Resveratrol inhibits transforming growth factor-β-induced proliferation and differentiation of ex vivo human lung fibroblasts into myofibroblasts through ERK/Akt inhibition and PTEN restoration

The authors investigated the role of resveratrol (RV), a natural poliphenolic molecule with several biological activities, in transforming growth factor-β (TGF-β)-induced proliferation and differentiation of ex vivo human pulmonary fibroblasts into myofibroblasts. The effects of RV treatment were evaluated by analyzing TGF-β-induced α-smooth muscle actin (α-SMA) expression and collagen production, as well as cell proliferation of both normal and idiopathic pulmonary fibrosis (IPF) lung fibroblasts. Results demonstrate that RV inhibits TGF-β-induced cell proliferation of both normal and pathological lung fibroblasts, attenuates α-SMA expression at both the mRNA and protein levels, and also inhibits intracellular collagen deposition. In order to understand the molecular mechanisms, the authors also investigated the effects of RV treatment on signaling pathways involved in TGF-β-induced fibrosis. The authors show that RV inhibited TGF-β-induced phosphorylation of both extracellular signal-regulated kinases (ERK1/2) and the serine/threonine kinase, Akt. Moreover, RV treatment blocked the TGF-β-induced decrease in phosphatase and tensin homolog (PTEN) expression levels.

Reactive oxygen species are required for maintenance and differentiation of primary lung fibroblasts in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal illness whose pathogenesis remains poorly understood. Recent evidence suggests oxidative stress as a key player in the establishment/progression of lung fibrosis in animal models and possibly in human IPF. The aim of the present study was to characterize the cellular phenotype of fibroblasts derived from IPF patients and identify underlying molecular mechanisms.

METHODOLOGY/PRINCIPAL FINDINGS

We first analyzed the baseline differentiation features and growth ability of primary lung fibroblasts derived from 7 histology proven IPF patients and 4 control subjects at different culture passages. Then, we focused on the redox state and related molecular pathways of IPF fibroblasts and investigated the impact of oxidative stress in the establishment of the IPF phenotype. IPF fibroblasts were differentiated into alpha-smooth muscle actin (SMA)-positive myofibroblasts, displayed a pro-fibrotic phenotype as expressing type-I collagen, and proliferated lower than controls cells. The IPF phenotype was inducible upon oxidative stress in control cells and was sensitive to ROS scavenging. IPF fibroblasts also contained large excess of reactive oxygen species (ROS) due to the activation of an NADPH oxidase-like system, displayed higher levels of tyrosine phosphorylated proteins and were more resistant to oxidative-stress induced cell death. Interestingly, the IPF traits disappeared with time in culture, indicating a transient effect of the initial trigger.

CONCLUSIONS/SIGNIFICANCE

Robust expression of α-SMA and type-I collagen, high and uniformly-distributed ROS levels, resistance to oxidative-stress induced cell death and constitutive activation of tyrosine kinase(s) signalling are distinctive features of the IPF phenotype. We suggest that this phenotype can be used as a model to identify the initial trigger of IPF.

Idiopathic pulmonary fibrosis: a disease with similarities and links to cancer biology

Several clinical trials have recently targeted specific pathways implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, IPF remains plagued by a median survival of 3 yrs and emphasises the need for further research with new insights and perspectives. The prevailing pathogenic hypotheses assume that either an inflammatory process or an independent epithelial/fibroblastic disorder may propagate the disease process. Based on knowledge developed with considerable scientific evidence, we provide our perspectives with an alternative point of view that IPF be considered as a neoproliferative disorder of the lung. Genetic alterations, response to growth and inhibitory signals, resistance to apoptosis, myofibroblast origin and behaviour, altered cellular communications, and intracellular signalling pathways are all fundamental pathogenic hallmarks of both IPF and cancer. The concept of IPF as a lethal malignant disorder of the lung might extend beyond the pathogenic link between these two diseases and disclose new pathogenic mechanisms leading to novel therapeutic options, adopted from cancer biology. Moreover, this vision might dawn the awareness of the public, political and scientific community of this devastating disease from an angle different from the current perception and provoke new ideas and studies to get a better understanding to control the otherwise relentless progressive disease.

Circulating fibrocytes as a marker of liver fibrosis in chronic hepatitis C

Surrogate markers of liver fibrosis are needed as an alternative to liver biopsy, which is invasive and life-threatening. Peripheral blood fibrocytes (PBF) are considered to be involved in systemic fibrogenic processes. We measured the level of PBF in patients with chronic hepatitis C by enrolling 70 patients affected with chronic hepatitis C, 20 patients with HCV-positive decompensated cirrhosis and 30 healthy volunteers. All patients underwent liver biopsy and Fibroscan for fibrosis assessment. Patients with chronic hepatitis C had significantly higher levels of PBF in comparison with healthy individuals and decompensated cirrhotics. Patients in the F0-F1 stage had a percentage of PBF of 23.3+/-4%, significantly lower (p<0.001) than in F2 and F3 stages. Patients in the F4 stage had a PBF rate of 50.6+/-2% (p<0.001 versus the F0, F1 and F2 stages). The percentage of PBF correlated positively with the Metavir score and the liver stiffness as measured by Fibroscan. PBF are increased in patients with HCV infection and correlate with the histological stage of liver fibrosis.

