time intratracheal injection of bleomycin, whereas the 3 simulated aspiration groups were treated either with an intratracheal instillation of gastric fluid combined with pepsin, with pepsin alone, or with hydrochloric acid, all twice a week, and the negative control group was administered normal saline twice a week. Lung tissues were collected to evaluate pathological changes and the mRNA expression levels of connective tissue growth factor (CTGF), type I collagen, and transforming growth factor.

Results

The results demonstrated that the degree of fibrosis in the early stage was low in each of the 3 simulated aspiration groups, but gradually increased over time. The expression levels of the downstream factor of fibrosis, CTGF, and type I collagen also reflected this trend.

Conclusions

The study demonstrates that aspiration of gastric contents can cause pulmonary fibrosis, and mixed aspiration of pepsin and gastric fluid can accelerate this process. This study provides strong evidence in support of a potential association between human GERD and IPF.

The effects of atorvastatin on the kidney injury in mice with pulmonary fibrosis

OBJECTIVES

The present study investigated the effects of atorvastatin on kidney injury in mice with pulmonary fibrosis (PF).

METHODS

Adult mice were divided into four groups: mice treated with intratracheal bleomycin (I) and their controls (II), and mice treated with atorvastatin for 10 days after 7 days from bleomycin treatment (III) and their controls (IV). Mice were dissected on the 21st day.

KEY FINDINGS

Mononuclear cell infiltrations, injured proximal tubule epithelium and p-c-Jun level increased, while cell proliferation and the levels of p-SMAD2, ELK1, p-ELK1, p-ATF2 and c-Jun decreased in the kidney tissue of mice with PF. The atorvastatin treatments to mice with PF resulted in significant increases at the TGF-β activation, cell proliferation and kidney damage and decreases in the levels of p-SMAD2, p-ELK1, p-ATF2 and p-c-Jun, but not change the p-SMAD3, ELK1 and ATF2 in kidneys.

CONCLUSIONS

The depletion of MAPK signals, rather than SMAD signalling, is effective in kidney damage of mice with PF. Atorvastatin did not regress kidney damage in these mice, whereas it increases the kidney injury. The c-Jun-mediated JNK signals could help kidney repair through cell proliferation. The treatment time and doses of atorvastatin should be optimized for regression of kidney damage.

Atorvastatin attenuates paraquat poisoning-induced epithelial-mesenchymal transition via downregulating hypoxia-inducible factor-1 alpha

AIM

This study investigated the effects of atorvastatin (ATS) on the paraquat (PQ)-induced epithelial-mesenchymal transition (EMT) and the potential mechanism through hypoxia-inducible factor-1 alpha (HIF-1α).

MAIN METHODS

Sprague-Dawley (SD) rats were randomly divided into a control group (n = 5), PQ group (n = 20), PQ + ATS L group (n = 20, ATS 20 mg/kg daily) and PQ + ATS H group (n = 20, ATS 40 mg/kg daily). All treated rats were given a 20% PQ solution (50 mg/kg) once by gavage and then sacrificed 12, 24, 72 and 168 h after PQ exposure. The A549 and RLE-6TN cell lines were treated with ATS, PQ or both for 24 h. Mesenchymal (α-SMA and vimentin) and epithelial (E-cadherin and ZO-1) cell marker expression was tested both in vivo and in vitro. The effects of ATS on HIF-1α and β‑catenin expression were also evaluated.

KEY FINDINGS

ATS alleviated PQ poisoning-induced lung injury and pulmonary fibrosis in vivo. This effect was dose-dependent. ATS treatment attenuated the EMT by increasing the levels of the epithelial markers E-cadherin and ZO-1 and by decreasing the expression of the mesenchymal markers α-SMA and vimentin in both lung tissues and in vitro cell culture. In addition, ATS treatment may decrease the HIF-1α and β‑catenin levels both in vivo and in vitro.

SIGNIFICANCE

In conclusion, ATS can attenuate PQ-induced pulmonary fibrosis. The mechanism may involve the downregulation of the HIF-1α/β‑catenin pathway and the inhibition of the PQ-induced EMT by ATS. ATS may be considered as a therapeutic agent for PQ poisoning-induced pulmonary fibrosis.

