Curcumin-loaded liposomes modulating the synergistic role of EpCAM and estrogen receptor alpha in lung cancer management

Lung cancer (LC) remains a leading cause of cancer-related mortality worldwide, necessitating the exploration of innovative therapeutic strategies. This study delves into the in vitro potential of liposomal therapeutics utilizing Curcumin-loaded PlexoZome® (CUR-PLXZ) in targeting EpCAM/TROP1 and Estrogen Receptor Alpha (ERα) signalling pathways for LC management. The prevalence of LC, particularly non-small cell lung cancer (NSCLC), underscores the urgent need for effective treatments. Biomarkers like EpCAM/TROP1 and ERα/NR3A1 play crucial roles in guiding targeted therapies and influencing prognosis. EpCAM plays a key role in cell-cell adhesion and signalling along with ERα which is a nuclear receptor that binds estrogen and regulates gene expression in response to hormonal signals. In LC, both often get overexpressed and are associated with tumour progression, metastasis, and poor prognosis. Curcumin, a phytochemical with diverse therapeutic properties, holds promise in targeting these pathways. However, its limited solubility and bioavailability necessitate advanced formulations like CUR-PLXZ. Our study investigates the biological significance of these biomarkers in the A549 cell line and explores the therapeutic potential of CUR-PLXZ, which modulates the expression of these two markers. An in vitro analysis of the A549 human lung adenocarcinoma cell line identified that CUR-PLXZ at a dose of 5 μM effectively inhibited the expression of EpCAM and ERα. This finding paves the way for targeted intervention strategies in LC management.

18-β-glycyrrhetinic acid-loaded polymeric nanoparticles attenuate cigarette smoke-induced markers of impaired antiviral response in vitro

Tobacco smoking is a leading cause of preventable mortality, and it is the major contributor to diseases such as COPD and lung cancer. Cigarette smoke compromises the pulmonary antiviral immune response, increasing susceptibility to viral infections. There is currently no therapy that specifically addresses the problem of impaired antiviral response in cigarette smokers and COPD patients, highlighting the necessity to develop novel treatment strategies. 18-β-glycyrrhetinic acid (18-β-gly) is a phytoceutical derived from licorice with promising anti-inflammatory, antioxidant, and antiviral activities whose clinical application is hampered by poor solubility. This study explores the therapeutic potential of an advanced drug delivery system encapsulating 18-β-gly in poly lactic-co-glycolic acid (PLGA) nanoparticles in addressing the impaired antiviral immunity observed in smokers and COPD patients. Exposure of BCi-NS1.1 human bronchial epithelial cells to cigarette smoke extract (CSE) resulted in reduced expression of critical antiviral chemokines (IP-10, I-TAC, MIP-1α/1β), mimicking what happens in smokers and COPD patients. Treatment with 18-β-gly-PLGA nanoparticles partially restored the expression of these chemokines, demonstrating promising therapeutic impact. The nanoparticles increased IP-10, I-TAC, and MIP-1α/1β levels, exhibiting potential in attenuating the negative effects of cigarette smoke on the antiviral response. This study provides a novel approach to address the impaired antiviral immune response in vulnerable populations, offering a foundation for further investigations and potential therapeutic interventions. Further studies, including a comprehensive in vitro characterization and in vivo testing, are warranted to validate the therapeutic efficacy of 18-β-gly-PLGA nanoparticles in respiratory disorders associated with compromised antiviral immunity.

Ribavirin attenuates carcinogenesis by downregulating IL-6 and IL-8 in vitro in human lung adenocarcinoma

Lung cancer is one of the leading causes of death worldwide, whereby the major contributing factors are cigarette smoking and exposure to environmental pollutants. Despite the availability of numerous treatment options, including chemotherapy, the five-year survival rate is still extremely low, highlighting the urgent need to develop novel, more effective therapeutic strategies. In this context, the repurposing of previously approved drugs is an advantage in terms of time and resources invested. Ribavirin is an antiviral drug approved for the treatment of hepatitis C, which shows potential for repurposing as an anticancer agent. Among the many signaling molecules promoting carcinogenesis, the interleukins (ILs) IL-6 and IL-8 are interesting therapeutic targets as they promote a variety of cancer hallmarks such as cell proliferation, migration, metastasis, and angiogenesis. In the present study, we show that ribavirin significantly downregulates the expression of IL-6 and IL-8 in vitro in A549 human lung adenocarcinoma cells. The results of this study shed light on the anticancer mechanisms of ribavirin, providing further proof of its potential as a repurposed drug for the treatment of lung cancer.