Acute additive effect of montelukast and beclomethasone on AMP induced bronchoconstriction

Bronchial hyperresponsiveness to 5-adenosine mono-phosphate (AMP) is a marker of airway inflammation. Inhaled corticosteroids and antileukotrienes are used as anti-inflammatory drugs for the treatment of asthma. To find out if these two drugs exert their protection in an additive fashion, we compared the effects of acute treatment with inhaled beclomethasone (BDP) and montelukast (ML), alone or in combination, on methacholine and AMP induced bronchoconstriction. 15 asthmatic patients undertook methacholine and AMP challenges at baseline and after receiving ML or BDP, alone or in combination, in a randomized, double-blind, double-dummy placebo-controlled, crossover design. BDP pretreatment significantly increased the AMP PC(20) value (68.34+/-15.9mg/mL) as compared to placebo (22.87+/-5.7mg/mL). Combined treatment, BDP plus ML, afforded a further significant increase of AMP PC(20) (154.57+/-55.0mg/mL) as compared to each single treatment. The significant protection exerted by combined treatment as compared to each single active treatment was also demonstrated by the change of AMP PC(20) doubling dose as compared to placebo and each single active treatment. Our findings suggest that these two agents exert their acute additive protection against AMP induced bronchoconstriction acting on distinct inflammatory pathways and their combined use might provide greater protection against inflammatory response elicited by AMP than either drug alone.

16,16-Dimethyl prostaglandin E2 efficacy on prevention and protection from bleomycin-induced lung injury and fibrosis

In this study, we evaluated the protective effect and therapeutic potential of the prostaglandin E(2) (PGE(2)) synthetic analog 16,16-dimethyl-PGE(2) (dmPGE(2)) in the animal model of pulmonary fibrosis induced by bleomycin. Mice subjected to intratracheal administration of bleomycin (1 mg/kg) received a dmPGE(2) dose of 30 microg/kg/day by continuous subcutaneous infusion. Bronchoalveolar lavage (BAL); immunohistochemical analysis for IL-1, TNF-alpha, and nitrotyrosine; measurement of fluid content in lung; myeloperoxidase activity assay; and lung histology were performed 1 week later. Lung histology and Sircol assay for collagen deposition were performed 3 weeks after treatments. Changes of body weight and survival rate were also evaluated at 1 and 3 weeks. Compared with bleomycin-treated mice, dmPGE(2) co-treated mice exhibited a reduced degree of body weight loss and mortality rate as well as of lung damage and inflammation, as shown by the significant reduction of: (1) lung infiltration by leukocytes; (2) myeloperoxidase activity; (3) IL-1, TNF-alpha, and nitrotyrosine immunostaining; (4) lung edema; and (5) histologic evidence of lung injury and collagen deposition. In a separate set of experiments, dmPGE(2) treatment was started 3 days after bleomycin administration, and the evaluation of lung damage and inflammation was assessed 4 days later. Importantly, delayed administration of dmPGE(2) also was able to protect from inflammation and lung injury induced by bleomycin. These results, indicating that dmPGE(2) is able to prevent and to reduce bleomycin-induced lung injury through its regulatory and anti-inflammatory properties, encourage further research to find new options for the treatment of pulmonary fibrosis.

Interleukin-6 receptor superantagonist Sant7 inhibits TGF-beta-induced proliferation of human lung fibroblasts

OBJECTIVES

Both interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta) are crucially involved in fibrotic events that characterize interstitial lung diseases (ILD). Therefore, the aim of this study was to investigate in primary cultures of normal and fibrotic human lung fibroblasts (HLF), exposed to either IL-6 or TGF-beta1, the effects on phosphorylation of mitogen-activated protein kinases (MAPK) and cell growth of IL-6 signalling inhibition, performed by the IL-6 receptor superantagonist Sant7.

MATERIALS AND METHODS

MAPK phosphorylation was detected by Western blotting, HLF viability and proliferation were evaluated using the trypan blue staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, respectively.

RESULTS

Sant7, at a concentration of 1 microg/mL, was capable of significantly inhibiting HLF proliferation and MAPK phosphorylation induced by cell exposure to IL-6 (100 ng/mL) or TGF-beta1 (10 ng/mL), whose actions were more evident in fibrotic cells.

CONCLUSIONS

These findings suggest that, in HLFs derived from patients with ILDs, the proliferative mechanisms activated by TGF-beta1 are at least in part mediated by an increased release of IL-6, leading to phosphorylation-dependent MAPK activation. Such preliminary findings may thus open new therapeutic perspectives for fibrogenic ILDs, based on inhibition of signal transduction pathways stimulated by the IL-6 receptor.

Subsegmental pulmonary embolism: value of thoracic ultrasound for diagnosis and follow-up

Timely diagnosis of pulmonary embolism (PE) is crucial because prompt appropriate management can decrease mortality and morbidity. However, the diagnosis of PE is often a challenge because of aspecific clinical presentation and the lack of a single non-invasive diagnostic test sufficiently sensitive for the diagnosis in all suspected cases. The present report describes a 37-year-old woman in whom diagnosis of recurrent subsegmental PE was achieved through subtle integration of imaging techniques including thoracic ultrasound (TUS) that was demonstrated to be of valuable usefulness. We think that TUS may represent an adjunctive technique for diagnosing PE.