Amelioration of bleomycin-induced pulmonary fibrosis by chlorogenic acid through endoplasmic reticulum stress inhibition

To investigate the inhibitory effects of chlorogenic acid on pulmonary fibrosis and the internal mechanisms in vivo and in vitro. 30 male BALB/C mice were randomized into 5 groups: control group, pulmonary fibrosis model group, low, middle and high dose of chlorogenic acid groups. Mice in pulmonary fibrosis model group were administered 5.0 mg/kg bleomycin with intracheal instillation and mice in 3 chlorogenic acid groups were treated with chlorogenic acid every day for 28 days after bleomycin administration. Lung tissue histology was observed using HE staining. Primary pulmonary fibroblasts were isolated and cultured. The expressions of fibrosis related factors (α-SMA and collagen I), as well as ER stress markers (CHOP and GRP78) were determined by both real-time PCR assay and Western blotting, while the expressions of other ER stress signaling pathway factors PERK, IRE-1, ATF-6 and protein levels of caspase-12, caspase-9, caspase-3, PARP were determined by Western blotting. RLE-6TN cell line induced by TGF-β1 was also used to verify the amelioration effects in vitro study. In both in vivo and in vitro studies, TUNEL staining was used to evaluate cell apoptosis. Expressions of collagen I, α-SMA, GRP78, and CHOP were significantly inhibited by chlorogenic acid in dose-dependent manner. Similarly, decreasing levels of cleaved caspase-12, caspase-9, caspase-3 and increasing level of uncleaved PARP were observed in chlorogenic acid groups compared with those in the fibrosis group both in vivo and in vitro. Chlorogenic acid could also significantly down-regulate the level of phosphorylation of PERK and cleaved ATF-6 in vivo study. Moreover, MTT assay demonstrated chlorogenic acid could enhance proliferation of RLE-6TN cells induced by TGFβ1 in vitro. And the apoptosis assays indicated that chlorogenic acid could significantly inhibit cell apoptosis both in vivo and in vitro studies. Chlorogenic acid could inhibit the pulmonary fibrosis through endoplasmic reticulum stress inhibition in vivo and in vitro.

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

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

TGF-β and CTGF are Mitogenic Output Mediators of Wnt/β-Catenin Signaling in Desmoid Fibromatosis

Desmoid fibromatosis is a locally aggressive clonal fibroblastic proliferation with high recurrence rates and no metastatic potential. Implicated molecular aberrations occur within the Wnt/β-catenin pathway (APC and β-catenin gene mutations). Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are profibrotic growth factors, downstream from nuclear translocation of β-catenin, that lead to increased fibrogenesis. CTGF (a downstream effector of TGF-β) is a matricellular protein that modulates the activity of growth factors, adhesion molecules, integrins, and extracellular matrix thus playing a central role in tissue remodeling and fibrosis. Recently there has been growing interest in use of extracellular matrix inhibitors for treatment of various fibrogenic diseases. Desmoid fibromatosis samples (n=15) were evaluated for expression of β-catenin, TGF-β, and CTGF using immunohistochemistry on formalin paraffin-embedded material. A control group comprising scar tissue and adjacent normal skin (n=10) were simultaneously immunostained with above mentioned markers. Real-time polymerase chain reaction was performed on frozen specimens of desmoid fibromatosis (n=6) and normal skin (n=2). All 15 desmoid tumors were positive for β-catenin (surrogate marker of Wnt/β-catenin pathway dysregulation) which was negative in control normal skin and scar samples. TGF-β and CTGF were negative in 9 of 10 normal skin controls. TGF-β and CTGF were positive in all cases of scar tissue. All 15 cases of desmoid tumors were positive for TGF-β and CTGF. The real-time polymerase chain reaction showed higher expression levels of TGF-β and CTGF in desmoid fibromatosis compared with normal skin. The high constitutive expression of β-catenin downstream effectors; TGF-β, CTGF has the potential for enabling targeted therapy.

The role of mast cells and macrophages in amiodarone induced pulmonary fibrosis and the possible attenuating role of atorvastatin

Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ІІ pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition.

Rho inhibition by lovastatin affects apoptosis and DSB repair of primary human lung cells in vitro and lung tissue in vivo following fractionated irradiation