Applications and advancements of nanoparticle-based drug delivery in alleviating lung cancer and chronic obstructive pulmonary disease

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are among the leading causes of mortality worldwide. Cigarette smoking is among the main aetiologic factors for both ailments. These diseases share common pathogenetic mechanisms including inflammation, oxidative stress, and tissue remodelling. Current therapeutic approaches are limited by low efficacy and adverse effects. Consequentially, LC has a 5-year survival of < 20%, while COPD is incurable, underlining the necessity for innovative treatment strategies. Two promising emerging classes of therapy against these diseases include plant-derived molecules (phytoceuticals) and nucleic acid-based therapies. The clinical application of both is limited by issues including poor solubility, poor permeability, and, in the case of nucleic acids, susceptibility to enzymatic degradation, large size, and electrostatic charge density. Nanoparticle-based advanced drug delivery systems are currently being explored as flexible systems allowing to overcome these limitations. In this review, an updated summary of the most recent studies using nanoparticle-based advanced drug delivery systems to improve the delivery of nucleic acids and phytoceuticals for the treatment of LC and COPD is provided. This review highlights the enormous relevance of these delivery systems as tools that are set to facilitate the clinical application of novel categories of therapeutics with poor pharmacokinetic properties. This picture was generated with BioRender.

Emerging applications and prospects of NFκB decoy oligodeoxynucleotides in managing respiratory diseases

Chronic respiratory diseases like asthma and Chronic Obstructive Pulmonary Disease (COPD) have been a burden to society for an extended period. Currently, there are only preventative treatments in the form of mono- or multiple-drug therapy available to patients who need to utilize it daily. Hence, throughout the years there has been a substantial amount of research in understanding what causes inflammation in the context of these diseases. For example, the transcription factor NFκB has a pivotal role in causing chronic inflammation. Subsequent research has been exploring ways to block the activation of NFκB as a potential therapeutic strategy for many inflammatory diseases. One of the possible ways through which this is probable is the utilisation of decoy oligodeoxynucleotides, which are synthetic, short, single-stranded DNA fragments that mimic the consensus binding site of a targeted transcription factor, thereby functionally inactivating it. However, limitations to the implementation of decoy oligodeoxynucleotides include their rapid degradation by intracellular nucleases and the lack of targeted tissue specificity. An advantageous approach to overcome these limitations involves using nanoparticles as a vessel for drug delivery. In this review, all of those key elements will be explored as to how they come together as an application to treat chronic inflammation in respiratory diseases.

Agarwood oil nanoemulsion counteracts LPS-induced inflammation and oxidative stress in RAW264.7 mouse macrophages

PURPOSE

Oxidative stress and inflammation are key pathophysiological features of chronic respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD). Agarwood oil obtained from Aquilaria trees has promising antioxidant and anti-inflammatory activities. However, its clinical application is hampered by poor solubility. A viable approach to overcome this involves formulation of oily constituents into emulsions. Here, we have investigated the antioxidant and anti-inflammatory potential of an agarwood oil-based nanoemulsion (DE'RAAQSIN) against lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages in vitro.

METHODS

The antioxidant and anti-inflammatory activity of DE'RAAQSIN was assessed by measuring the levels of ROS and nitric oxide (NO) produced, using the DCF-DA assay and the Griess reagent assay, respectively. The molecular pathways activated by DE'RAAQSIN were investigated via qPCR.

RESULTS

LPS stimulation of RAW264.7 cells increased the production of nitric oxide (NO) and ROS and resulted in the overexpression of the inducible nitric oxide synthase (iNOS) gene. Furthermore, LPS induced the upregulation of the expression of key proinflammatory genes (IL-6, TNF-α, IL-1β, and CXCL1) and of the antioxidant gene heme oxygenase-1 (HO-1). DE'RAAQSIN demonstrated potent antioxidant and anti-inflammatory activity by significantly reducing the levels of ROS and of secreted NO, simultaneously counteracting the LPS-induced overexpression of iNOS, IL-6, TNF-α, IL-1β, and HO-1. These findings were corroborated by in silico activity prediction and physicochemical analysis of the main agarwood oil components.