A case of pulmonary Langerhans cell histiocytosis in a young woman with coeliac disease

Pulmonary Langerhans cells histiocytosis (pulmonary LCH) is an idiopathic unusual lung disease and its association with other systemic diseases has been rarely observed. Here, we describe a young non-smoking woman with concomitant pulmonary LCH and coeliac disease that, despite therapy, suddenly deteriorated. To the best of the authors' knowledge, this is the first report in the medical literature describing an association of coeliac disease with pulmonary LCH. Considering the concomitant occurrence of both diseases in our patient and the severe course of pulmonary LCH observed, we hypothesise that coeliac disease and pulmonary LCH might be related by a common disturbance in immunity and the onset and/or the course of pulmonary LCH could be influenced or markedly worsened by the presence of coeliac disease.

A case of pulmonary Langerhans cell histiocytosis in a young woman with coeliac disease

Pulmonary Langerhans cells histiocytosis (pulmonary LCH) is an idiopathic unusual lung disease and its association with other systemic diseases has been rarely observed. Here, we describe a young non-smoking woman with concomitant pulmonary LCH and coeliac disease that, despite therapy, suddenly deteriorated. To the best of the authors' knowledge, this is the first report in the medical literature describing an association of coeliac disease with pulmonary LCH. Considering the concomitant occurrence of both diseases in our patient and the severe course of pulmonary LCH observed, we hypothesise that coeliac disease and pulmonary LCH might be related by a common disturbance in immunity and the onset and/or the course of pulmonary LCH could be influenced or markedly worsened by the presence of coeliac disease.

Cellular and molecular effects of protons: apoptosis induction and potential implications for cancer therapy

Due to their ballistic precision, apoptosis induction by protons could be a strategy to specifically eliminate neoplastic cells. To characterize the cellular and molecular effects of these hadrons, we performed dose-response and time-course experiments by exposing different cell lines (PC3, Ca301D, MCF7) to increasing doses of protons and examining them with FACS, RT-PCR, and electron spin resonance (ESR). Irradiation with a dose of 10 Gy of a 26,7 Mev proton beam altered cell structures such as membranes, caused DNA double strand breaks, and significantly increased intracellular levels of hydroxyl ions, are active oxygen species (ROS). This modified the transcriptome of irradiated cells, activated the mitochondrial (intrinsic) pathway of apoptosis, and resulted in cycle arrest at the G2/M boundary. The number of necrotic cells within the irradiated cell population did not significantly increase with respect to the controls. The effects of irradiation with 20 Gy were qualitatively as well as quantitatively similar, but exposure to 40 Gy caused massive necrosis. Similar experiments with photons demonstrated that they induce apoptosis in a significantly lower number of cells and in a temporally delayed manner. These data advance our knowledge on the cellular and molecular effects of proton irradiation and could be useful for improving current hadrontherapy protocols.

CCR5 and CCR3 expression on T CD3+ lymphocytes from HIV/Leishmania co-infected subjects

CC chemokine receptor 5 (CCR5) and CC chemokine receptor 3 (CCR3) are membrane-bound proteins involved in HIV-1 entry into susceptible cells. All T lymphocyte subsets display CCR5 and CCR3 on their membrane surface. T helper 1 cells are known to express CCR5 but not CCR3, and most of T cells expressing CCR3 are T helper 2. This study aimed to assess the expression of CCR5 and CCR3 on peripheral blood CD3+ T lymphocytes of HIV-Leishmania co-infected individuals. A total of 36 subjects were enrolled; nine had HIV-Leishmania co-infection; nine were HIV-infected without Leishmania, nine had visceral leishmaniasis without HIV co-infection and nine were healthy blood donors. HIV-Leishmania co-infected subjects showed a significantly higher rate of CCR5+CD3+ T lymphocytes in comparison with the other studied groups. The higher rate of CD3+ T-cells expressing CCR5 found in HIV-Leishmania co-infected subjects may be related to the role of Leishmania as an enhancer of the progression to AIDS.

Activation of cytosolic phospholipase A2 and 15-lipoxygenase by oxidized low-density lipoproteins in cultured human lung fibroblasts

In cell cultures of human lung fibroblasts, we found that oxidized LDL (oxLDL), after 24-h treatment, stimulated arachidonic acid release. A putative role for phospholipases A(2) and MAPK activities in this process was postulated. Consequently, we studied the contribution of either Ca(2+)-dependent, cytosolic phospholipase A(2) (cPLA(2)) or Ca(2+)-independent phospholipase A(2) (iPLA(2)), and the role of the MAP kinase family in oxLDL toxicity to fibroblastic cells in vitro. Activation of extracellular signal-regulated kinases ERK1/2, p38 and c-Jun NH(2)-terminal kinase (JNK) was also assessed with Western blotting. Compared with cellular samples untreated or treated with native LDL, treatment with oxLDL (50-100 microM hydroperoxides) for 24 h significantly increased the levels of either cPLA(2) protein expression or constitutively phosphorylated cPLA(2) protein; in addition we observed enzyme translocation to membranes. iPLA(2) activity was not stimulated by oxLDL. Arachidonic acid release appeared to be associated with phosphorylation of ERK1/2 which was significantly enhanced in a dose-dependent manner whereas no activation of p38 and JNKs was found, indicating that these MAPKs are not involved in mediating the maximal oxLDL response. Western blotting on subcellular fractions and confocal microscopy analyses confirmed an increase in 15-lipoxygenase (15-LO) protein expression and translocation upon activation. A significant increase of cyclooxygenase-2 expression into membrane fraction was also found. Collectively, the data presented link the stimulation of ERK-cPLA(2)-15-LO pathway by oxLDL to the prooxidant mechanism of the lipoprotein complex. It may initially stimulate the fibroblast reaction against the oxidation challenge as well as metabolic repair, such as during lung inflammation and pulmonary fibrosis.