Thoracic radiotherapy causes damage of normal lung tissue, which limits the cumulative radiation dose and, hence, confines the anticancer efficacy of radiotherapy and impacts the quality of life of tumor patients. Ras-homologous (Rho) small GTPases regulate multiple stress responses and cell death. Therefore, we investigated whether pharmacological targeting of Rho signaling by the HMG-CoA-reductase inhibitor lovastatin influences ionizing radiation (IR)-induced toxicity in primary human lung fibroblasts, lung epithelial and lung microvascular endothelial cells in vitro and subchronic mouse lung tissue damage following hypo-fractionated irradiation (4x4 Gy). The statin improved the repair of radiation-induced DNA double-strand breaks (DSBs) in all cell types and, moreover, protected lung endothelial cells from IR-induced caspase-dependent apoptosis, likely involving p53-regulated mechanisms. Under the in vivo situation, treatment with lovastatin or the Rac1-specific small molecule inhibitor EHT1864 attenuated the IR-induced increase in breathing frequency and reduced the percentage of γH2AX and 53BP1-positive cells. This indicates that inhibition of Rac1 signaling lowers IR-induced residual DNA damage by promoting DNA repair. Moreover, lovastatin and EHT1864 protected lung tissue from IR-triggered apoptosis and mitigated the IR-stimulated increase in regenerative proliferation. Our data document beneficial anti-apoptotic and genoprotective effects of pharmacological targeting of Rho signaling following hypo-fractionated irradiation of lung cells in vitro and in vivo. Rac1-targeting drugs might be particular useful for supportive care in radiation oncology and, moreover, applicable to improve the anticancer efficacy of radiotherapy by widening the therapeutic window of thoracic radiation exposure.

Protective Effect of Infliximab, a Tumor Necrosis Factor-Alfa Inhibitor, on Bleomycin-Induced Lung Fibrosis in Rats

We aimed to investigate the preventive effect of Infliximab (IFX), a tumor necrosis factor (TNF)-α inhibitor, on bleomycin (BLC)-induced lung fibrosis in rats. Rats were assigned into four groups as follows: I-BLC group, a single intra-tracheal BLC (2.5 mg/kg) was installed; II-control group, a single intra-tracheal saline was installed; III-IFX + BLC group, a single-dose IFX (7 mg/kg) was administered intraperitoneally (i.p.), 72 h before the intra-tracheal BLC installation; IV-IFX group, IFX (7 mg/kg) was administered alone i.p. on the same day with IFX + BLC group. All animals were sacrificed on the 14th day of BLC installation. Levels of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interleukin (IL)-6, periostin, YKL-40, nitric oxide (NO) in rat serum were measured, as well as, myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity, and reduced glutathione (GSH), hydroxyproline, malondialdehyde (MDA) content in lung homogenates. Lung tissues were stained with hematoxylin and eosin (H&E) for quantitative histological evaluation. The inducible nitric oxide synthase (iNOS) expression and cell apoptosis in the lung tissues were determined quantitatively by immunohistochemical staining (INOS) and by TUNNEL staining, respectively. BLC installation worsened antioxidant status (such as SOD, CAT, GPx, GSH, MPO), while it increased the serum TNF-α, TGF-β, IL-6, periostin, YKL-40, and lipid peroxidation, and collagen deposition, measured by MDA and hydroxyproline, respectively. IFX pretreatment improved antioxidant status as well as BLC-induced lung pathological changes, while it decreased the TNF-α, TGF-β, IL-6, periostin, YKL-40, lipid peroxidation and collagen deposition. Finally, histological, immunohistochemical, and TUNNEL evidence also supported the ability of IFX to prevent BLC-induced lung fibrosis. The results of the present study indicate that IFX pretreatment can attenuate BLC-induced pulmonary fibrosis.

Simvastatin inhibits glucose uptake activity and GLUT4 translocation through suppression of the IR/IRS-1/Akt signaling in C2C12 myotubes

Simvastatin,a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, is clinically used in the prevention and treatment of cardiovascular diseases. Numerous studies demonstrate that statins increase the risk of new-onset diabetes in long-term therapy, but mechanisms underpinning this effect are still unclear. Here, we investigated whether simvastatin inhibited the glucose uptake activity and the underlying mechanisms in C2C12 myotubes. Our studies showed that simvastatin significantly inhibited glucose uptake activity and GLUT4 translocation, whereas the effect was reversible with mevalonolactone (ML), which acts as an intermediate of cholesterol synthesis pathway. Mechanistically, the inhibition of glucose uptake and GLUT4 translocation elicited by simvastatin were associated with the suppression of the insulin receptor (IR)/IR substrate (IRS)/Akt signaling cascade. Simvastatin suppressed the phosphorylation of IR, IRS-1 and Akt, and total expression of IR or IRS-1, but did not affect Akt. Furthermore, simvastatin decreased Rac1 GTP binding. In conclusion, our findings indicate that simvastatin suppresses glucose uptake activity and GLUT4 translocation via IR-dependent IRS-1/PI3K/Akt pathway. These results provide an important new insight into the mechanism of statins on insulin sensitivity which may be associated with new-onset diabetes.