CONCLUSIONS

We propose DE'RAAQSIN as a promising alternative managing inflammatory disorders, opening the platform for further studies aimed at understanding the effectiveness of DE'RAAQSIN.

Berberine-loaded engineered nanoparticles attenuate TGF-β-induced remodelling in human bronchial epithelial cells

Airway remodelling occurs in chronic respiratory diseases (CRDs) such as asthma and chronic obstructive pulmonary disease (COPD). It is characterized by aberrant activation of epithelial reparation, excessive extracellular matrix (ECM) deposition, epithelial-to-mesenchymal transition (EMT), and airway obstruction. The master regulator is Transforming Growth Factor-β (TGF-β), which activates tissue repair, release of growth factors, EMT, increased cell proliferation, and reduced nitric oxide (NO) secretion. Due to its fundamental role in remodelling, TGF-β is an emerging target in the treatment of CRDs. Berberine is a benzylisoquinoline alkaloid with antioxidant, anti-inflammatory, and anti-fibrotic activities whose clinical application is hampered by poor permeability. To overcome these limitations, in this study, berberine was encapsulated in monoolein-based liquid crystalline nanoparticles (BM-LCNs). The potential of BM-LCNs in inhibiting TGF-β-induced remodelling features in human bronchial epithelial cells (BEAS-2B) was tested. BM-LCNs significantly inhibited TGF-β-induced migration, reducing the levels of proteins upregulated by TGF-β including endoglin, thrombospondin-1, basic fibroblast growth factor, vascular-endothelial growth factor, and myeloperoxidase, and increasing the levels of cystatin C, a protein whose expression was downregulated by TGF-β. Furthermore, BM-LCNs restored baseline NO levels downregulated by TGF-β. The results prove the in vitro therapeutic efficacy of BM-LCNs in counteracting TGF-β-induced remodelling features. This study supports the suitability of berberine-loaded drug delivery systems to counteract airway remodelling, with potential application as a treatment strategy against CRDs.

Sexual dimorphism in chronic respiratory diseases

Sex differences in susceptibility, severity, and progression are prevalent for various diseases in multiple organ systems. This phenomenon is particularly apparent in respiratory diseases. Asthma demonstrates an age-dependent pattern of sexual dimorphism. However, marked differences between males and females exist in other pervasive conditions such as chronic obstructive pulmonary disease (COPD) and lung cancer. The sex hormones estrogen and testosterone are commonly considered the primary factors causing sexual dimorphism in disease. However, how they contribute to differences in disease onset between males and females remains undefined. The sex chromosomes are an under-investigated fundamental form of sexual dimorphism. Recent studies highlight key X and Y-chromosome-linked genes that regulate vital cell processes and can contribute to disease-relevant mechanisms. This review summarises patterns of sex differences in asthma, COPD and lung cancer, highlighting physiological mechanisms causing the observed dimorphism. We also describe the role of the sex hormones and present candidate genes on the sex chromosomes as potential factors contributing to sexual dimorphism in disease.

Targeting mucus barrier in respiratory diseases by chemically modified advanced delivery systems

Mucus gel constitutes of heavily cross-linked mucin fibers forming a viscoelastic, dense porous network that coats all the exposed epithelia not covered with the skin. The layer provides protection to the underlying gastrointestinal, respiratory, and female reproductive tracts, in addition to the organs such as the surface of eye by trapping the pathogens, irritants, environmental fine particles, and potentially hazardous foreign matter. However, this property of mucus gel poses a substantial challenge for realizing the localized and sustained drug delivery across the mucosal surfaces. The mucus permeating particles that spare the protective properties of mucus gel improve the therapeutic potency of the drugs aimed at the management of diseases, including sexually transmitted infections, lung cancer, irritable bowel disease, degenerative eye diseases and infections, and cystic fibrosis. As such, the mucoadhesive materials conjugated with drug molecules display a prolonged retention time in the mucosal gel that imparts a sustained release of the deliberated drug molecules across the mucosa. The contemporarily developed mucus penetrating materials for drug delivery applications comprise of a finer size, appreciable hydrophilicity, and a neutral surface to escape the entrapment within the cross-inked mucus fibers. Pertaining to the mucus secretion as a first line of defence in respiratory tract in response to the invading physical, chemical, and biological pathogens, the development of mucus penetrating materials hold promise as a stalwart approach for revolutionizing the respiratory drug delivery paradigm. The present review provides an epigrammatic collation of the mucus penetrating/mucoadhesive materials for achieving a controlled/sustained release of the cargo pharmaceutics and drug molecules across the respiratory mucus barrier.