Exhaled bronchial cysteinyl leukotrienes in allergic patients

PURPOSE OF REVIEW

To review the current knowledge of noninvasive monitoring of allergic airway inflammation by analysis of leukotrienes in the exhaled breath condensate.

RECENT FINDINGS

Treatment of respiratory allergies involves chronic treatment based on clinical symptoms and pulmonary function tests. Evaluation of local inflammation would be desirable but is currently not feasible because of the difficulty in sampling the airways. Recently, exhaled breath condensate collection and analysis has polarized much interest in the respiratory field. Although some methodological issues are still under scrutiny, airways inflammatory markers can be assayed with this technique. In particular, exhaled breath condensate leukotrienes have been thoroughly investigated in the setting of bronchial asthma and allergic rhinitis in adults and children. Exhaled leukotrienes are increased in patients with asthma and rhinitis during the pollen season, correlate with exacerbations and asthma severity, and are reduced by specific anti-inflammatory treatment and allergen avoidance.

SUMMARY

Some issues still prevent the use of exhaled breath condensate in clinical practice but in the research setting it has been proved to be useful for noninvasive monitoring of allergic inflammation in the lung. In particular, exhaled leukotrienes may represent valuable biomarkers for diagnostic and therapeutic purposes in allergic patients.

Protective effect of orally administered carnosine on bleomycin-induced lung injury

Carnosine is an endogenously synthesized dipeptide composed of beta-alanine and L-histidine. It acts as a free radical scavenger and possesses antioxidant properties. Carnosine reduces proinflammatory and profibrotic cytokines such as transforming growth factor-beta (TGF-beta), IL-1, and TNF-alpha in different experimental settings. In the present study, we investigated the efficacy of carnosine on the animal model of bleomycin-induced lung injury. Mice were subjected to intratracheal administration of bleomycin and were assigned to receive carnosine daily by an oral bolus of 150 mg/kg. One week after fibrosis induction, bronchoalveolar lavage (BAL) cell counts and TGF-beta levels, lung histology, and immunohistochemical analyses for myeloperoxidase, TGF-beta, inducible nitric oxide synthase, nitrotyrosine, and poly(ADP-ribose) polymerase were performed. Finally, apoptosis was quantified by terminal deoxynucleotidyltransferase-mediated UTP end-labeling assay. After bleomycin administration, carnosine-treated mice exhibited a reduced degree of lung damage and inflammation compared with wild-type mice, as shown by the reduction of 1) body weight, 2) mortality rate, 3) lung infiltration by neutrophils (myeloperoxidase activity and BAL total and differential cell counts), 4) lung edema, 5) histological evidence of lung injury and collagen deposition, 6) lung myeloperoxidase, TGF-beta, inducible nitric oxide synthase, nitrotyrosine, and poly(ADP-ribose) polymerase immunostaining, 7) BAL TGF-beta levels, and 8) apoptosis. Our results indicate that orally administered carnosine is able to prevent bleomycin-induced lung injury likely through its direct antioxidant properties. Carnosine is already available for human use. It might prove useful as an add-on therapy for the treatment of fibrotic disorders of the lung where oxidative stress plays a role, such as for idiopathic pulmonary fibrosis, a disease that still represents a major challenge to medical treatment.

Astrocyte-like cells as a main target for estrogen action during neuronal differentiation

Neurospheres from the subventricular zone of adult mice were used as an experimental model to analyse the early differential effects of 17beta-estradiol (17beta-E2). Both floating and differentiating neurospheres expressed estrogen receptors (ERs) alpha and beta. The initial phases of differentiation coincided with a peak of ERalpha expression as by Western blot analysis. Treatment with 10 nM 17beta-E2 induced a significant increase in the glial fibrillary acidic protein (GFAP)-positive population and a greater expression of GFAP, an effect sensitive to the estrogen receptor antagonist ICI 182,780. The GFAP-positive cell population induced by 17beta-E2 was characterized by a highly differentiated phenotype and intense immunostaining as by immunocytochemistry and flow cytometry. These cells co-expressed ERalpha and were positive to BrdU. 17beta-E2 also affected neuronal differentiation by rapidly and transiently increasing the percentage of polysialylated-neural cell adhesion molecule (PSA-NCAM)-positive progenitors, and by accelerating the appearance of a mature neuronal phenotype, as evaluated by microtubule-associated protein 2 (MAP2) staining. Our results point to a key role for ERalpha during initial phases of differentiation of brain cells and to an effect of 17beta-E2 that sequentially involves both glia and neurons.