Preventive Effects of Rhodiola rosea L. on Bleomycin-Induced Pulmonary Fibrosis in Rats

Rhodiola rosea L. (RRL) possesses a wide range of pharmacological properties, including lung-protective activity, and has been utilized in folk medicine for several 100 years. However, the lung-protective mechanism remains unclear. This study investigated the possible lung-protective activity mechanism of RRL in a pulmonary fibrosis (PF) rat model. Lung fibrotic injury was induced in Sprague-Dawley rats by single intratracheal instillation of saline containing bleomycin (BLM; 5 mg/kg). The rats were administered 125, 250, or 500 mg/kg of a 95% ethanol extract of RRL for 28 days. The animals were killed to detect changes in body weight, serum levels of glutathione (GSH) and total superoxide dismutase (T-SOD), as well as lung tissue hydroxyproline (HYP) content. Tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin 6 (IL-6) levels were measured in bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining were performed to observe the histopathological changes in lung tissues. Additionally, target-related proteins were measured by Western blotting. RRL alleviated the loss of body weight induced by instilling BLM in PF rats, particularly at the 500 mg/kg per day dose. RRL reduced HYP (p < 0.01) and increased GSH and T-SOD contents. BALF levels of TNF-α, TGF-β1, and IL-6 decreased significantly in the RRL-treated groups. Expression levels of matrix metalloproteinase-9 (MMP-9) and α-smooth muscle actin decreased significantly in a dose-dependent manner in response to RRL. Moreover, the levels of TGF-β1 and tissue inhibitor of metalloproteinase-1 in lung tissues also decreased in the RRL-treated groups. RRL alleviated BLM-induced PF in rats. Our results reveal that the protective effects of RRL against fibrotic lung injury in rats are correlated with its anti-inflammatory, antioxidative, and anti-fibrotic properties. MMP-9 may play important roles in BLM-induced PF.

Grape seed and skin extract protects against bleomycin-induced oxidative stress in rat lung

INTRODUCTION

Lung fibrosis is a common side effect of the chemotherapeutic agent bleomycin and current evidence suggests that reactive oxygen species play a key role in the development of lung injury. We examined whether grape seed and skin extract (GSSE), a polyphenolic mixture exhibiting antioxidant properties, is able to protect against bleomycin-induced lung oxidative stress and injury.

METHODS

Rats were pre-treated during three weeks either with vehicle (ethanol 10% control) or GSSE (4g/kg), then administered with a single high dose bleomycin (15mg/kg) at the 7th day.

RESULTS

Bleomycin increased lung lipoperoxidation, carbonylation and decreased antioxidant enzyme activities as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx). Bleomycin also induced copper depletion from the lung and iron accumulation within the lung, but had no effect on either zinc nor manganese. Correlatively bleomycin decreased the copper associated enzyme tyrosinase, increased the zinc dependent lactate dehydrogenase (LDH) and did not affect the manganese dependent glutamine synthetase. GSSE efficiently counteracted almost all bleomycin-induced oxidative stress, biochemical and morphological changes of lung tissue.

CONCLUSION

Data suggest that GSSE exerts potent antioxidant properties that could find potential application in the protection against bleomycin-induced lung fibrosis.

Skin Antiageing and Systemic Redox Effects of Supplementation with Marine Collagen Peptides and Plant-Derived Antioxidants: A Single-Blind Case-Control Clinical Study

Recently, development and research of nutraceuticals based on marine collagen peptides (MCPs) have been growing due to their high homology with human collagens, safety, bioavailability through gut, and numerous bioactivities. The major concern regarding safety of MCPs intake relates to increased risk of oxidative stress connected with collagen synthesis (likewise in fibrosis) and to ROS production by MCPs-stimulated phagocytes. In this clinical-laboratory study, fish skin MCPs combined with plant-derived skin-targeting antioxidants (AO) (coenzyme Q10 + grape-skin extract + luteolin + selenium) were administered to volunteers (n = 41). Skin properties (moisture, elasticity, sebum production, and biological age) and ultrasonic markers (epidermal/dermal thickness and acoustic density) were measured thrice (2 months before treatment and before and after cessation of 2-month oral intake). The supplementation remarkably improved skin elasticity, sebum production, and dermal ultrasonic markers. Metabolic data showed significant increase of plasma hydroxyproline and ATP storage in erythrocytes. Redox parameters, GSH/coenzyme Q10 content, and GPx/GST activities were unchanged, while NO and MDA were moderately increased within, however, normal range of values. Conclusions. A combination of MCPs with skin-targeting AOs could be effective and safe supplement to improve skin properties without risk of oxidative damage.