Autoantibodies and autoimmune disorders in SARS-CoV-2 infection: pathogenicity and immune regulation

Coronavirus disease 2019 (COVID-19) is an infectious disease associated with the respiratory system caused by the SARS-CoV-2 virus. The aim of this review article is to establish an understanding about the relationship between autoimmune conditions and COVID-19 infections. Although majority of the population have been protected with vaccines against this virus, there is yet a successful curative medication for this disease. The use of autoimmune medications has been widely considered to control the infection, thus postulating possible relationships between COVID-19 and autoimmune diseases. Several studies have suggested the correlation between autoantibodies detected in patients and the severity of the COVID-19 disease. Studies have indicated that the SARS-CoV-2 virus can disrupt the self-tolerance mechanism of the immune system, thus triggering autoimmune conditions. This review discusses the current scenario and future prospects of promising therapeutic strategies that may be employed to regulate such autoimmune conditions.

Advances and applications of monoolein as a novel nanomaterial in mitigating chronic lung diseases

Chronic lung diseases such as asthma, chronic obstructive pulmonary disease, lung cancer, and the recently emerged COVID-19, are a huge threat to human health, and among the leading causes of global morbidity and mortality every year. Despite availability of various conventional therapeutics, many patients remain poorly controlled and have a poor quality of life. Furthermore, the treatment and diagnosis of these diseases are becoming increasingly challenging. In the recent years, the application of nanomedicine has become increasingly popular as a novel strategy for diagnosis, treatment, prevention, as well as follow-up of chronic lung diseases. This is attributed to the ability of nanoscale drug carriers to achieve targeted delivery of therapeutic moieties with specificity to diseased site within the lung, thereby enhancing therapeutic outcomes of conventional therapies whilst minimizing the risks of adverse reactions. For this instance, monoolein is a polar lipid nanomaterial best known for its versatility, thermodynamic stability, biocompatibility, and biodegradability. As such, it is commonly employed in liquid crystalline systems for various drug delivery applications. In this review, we present the applications of monoolein as a novel nanomaterial-based strategy for targeted drug delivery with the potential to revolutionize therapeutic approaches in chronic lung diseases.

Nutraceuticals and mitochondrial oxidative stress: bridging the gap in the management of bronchial asthma

Asthma is a chronic inflammatory disease primarily characterized by inflammation and reversible bronchoconstriction. It is currently one of the leading causes of morbidity and mortality in the world. Oxidative stress further complicates the pathology of the disease. The current treatment strategies for asthma mainly involve the use of anti-inflammatory agents and bronchodilators. However, long-term usage of such medications is associated with severe adverse effects and complications. Hence, there is an urgent need to develop newer, novel, and safe treatment modalities for the management of asthma. This has therefore prompted further investigations and detailed research to identify and develop novel therapeutic interventions from potent untapped resources. This review focuses on the significance of oxidative stressors that are primarily derived from both mitochondrial and non-mitochondrial sources in initiating the clinical features of asthma. The review also discusses the biological scavenging system of the body and factors that may lead to its malfunction which could result in altered states. Furthermore, the review provides a detailed insight into the therapeutic role of nutraceuticals as an effective strategy to attenuate the deleterious effects of oxidative stress and may be used in the mitigation of the cardinal features of bronchial asthma.