Pharmacological inhibition of leukotrienes in an animal model of bleomycin-induced acute lung injury

Leukotrienes are increased locally in idiopathic pulmonary fibrosis. Furthermore, a role for these arachidonic acid metabolites has been thoroughly characterized in the animal bleomycin model of lung fibrosis by using different gene knock-out settings.

We investigated the efficacy of pharmacological inhibition of leukotrienes activity in the development of bleomycin-induced lung injury by comparing the responses in wild-type mice with mice treated with zileuton, a 5-lipoxygenase inhibitor and MK-571, a cys-leukotrienes receptor antagonist.

Mice were subjected to intra-tracheal administration of bleomycin or saline and were assigned to receive either MK-571 at 1 mg/Kg or zileuton at 50 mg/Kg daily. One week after bleomycin administration, BAL cell counts, lung histology with van Gieson for collagen staining and immunohistochemical analysis for myeloperoxidase, IL-1 and TNF-α were performed.

Following bleomycin administration both MK-571 and zileuton treated mice exhibited a reduced degree of lung damage and inflammation when compared to WT mice as shown by the reduction of:(i) loss of body weight, (ii) mortality rate, (iii) lung infiltration by neutrophils (myeloperoxidase activity, BAL total and differential cell counts), (iv) lung edema, (v) histological evidence of lung injury and collagen deposition, (vi) lung myeloperoxidase, IL-1 and TNF-α staining.

This is the first study showing that the pharmacological inhibition of leukotrienes activity attenuates bleomycin-induced lung injury in mice. Given our results as well as those coming from genetic studies, it might be considered meaningful to trial this drug class in the treatment of pulmonary fibrosis, a disease that still represents a major challenge to medical treatment.

Altered intercellular communication in lung fibroblast cultures from patients with idiopathic pulmonary fibrosis

Rationale

Gap junctions are membrane channels formed by an array of connexins which links adjacent cells realizing an electro- metabolic synapse. Connexin-mediated communication is crucial in the regulation of cell growth, differentiation, and development. The activation and proliferation of phenotypically altered fibroblasts are central events in the pathogenesis of idiopathic pulmonary fibrosis. We sought to evaluate the role of connexin-43, the most abundant gap-junction subunit in the human lung, in the pathogenesis of this condition.

Methods

We investigated the transcription and protein expression of connexin-43 and the gap-junctional intercellular communication (GJIC) in 5 primary lung fibroblast lines derived from normal subjects (NF) and from 3 histologically proven IPF patients (FF).

Results

Here we show that connexin-43 mRNA was significantly reduced in FF as demonstrated by standard and quantitative RT-PCR. GJIC was functionally evaluated by means of flow-cytometry. In order to demonstrate that dye spreading was taking place through gap junctions, we used carbenoxolone as a pharmacological gap-junction blocker. Carbenoxolone specifically blocked GJIC in our system in a concentration dependent manner. FF showed a significantly reduced homologous GJIC compared to NF. Similarly, GJIC was significantly impaired in FF when a heterologous NF line was used as dye donor, suggesting a complete defect in GJIC of FF.

Conclusion

These results suggest a novel alteration in primary lung fibroblasts from IPF patients. The reduced Cx43 expression and the associated alteration in cell-to-cell communication may justify some of the known pathological characteristic of this devastating disease that still represents a challenge to the medical practice.

Intranasal steroid reduces exhaled bronchial cysteinyl leukotrienes in allergic patients

BACKGROUND

Allergic rhinitis (AR) precedes and is often associated with bronchial asthma. Indeed, local and systemic inflammations in both conditions are very similar. Cysteinyl-leukotrienes (cys-LTs) are generated during early- and late-phase allergic reactions and induce smooth-muscle contraction, microvascular leakage, and mucous hypersecretion. Cys-LTs are detected in exhaled breath condensate (EBC) of asthmatics and regardless of bronchial symptoms, they are also found in EBC of rhinitic patients.

OBJECTIVE

To evaluate cys-LTs in EBC of allergic patients and to assess the activity of nasal fluticasone propionate (FP) on EBC cys-LTs levels.

METHODS

Cys-LTs coefficient of variation (CV) was evaluated from different EBC in 5 healthy volunteers. Cys-LTs levels from EBCs in 13 healthy controls and 56 allergic rhinitic (n=31) and rhinitic/asthmatic (n=25) patients were also evaluated at baseline. Subsequently patients were randomized to receive either FP 100 microg/day per nostril or placebo for 2 weeks and then re-evaluated for EBC cys-LTs.

RESULTS

The CV was 14.12%. EBC cys-LTs in allergic patients were significantly higher than in healthy subjects (70.9 vs. 20.6 pg/mL (median), P<0.05), while it did not differ between asthmatic/rhinitic and purely rhinitic patients. Treatment significantly reduced cys-LTs (from 93.6 to 19.9 pg/mL, P<0.001). This effect was evident both in asthmatic/rhinitic and in rhinitic patients.

CONCLUSION

Treatment of AR with FP significantly reduces the levels of cys-LTs, major noninvasive markers of lower airway inflammation, suggesting that upper and lower airway inflammation is present and should be thus treated as a whole in subjects with AR with and without asthma.