Therapeutic Effect of Adipose Derived Stem Cells versus Atorvastatin on Amiodarone Induced Lung Injury in Male Rat

Background and Objectives

Amiodarone (AM), a class 3 antiarrhythmic drug, has been associated with variety of adverse effects, the most serious of which is pulmonary toxicity. Ator (A) is a statin, known for their immunomodulatory and anti-inflammatory activities. Recent studies provide evidence of potential therapeutic effect of statins on lung injury. Adipose derived stem cells (ADSCs) have shown great promise in the repair of various tissues. The present study aimed at investigating and comparing the possible therapeutic effect of A and ADSCs on AM induced lung injury in albino rats.

Methods and Results

34 adult male albino rats were divided into 5 groups: control group (Gp I), A group (Gp II) received 10 mg/kg of A orally 6 days (d)/week (w) for 4 weeks (ws), AM group (Gp III) received 30 mg/kg of AM orally 6 d/w for 4 ws, AM&A group (Gp IV) received AM for 4ws then A for other 4 ws and AM&SCs group (Gp V) received AM for 4 ws then injected with 0.5 ml ADSCs on 2 successive days intravenously (IV). Histological, histochemical, immunohistochemical and morphometric studies were performed. Group III displayed bronchiolitis obliterans, thickened interalveolar septa (IAS) and thickened vascular wall which were proven morphometrically. Increased area% of collagen fibers and apoptotic changes were recorded. All findings regressed on A administration and ADSCs therapy.

Conclusion

Ator proved a definite ameliorating effect on the degenerative, inflammatory, apoptotic and fibrotic changes induced by AM. ADSCs administration denoted more remarkable therapeutic effect compared to A.

CCN1 acutely increases nitric oxide production via integrin αvβ3-Akt-S6K-phosphorylation of endothelial nitric oxide synthase at the serine 1177 signaling axis

Although CCN1 (also known as cysteine-rich, angiogenic inducer 61, CYR61) has been reported to promote angiogenesis and neovascularization in endothelial cells (ECs), its effects on endothelial nitric oxide (NO) production have never been studied. Using human umbilical vein ECs, we investigated whether and how CCN1 regulates NO production. CCN1 acutely increased NO production in a time- and dose-dependent manner, which was accompanied by increased phosphorylation of endothelial NO synthase (eNOS) at serine 1177 (eNOS-Ser(1177)), but not that of eNOS-Thr(495) or eNOS-Ser(114). The level of total eNOS expression was unaltered. Treatment with either LY294002, a selective inhibitor of phosphoinositide 3-kinase known as an upstream kinase of Akt, or H-89, an inhibitor of protein kinase A, mitogen- and stress-activated protein kinase 1, Rho-associated protein kinase 2, and ribosomal protein S6 kinase (S6K), inhibited CCN1-stimulated eNOS-Ser(1177) phosphorylation and subsequent NO production. Ectopic expression of small interfering RNA against Akt and S6K significantly inhibited the effects of CCN1. Consistently, CCN1 increased the phosphorylation of Akt-Ser(473) and S6K-Thr(389). However, CCN1 did not alter the expression or secretion of VEGF, a known downstream factor of CCN1 and a potential upstream factor of Akt-mediated eNOS-Ser(1177) phosphorylation. Furthermore, neutralization of integrin αvβ3 with corresponding antibody completely reversed all of the observed effects of CCN1. Moreover, CCN1 increased acetylcholine-induced relaxation in the rat aortas. Finally, we also found that CCN1-stimulated eNOS-Ser(1177) phosphorylation and NO production are true for other types of EC tested. In conclusion, CCN1 acutely increases NO production via activation of a signaling axis in integrin αvβ3-Akt-S6K-eNOS-Ser(1177) phosphorylation, suggesting an important role for CCN1 in vasodilation.