Nutraceuticals: unlocking newer paradigms in the mitigation of inflammatory lung diseases

Persistent respiratory tract inflammation contributes to the pathogenesis of various chronic respiratory diseases, such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. These inflammatory respiratory diseases have been a major public health concern as they are the leading causes of worldwide mortality and morbidity, resulting in heavy burden on socioeconomic growth throughout these years. Although various therapeutic agents are currently available, the clinical applications of these agents are found to be futile due to their adverse effects, and most patients remained poorly controlled with a low quality of life. These drawbacks have necessitated the development of novel, alternative therapeutic agents that can effectively improve therapeutic outcomes. Recently, nutraceuticals such as probiotics, vitamins, and phytochemicals have gained increasing attention due to their nutritional properties and therapeutic potential in modulating the pathological mechanisms underlying inflammatory respiratory diseases, which could ultimately result in improved disease control and overall health outcomes. As such, nutraceuticals have been held in high regard as the possible alternatives to address the limitations of conventional therapeutics, where intensive research are being performed to identify novel nutraceuticals that can positively impact various inflammatory respiratory diseases. This review provides an insight into the utilization of nutraceuticals with respect to their molecular mechanisms targeting multiple signaling pathways involved in the pathogenesis of inflammatory respiratory diseases.

Treatment of chronic airway diseases using nutraceuticals: Mechanistic insight

Respiratory diseases, both acute and chronic, are reported to be the leading cause of morbidity and mortality, affecting millions of people globally, leading to high socio-economic burden for the society in the recent decades. Chronic inflammation and decline in lung function are the common symptoms of respiratory diseases. The current treatment strategies revolve around using appropriate anti-inflammatory agents and bronchodilators. A range of anti-inflammatory agents and bronchodilators are currently available in the market; however, the usage of such medications is limited due to the potential for various adverse effects. To cope with this issue, researchers have been exploring various novel, alternative therapeutic strategies that are safe and effective to treat respiratory diseases. Several studies have been reported on the possible links between food and food-derived products in combating various chronic inflammatory diseases. Nutraceuticals are examples of such food-derived products which are gaining much interest in terms of its usage for the well-being and better human health. As a consequence, intensive research is currently aimed at identifying novel nutraceuticals, and there is an emerging notion that nutraceuticals can have a positive impact in various respiratory diseases. In this review, we discuss the efficacy of nutraceuticals in altering the various cellular and molecular mechanisms involved in mitigating the symptoms of respiratory diseases.

Pulmonary inflammation induced by low-dose particulate matter exposure in mice

Air pollution is a ubiquitous problem and comprises gaseous and particulate matter (PM). Epidemiological studies have clearly shown that exposure to PM is associated with impaired lung function and the development of lung diseases, such as chronic obstructive pulmonary disease and asthma. To understand the mechanisms involved, animal models are often used. However, the majority of such models represent high levels of exposure and are not representative of the exposure levels in less polluted countries, such as Australia. Therefore, in this study, we aimed to determine whether low dose PM₁₀ exposure has any detrimental effect on the lungs. Mice were intranasally exposed to saline or traffic-related PM₁₀ (1μg or 5μg/day) for 3 wk. Bronchoalveolar lavage (BAL) and lung tissue were analyzed. PM₁₀ at 1 μg did not significantly affect inflammatory and mitochondrial markers. At 5 μg, PM₁₀ exposure increased lymphocytes and macrophages in BAL fluid. Increased NACHT, LRR and PYD domains-containing protein 3 (NLRP3) and IL-1β production occurred following PM₁₀ exposure. PM₁₀ (5 μg) exposure reduced mitochondrial antioxidant manganese superoxide (antioxidant defense system) and mitochondrial fusion marker (OPA-1), while it increased fission marker (Drp-1). Autophagy marker light-chain 3 microtubule-associated protein (LC3)-II and phosphorylated-AMPK were reduced, and apoptosis marker (caspase 3) was increased. No significant change of remodeling markers was observed. In conclusion, a subchronic low-level exposure to PM can have an adverse effect on lung health, which should be taken into consideration for the planning of roads and residential buildings.