Endothelin-1 induces proliferation of human lung fibroblasts and IL-11 secretion through an ET(A) receptor-dependent activation of MAP kinases

Endothelin-1 (ET-1) is implicated in the fibrotic responses characterizing interstitial lung diseases, as well as in the airway remodeling process occurring in asthma. Within such a context, the aim of our study was to investigate, in primary cultures of normal human lung fibroblasts (NHLFs), the ET-1 receptor subtypes, and the intracellular signal transduction pathways involved in the proliferative effects of this peptide. Therefore, cells were exposed to ET-1 in the presence or absence of an overnight pre-treatment with either ET(A) or ET(B) selective receptor antagonists. After cell lysis, immunoblotting was performed using monoclonal antibodies against the phosphorylated, active forms of mitogen-activated protein kinases (MAPK). ET-1 induced a significant increase in MAPK phosphorylation pattern, and also stimulated fibroblast proliferation and IL-6/IL-11 release into cell culture supernatants. All these effects were inhibited by the selective ET(A) antagonist BQ-123, but not by the specific ET(B) antagonist BQ-788. The stimulatory influence of ET-1 on IL-11, but not on IL-6 secretion, was prevented by MAPK inhibitors. Therefore, such results suggest that in human lung fibroblasts ET-1 exerts a profibrogenic action via an ET(A) receptor-dependent, MAPK-mediated induction of IL-11 release and cell proliferation.

Effects of TGF-β and glucocorticoids on map kinase phosphorylation, IL-6/IL-11 secretion and cell proliferation in primary cultures of human lung fibroblasts

Transforming growth factor-beta1 (TGF-beta1) is crucially involved in the fibrotic events characterizing interstitial lung diseases (ILDs), as well as in the airway remodeling process typical of asthma. Within such a context, the aim of our study was to investigate, in primary cultures of normal and fibrotic human lung fibroblasts (HLFs), the effects of TGF-beta1 on mitogen-activated protein kinase (MAPK) phosphorylation, cell proliferation, and production of interleukins 6 (IL-6) and 11 (IL-11), in the presence or absence of a pretreatment with budesonide (BUD). MAPK phosphorylation was detected by Western blotting, cell viability and proliferation were evaluated using Trypan blue staining and [(3)H]-thymidine incorporation assay, respectively, and the release of IL-6 and IL-11 into cell culture supernatants was assessed by ELISA. TGF-beta1 (10 ng/ml) significantly stimulated MAPK phosphorylation (P < 0.01), and also enhanced cell proliferation as well as the secretion of both IL-6 and IL-11, which reached the highest increases at the 72nd h of cell exposure to this growth factor. All such effects were prevented by BUD (10(-8) M) and, with the exception of IL-6 release, also by a mixture of MAPK inhibitors. Therefore, our findings suggest that the fibrotic action exerted by TGF-beta1 in the lung is mediated at least in part by MAPK activation and by an increased synthesis of the profibrogenic cytokines IL-6 and IL-11; all these effects appear to be prevented by corticosteroids via inhibition of MAPK phosphorylation.

The p53-homologue p63 may promote thyroid cancer progression

Inactivation of p53 and p73 is known to promote thyroid cancer progression. We now describe p63 expression and function in human thyroid cancer. TAp63alpha is expressed in most thyroid cancer specimens and cell lines, but not in normal thyrocytes. However, in thyroid cancer cells TAp63alpha fails to induce the target genes (p21Cip1, Bax, MDM2) and, as a consequence, cell cycle arrest and apoptosis occur. Moreover, TAp63alpha antagonizes the effect of p53 on target genes, cell viability and foci formation, and p63 gene silencing by small interfering (si) RNA results in improved p53 activity. This unusual effect of TAp63alpha depends on the protein C-terminus, since TAp63beta and TAp63gamma isoforms, which have a different arrangement of their C-terminus, are still able to induce the target genes and to exert tumour-restraining effects in thyroid cancer cells. Our data outline the existence of a complex network among p53 family members, where TAp63alpha may promote thyroid tumour progression by inactivating the tumour suppressor activity of p53.

Bradykinin differentiates human lung fibroblasts to a myofibroblast phenotype via the B2 receptor

BACKGROUND

The identification of factors mediating the transition of lung fibroblasts into myofibroblasts is considered fundamental in the comprehension of abnormal reparative processes. Bradykinin, a mediator known for its proinflammatory action, is able to induce cytokine production and contractility in fibroblast cultures.

OBJECTIVES

In this study the ability of bradykinin to drive fibroblast into a myofibroblast phenotype at the cellular and molecular level was evaluated.

METHODS

alpha-Smooth muscle actin (alpha-SMA) expression and TGF-beta in bradykinin stimulated fibroblasts were tested by means of flow cytometry, Western blot, and RT-PCR. Cell proliferation and collagen production were evaluated by the colorimetric methylthiazol tetrazolium assay and sirius red assay, respectively. Which bradykinin receptor mediates the expression of alpha-SMA was evaluated using selective B1 and B2 blocking agents. Furthermore, the effect of bradykinin on extracellular signal-regulated kinase 1/2 phosphorylation was explored.

RESULTS

Bradykinin caused in lung fibroblasts a significant increase in alpha-SMA at the cellular and molecular level. The B2 receptor was held responsible for this effect because a specific receptor antagonist had entirely blocked this effect. Bradykinin was able to induce fibroblast proliferation and collagen production. Bradykinin significantly activated mitogen-activated protein kinase pathway by phosphorylating extracellular signal-regulated kinase 1/2, whereas PD98059, a specific inhibitor, was able to block myofibroblast induction. Although bradykinin induced an increase of TGF-beta on fibroblasts, the blockage of this cytokine did not alter alpha-SMA expression.