Role of GADD45a in murine models of radiation- and bleomycin-induced lung injury

We previously reported protective effects of GADD45a (growth arrest and DNA damage-inducible gene 45 alpha) in murine ventilator-induced lung injury (VILI) via effects on Akt-mediated endothelial cell signaling. In the present study we investigated the role of GADD45a in separate murine models of radiation- and bleomycin-induced lung injury. Initial studies of wild-type mice subjected to single-dose thoracic radiation (10 Gy) confirmed a significant increase in lung GADD45a expression within 24 h and persistent at 6 wk. Mice deficient in GADD45a (GADD45a(-/-)) demonstrated increased susceptibility to radiation-induced lung injury (RILI, 10 Gy) evidenced by increased bronchoalveolar lavage (BAL) fluid total cell counts, protein and albumin levels, and levels of inflammatory cytokines compared with RILI-challenged wild-type animals at 2 and 4 wk. Furthermore, GADD45a(-/-) mice had decreased total and phosphorylated lung Akt levels both at baseline and 6 wk after RILI challenge relative to wild-type mice while increased RILI susceptibility was observed in both Akt(+/-) mice and mice treated with an Akt inhibitor beginning 1 wk prior to irradiation. Additionally, overexpression of a constitutively active Akt1 transgene reversed RILI-susceptibility in GADD45a(-/-) mice. In separate studies, lung fibrotic changes 2 wk after treatment with bleomycin (0.25 U/kg IT) was significantly increased in GADD45a(-/-) mice compared with wild-type mice assessed by lung collagen content and histology. These data implicate GADD45a as an important modulator of lung inflammatory responses across different injury models and highlight GADD45a-mediated signaling as a novel target in inflammatory lung injury clinically.

Simvastatin impairs the induction of pulmonary fibrosis caused by a western style diet: a preliminary study

The role of an atherogenic diet in causing pulmonary fibrosis has received little attention and simvastatin has been shown to reduce pulmonary fibrosis in animal models. To determine if an atherogenic diet can induce pulmonary fibrosis and whether simvastatin treatment is beneficial by up-regulating heat shock protein 70 and 90. New Zealand white rabbits (n = 15) were divided: Group 1 (control); Group 2 (MC) received a normal rabbit diet with 1% methionine plus 0.5% cholesterol (atherogenic diet). Group 3 received the same diet as the MC group plus 5 mg/kg/day simvastatin orally (MCS). After 4 weeks, the lungs were collected and analysed. Picrosirus red staining of lung interstitial collagen content showed that the atherogenic diet increased fibrosis 2.9-fold (P < 0.05), bronchiole adventitial collagen was increased 2.3-fold (P < 0.05) and bronchiole epithelium was increased 34-fold (P < 0.05), and simvastatin treatment severely reduced this effect (P < 0.05). Western blot analysis showed that the atherogenic diet significantly reduced lung Hsp70 protein by 22% (P < 0.05) and Hsp90 protein by 18% (P < 0.05) and simvastatin treatment did not affect this result. However, aortic hyper-responsiveness to vasoconstrictors (angiotensin II and phenylephrine) were markedly reduced by simvastatin treatment. We report that an atherogenic diet stimulates pulmonary fibrosis and reduces lung Hsp70/Hsp90 protein concentration. Simvastatin impairs this by mechanisms unrelated to Hsp70/Hsp90, but possibly a reduction in angiotensin II receptor or alpha adrenergic receptor pathways. These results could have implications in idiopathic pulmonary fibrosis.

Atorvastatin Treatment for Atrial Fibrillation Reduces Serum High-Sensitivity C-Reactive Protein Levels

We investigated whether serum hs-CRP levels predict the efficacy of atrial fibrillation (AF) treated with atorvastatin. Bibliographic databases were exhaustively searched for studies relevant to the research topic. Newcastle-Ottawa Scale (NOS) criteria, combined with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS), were applied for study quality assessment. Our meta-analysis identified seven cohort studies (2006~2013), providing information on the change in serum hs-CRP levels in AF patients receiving atorvastatin therapy. After atorvastatin treatment, hs-CRP level in AF patients decreased significantly (SMD = 1.02, 95% CI: 0.58–1.47, P < 0.001). Subgroup analysis by country and hs-CRP detection methods suggested a negative relationship between atorvastatin treatment and hs-CRP levels among Chinese AF patients (SMD = 1.34, 95% CI: 1.00–1.69, P < 0.001) and by using ELISA method (SMD = 1.11, 95% CI: 0.51–1.71, P < 0.001), but not among Turkish population and using INA method (all P > 0.05). Egger's test showed no publication bias (P = 0.450). hs-CRP was clearly lowered in AF patients treated with atorvastatin, which may be helpful in the choice of statin agents for AF treatment. However, longer follow-ups are necessary to assess the clinical value of lowering hs-CRP in the clinical setting of AF treatment outcomes.