Doxycycline reduces the migration of tuberous sclerosis complex-2 null cells - effects on RhoA-GTPase and focal adhesion kinase

Lymphangioleiomyomatosis (LAM) is associated with dysfunction of the tuberous sclerosis complex (TSC) leading to enhanced cell proliferation and migration. This study aims to examine whether doxycycline, a tetracycline antibiotic, can inhibit the enhanced migration of TSC2-deficient cells, identify signalling pathways through which doxycycline works and to assess the effectiveness of combining doxycycline with rapamycin (mammalian target of rapamycin complex 1 inhibitor) in controlling cell migration, proliferation and wound closure. TSC2-positive and TSC2-negative mouse embryonic fibroblasts (MEF), 323-TSC2-positive and 323-TSC2-null MEF and Eker rat uterine leiomyoma (ELT3) cells were treated with doxycycline or rapamycin alone, or in combination. Migration, wound closure and proliferation were assessed using a transwell migration assay, time-lapse microscopy and manual cell counts respectively. RhoA-GTPase activity, phosphorylation of p70S6 kinase (p70S6K) and focal adhesion kinase (FAK) in TSC2-negative MEF treated with doxycycline were examined using ELISA and immunoblotting techniques. The enhanced migration of TSC2-null cells was reduced by doxycycline at concentrations as low as 20 pM, while the rate of wound closure was reduced at 2–59 μM. Doxycycline decreased RhoA-GTPase activity and phosphorylation of FAK in these cells but had no effect on the phosphorylation of p70S6K, ERK1/2 or AKT. Combining doxycycline with rapamycin significantly reduced the rate of wound closure at lower concentrations than achieved with either drug alone. This study shows that doxycycline inhibits TSC2-null cell migration. Thus doxycycline has potential as an anti-migratory agent in the treatment of diseases with TSC2 dysfunction.

Airway smooth muscle CXCR3 ligand production: regulation by JAK-STAT1 and intracellular Ca²⁺

In asthma, airway smooth muscle (ASM) chemokine (C-X-C motif) receptor 3 (CXCR3) ligand production may attract mast cells or T lymphocytes to the ASM, where they can modulate ASM functions. In ASM cells (ASMCs) from people with or without asthma, we aimed to investigate JAK-STAT1, JNK, and Ca²⁺ involvement in chemokine (C-X-C motif) ligand (CXCL)10 and CXCL11 production stimulated by interferon-γ, IL-1β, and TNF-α combined (cytomix). Confluent, growth-arrested ASMC were treated with inhibitors for pan-JAK (pyridone-6), JAK2 (AG-490), JNK (SP-600125), or the sarco(endo)plasmic reticulum Ca²⁺ATPase (SERCA) pump (thapsigargin), Ca²⁺ chelator (BAPTA-AM), or vehicle before and during cytomix stimulation for up to 24 h. Signaling protein activation as well as CXCL10/CXCL11 mRNA and protein production were examined using immunoblot analysis, real-time PCR, and ELISA, respectively. Cytomix-induced STAT1 activation was lower and CXCR3 ligand mRNA production was more sensitive to pyridone-6 and AG-490 in asthmatic than nonasthmatic ASMCs, but CXCL10/CXCL11 release was inhibited by the same proportion. Neither agent caused additional inhibition of release when used in combination with the JNK inhibitor SP-600125. Conversely, p65 NF-κB activation was higher in asthmatic than nonasthmatic ASMCs. BAPTA-AM abolished early CXCL10/CXCL11 mRNA production, whereas thapsigargin reduced it in asthmatic cells and inhibited CXCL10/CXCL11 release by both ASMC types. Despite these inhibitory effects, neither Ca²⁺ agent affected early activation of STAT1, JNK, or p65 NF-κB. In conclusion, intracellular Ca²⁺ regulated CXCL10/CXCL11 production but not early activation of the signaling molecules involved. In asthma, reduced ASM STAT1-JNK activation, increased NF-κB activation, and altered Ca²⁺ handling may contribute to rapid CXCR3 ligand production and enhanced inflammatory cell recruitment.