CONCLUSION

The data support the hypothesis that bradykinin may be involved in bronchial remodeling and lung fibrosis beyond its well recognized proinflammatory activity, also suggesting a new potential therapeutic strategy to control altered reparatory processes.

Interaction between human lung fibroblasts and T-lymphocytes prevents activation of CD4+ cells

Background

T lymphocytes are demonstrated to play an important role in several chronic pulmonary inflammatory diseases. In this study we provide evidence that human lung fibroblasts are capable of mutually interacting with T-lymphocytes leading to functionally significant responses by T-cells and fibroblasts.

Methods

Human lung fibroblast were co-cultured with PMA-ionomycin activated T-CD4 lymphocytes for 36 hours. Surface as well as intracellular proteins expression, relevant to fibroblasts and lymphocytes activation, were evaluated by means of flow cytometry and RT-PCR. Proliferative responses of T lymphocytes to concanavalin A were evaluated by the MTT assay.

Results

In lung fibroblasts, activated lymphocytes promote an increase of expression of cyclooxygenase-2 and ICAM-1, expressed as mean fluorescence intensity (MFI), from 5.4 ± 0.9 and 0.7 ± 0.15 to 9.1 ± 1.5 and 38.6 ± 7.8, respectively. Fibroblasts, in turn, induce a significant reduction of transcription and protein expression of CD69, LFA-1 and CD28 in activated lymphocytes and CD3 in resting lymphocytes. In activated T lymphocytes, LFA-1, CD28 and CD69 expression was 16.6 ± 0.7, 18.9 ± 1.9 and 6.6 ± 1.3, respectively, and was significantly reduced by fibroblasts to 9.4 ± 0.7, 9.4 ± 1.4 and 3.5 ± 1.0. CD3 expression in resting lymphocytes was 11.9 ± 1.4 and was significantly reduced by fibroblasts to 6.4 ± 1.1. Intracellular cytokines, TNF-alpha and IL-10, were evaluated in T lymphocytes. Co-incubation with fibroblasts reduced the number of TNF-alpha positive lymphocytes from 54,4% ± 6.12 to 30.8 ± 2.8, while IL-10 positive cells were unaffected. Finally, co-culture with fibroblasts significantly reduced Con A proliferative response of T lymphocytes, measured as MTT absorbance, from 0.24 ± 0.02 nm to 0.16 ± 0.02 nm. Interestingly, while the activation of fibroblasts is mediated by a soluble factor, a cognate interaction ICAM-1 mediated was demonstrated to be responsible for the modulation of LFA-1, CD28 and CD69.

Conclusion

Findings from this study suggest that fibroblasts play a role in the local regulation of the immune response, being able to modulate effector functions of cells recruited into sites of inflammation.

The effect of fexofenadine on expression of intercellular adhesion molecule 1 and induction of apoptosis on peripheral eosinophils

The role of eosinophils in the pathogenesis of allergic disorders has been established by several studies. Recently, it has been suggested that second-generation antihistamines, widely used to relieve allergic symptoms, may have anti-inflammatory effects. To assess the possible anti-inflammatory activity of fexofenadine, a selective H1-receptor antagonist, we evaluated its capacity to modulate the expression of adhesion molecules leukocyte function-associated antigen (LFA) 1 and intracellular adhesion molecule (ICAM) 1 on eosinophil surface and to induce apoptosis of eosinophils. To analyze the expression of adhesion molecules, eosinophils from healthy donors were cultured in the presence of interferon gamma and tumor necrosis factor alpha with various concentrations of fexofenadine, incubated with monoclonal antibodies anti-ICAM-1 and LFA-1 and then analyzed by flow cytometry. To evaluate apoptosis of eosinophils, cells stimulated with interleukin-5, in the presence of different concentrations of fexofenadine, have been incubated with a phosphatidylserine-binding protein (annexin V) fluorescein isothiocyanate conjugated and then analyzed by flow cytometry. Apoptosis was evaluated as a percentage of annexin V+ cells. In this study, fexofenadine did not cause any significant changes in the expression of LFA-1 but was shown to be able to inhibit the expression of ICAM-1 at concentrations between 10(-3) and 10(-4) M. Moreover, concentrations of fexofenadine from 10(-3) to 6 x 10(-4) M induced a significant increment in the percentage of apoptotic cells. Our findings indicate the possibility of obtaining relevant anti-inflammatory pharmacologic effects, other than antihistamine activity, by fexofenadine, such as inhibition of ICAM-1 expression and induction of eosinophil apoptosis.