Doxycycline inhibits matrix metalloproteinase-2 secretion from TSC2-null mouse embryonic fibroblasts and lymphangioleiomyomatosis cells

BACKGROUND AND PURPOSE

Lymphangioleiomyomatosis (LAM) is characterized by the abnormal growth of smooth muscle-like cells (LAM cells) and cystic destruction of the lung parenchyma. LAM cell-derived matrix metalloproteinases (MMPs) are thought to play a prominent role in the tissue destruction. The aim of this study was to determine whether doxycycline, a known MMP inhibitor, can inhibit LAM cell proliferation or mitochondrial function and/or modulate MMPs and their tissue inhibitors (TIMPs).

EXPERIMENTAL APPROACH

Wild-type and tuberous sclerosis complex-2 (TSC2)-null mouse embryonic fibroblasts (MEFs) were cultured in DMEM containing 10% fetal bovine serum (FBS). Human LAM cells were derived from the lungs of LAM patients and airway smooth muscle cells from control subjects. Cells were stimulated with FBS with or without doxycycline for up to 9 days. Proliferation was assessed by manual cell counts and MTT assay, MMP production by zymography and ELISA, and TIMP production using elisa.

KEY RESULTS

Doxycycline did not change FBS-induced proliferation in MEFs or human cells. However, doxycycline did reduce metabolic activity of both wild-type and TSC2-null MEFs and LAM cells, but had no effect on control cells. Furthermore, doxycycline reduced MMP-2 from MEFs and decreased active-MMP-2 from LAM cells but had no effect on TIMP-1 and TIMP-2 from human LAM cells.

CONCLUSIONS AND IMPLICATIONS

Doxycycline decreased MMP levels and cell metabolic activity, which raises the possibility of therapeutic efficacy in LAM.

CD40 and OX40 ligand are differentially regulated on asthmatic airway smooth muscle

BACKGROUND

CD40 and OX40 Ligand (OX40L) are cell-surface molecules expressed on airway smooth muscle (ASM) that can enhance inflammatory cell activation and survival. The aim of this study was to examine the effect of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on ASM CD40 and OX40L expression.

METHODS

CD40 and OX40L expression on human ASM cells from asthmatic and nonasthmatic donors following stimulation with TNF-alpha and/or IFN-gamma was measured using cell-surface enzyme-linked immunosorbent assay (ELISA) and flow cytometry. Involvement of signalling pathway was investigated with pharmacological inhibitors. Soluble TNF receptor levels were quantified by ELISA.

RESULTS

Interferon-gamma and TNF-alpha synergistically increased CD40 expression to a greater extent on asthmatic than on nonasthmatic ASM. In contrast, IFN-gamma reduced TNF-alpha-induced OX40L expression to a similar extent in both cell types. TNF-alpha and IFN-gamma induced CD40 via nuclear factor-kappaB (NF-kappaB) and signal transducer and activator of transcription-3 in both cell types and modulated OX40L via NF-kappaB and c-Jun N terminal kinase in nonasthmatic cells. Similar effects on the induction of OX40L in asthmatic cells were seen with NF-kappaB, but these were not statistically significant. The reduced OX40L expression with TNF-alpha and IFN-gamma involved extracellular regulated kinase 1/2 activation.

CONCLUSION

Asthmatic ASM may modulate airway inflammation locally by increasing CD40 and OX40L expression in response to cytokines. IFN-gamma may regulate ASM pro-inflammatory actions by differentially modulating ASM CD40 and OX40L expression.

Dimethylfumarate inhibits NF-{kappa}B function at multiple levels to limit airway smooth muscle cell cytokine secretion

The antipsoriatic dimethylfumarate (DMF) has been anecdotically reported to reduce asthma symptoms and to improve quality of life of asthma patients. DMF decreases the expression of proinflammatory mediators by inhibiting the transcription factor NF-kappaB and might therefore be of interest for the therapy of inflammatory lung diseases. In this study, we determined the effect of DMF on platelet-derived growth factor (PDGF)-BB- and TNFalpha-induced asthma-relevant cytokines and NF-kappaB activation by primary human asthmatic and nonasthmatic airway smooth muscle cells (ASMC). Confluent nonasthmatic and asthmatic ASMC were incubated with DMF (0.1-100 microM) and/or dexamethasone (0.0001-0.1 microM), NF-kappaB p65 siRNA (100 nM), the NF-kappaB inhibitor helenalin (1 microM) before stimulation with PDGF-BB or TNFalpha (10 ng/ml). Cytokine release was measured by ELISA. NF-kappaB, mitogen and stress-activated kinase (MSK-1), and CREB activation was determined by immunoblotting and EMSA. TNFalpha-induced eotaxin, RANTES, and IL-6 as well as PDGF-BB-induced IL-6 expression was inhibited by DMF and by dexamethasone from asthmatic and nonasthmatic ASMC, but the combination of both drugs showed no glucocorticoid sparing effect in either of the two groups. NF-kappaB p65 siRNA and/or the NF-kappaB inhibitor helenalin reduced PDGF-BB- and TNFalpha-induced cytokine expression, suggesting the involvement of NF-kappaB signaling. DMF inhibited TNFalpha-induced NF-kappaB p65 phosphorylation, NF-kappaB nuclear entry, and NF-kappaB-DNA complex formation, whereas PDGF-BB appeared not to activate NF-kappaB within 60 min. Both stimuli induced the phosphorylation of MSK-1, NF-kappaB p65 at Ser276, and CREB, and all were inhibited by DMF. These data suggest that DMF downregulates cytokine secretion not only by inhibiting NF-kappaB but a wider range of NF-kappaB-linked signaling proteins, which may explain its potential beneficial effect in asthma.

Rhinovirus exposure impairs immune responses to bacterial products in human alveolar macrophages

BACKGROUND

Rhinovirus infection is responsible for considerable morbidity and mortality as the major cause of exacerbations of asthma, and is also known to induce exacerbations of cystic fibrosis and chronic obstructive pulmonary disease. Exacerbations of these diseases are also frequently associated with bacterial and atypical bacterial infection. Alveolar macrophages are the major immune cells in the airways and are important in defence against bacterial infections.

METHODS

The authors investigated whether rhinovirus modifies cytokine release, the pattern recognition receptor expression and phagocytosis by human alveolar macrophages in response to bacterial products.

RESULTS

Viable rhinovirus was detected in macrophages up to 3 days after exposure and viral RNA expression persisted for 10 days. Infectious but not UV inactivated rhinovirus increased tumour necrosis factor alpha (TNFalpha) and interleukin (IL)8 release by macrophages. In contrast, infectious rhinovirus impaired lipopolysaccharide and lipoteichoic acid induced TNFalpha and IL8 secretion by macrophages. Rhinovirus induced impairment of macrophage antibacterial immune responses did not involve IL10, prostaglandin E(2) or downregulation of Toll-like receptor 2. Furthermore, the macrophage phagocytic response to labelled bacterial particles, but not to latex beads, was impaired.

CONCLUSION

The authors have identified impairment of cytokine responses to bacterial lipopolysaccharide and lipoteichoic acid by alveolar macrophages in response to infectious rhinovirus. Virus induced impairment of antibacterial host defence has important implications in the pathogenesis of exacerbations of respiratory diseases.

In vitro studies of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is associated with abnormal airway smooth muscle that leads to the characteristic pathology of lung nodule formation and destruction of lung tissue. The current authors have previously identified abnormal behaviour of airway smooth muscle cells from patients with asthma. In this study, cells and tissue sections derived from patients with LAM (n=7), asthma (n=8), and nonasthmatic controls (n=9) were compared. The presence of the antigen human melanosome (HM)B-45 was investigated, along with the proliferation and release of extracellular matrix proteins, release of endogenous prostaglandin E2 (PGE2), vascular endothelial growth factor and connective tissue growth factor, and the expression of integrins. Positive HMB-45 staining was found in all LAM patients and no controls. Proliferation of LAM cells was not different from control cells nor was its inhibition by beta-agonists, corticosteroids, rapamycin or PGE2. However, endogenous PGE2 levels were markedly decreased in LAM cells, and this was associated with decreased expression of the inducible form of cyclooxygenase (COX-2). The increased levels of connective tissue growth factor seen in asthma cells were not observed in LAM. Elastin mRNA in response to transforming growth factor-beta stimulation was markedly lower in LAM cells than either asthma or control cells. In conclusion, lymphangioleiomyomatosis cells exhibit abnormal properties in vitro that may contribute to pathophysiology and symptomatology in patients with lymphangioleiomyomatosis.