Progenitor cells from the adult mouse brain acquire a neuronal phenotype in response to beta-amyloid

Neurospheres from adult mouse subventricular zone (SVZ) were grown in suspension cultures for 12-15 days. Neurospheres consisted mainly of neural precursor cells (NPCs) immunoreactive for nestin and also contained nestin-negative precursors. We used these neurospheres to determine the effects of synthetic beta-amyloid fragments (both betaAP(1-42) and betaAP(25-35)) on NPC proliferation, differentiation and survival. We show that neurospheres exposed to 25 microM betaAP(25-35) or betaAP(1-42) for 24 h (a toxic condition for mature neurons) did not undergo apoptosis. Instead, betaAP(25-35) orientated nestin-negative precursors towards nestin-positive NPCs and turned nestin-positive NPCs into neuroblasts. Intracerebroventricular infusion of full-length betaAP(1-42) increased the population of PSA-NCAM-positive cells in the SVZ, without affecting proliferation. We conclude that betaAP influences the fate of progenitor cells, driving their differentiation towards a neuronal lineage.

Inhibition or knock out of inducible nitric oxide synthase result in resistance to bleomycin-induced lung injury

BACKGROUND

In the present study, by comparing the responses in wild-type mice (WT) and mice lacking (KO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the role played by iNOS in the development of on the lung injury caused by bleomycin administration. When compared to bleomycin-treated iNOSWT mice, iNOSKO mice, which had received bleomycin, exhibited a reduced degree of the (i) lost of body weight, (ii) mortality rate, (iii) infiltration of the lung with polymorphonuclear neutrophils (MPO activity), (iv) edema formation, (v) histological evidence of lung injury, (vi) lung collagen deposition and (vii) lung Transforming Growth Factor beta1 (TGF-beta1) expression.

METHODS

Mice subjected to intratracheal administration of bleomycin developed a significant lung injury. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in lungs from bleomycin-treated iNOSWT mice.

RESULTS

The intensity and degree of nitrotyrosine staining was markedly reduced in tissue section from bleomycin-iNOSKO mice. Treatment of iNOSWT mice with of GW274150, a novel, potent and selective inhibitor of iNOS activity (5 mg/kg i.p.) also significantly attenuated all of the above indicators of lung damage and inflammation.

CONCLUSION

Taken together, our results clearly demonstrate that iNOS plays an important role in the lung injury induced by bleomycin in the mice.

Effect of rosiglitazone and 15-deoxy-Delta12,14-prostaglandin J2 on bleomycin-induced lung injury

Thiazolidinedione rosiglitazone and 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), are two peroxisome proliferator-activated receptor (PPAR)-gamma ligands. The aim of this study was to investigate the effect of rosiglitazone and 15d-PGJ2 on the lung injury caused by bleomycin administration. Mice subjected to intratracheal administration of bleomycin developed significant lung injury. An increase in immunoreactivity to nitrotyrosine, poly(ADP ribose) polymerase (PARP) and inducible nitric oxide synthase as well as a significant loss of body weight and mortality was observed in the lung of bleomycin-treated mice. Administration of the two PPAR-gamma agonists rosiglitazone (10 mg x kg(-1) i.p.) and 15d-PGJ2 (30 microg x kg(-1) i.p.) significantly reduced the: 1) loss of body weight, 2) mortality rate, 3) infiltration of the lung with polymorphonuclear neutrophils (myeloperoxidase activity), 4) oedema formation, and 5) histological evidence of lung injury. Administration of rosiglitazone and 15d-PGJ2 also markedly reduced the nitrotyrosine, PARP and inducible nitric oxide synthase formation. In addition, treatment with the PPAR-gamma antagonist bisphenol A diglycidyl ether (1 mg x kg(-1) i.p. 30 min before the rosiglitazone or 15d-PGJ2) significantly antagonised the effect of the two PPAR-gamma agonists. These results demonstrate that the two peroxisome proliferator-activated receptor-gamma agonists, rosiglitazone and 15-deoxy-Delta12,14-prostaglandin J2, significantly reduce lung injury induced by bleomycin in mice.

Resveratrol and propolis as necrosis or apoptosis inducers in human prostate carcinoma cells

Vegetables and fruit help the prevention and the therapy of several kinds of cancer because they contain micronutrients, a class of substances that have been shown to exhibit chemopreventive and chemotherapeutic activities. In the present study the effects of resveratrol (100 and 200 microM), a phytoalexin found in grapes, and of the ethanolic extract of propolis (50 and 100 microg/ml), a natural honeybee hive product, were tested in androgen-resistant prostate cancer cells (DU145), a cell line resembling the last stage of prostate carcinoma. A comparison between the activity of these micronutrients and vinorelbine bitartrate (Navelbine), a semi-synthetic drug normally used in the therapy of prostate cancer, was conducted. Several biochemical parameters were tested, such as cell viability (MTT assay), cell membrane integrity (lactate dehydrogenase release), cell redox status (nitric oxide formation, reactive oxygen species production, reduced glutathione levels), genomic DNA fragmentation (COMET assay) with special attention on the presence of apoptotic DNA damage (TUNEL test), and possible mitochondrial transmembrane potential alteration (deltapsi). Our results point out the anticancer activity of resveratrol and propolis extract in human prostate cancer, exerting their cytotoxicity through two different types of cell death: necrosis and apoptosis, respectively. The data obtained suggest the possible use of these micronutrients both in alternative to classic chemotherapy, and in combination with very low dosage of vinorelbine (5 microM).

[Prevalence of respiratory symptoms, reduction in lung function and allergic sensitization in a group of traffic police officers exposed to urban pollution]

BACKGROUND

Environmental factors are believed to play a critical role in the development of allergic respiratory diseases, such as asthma and rhinitis. Particularly, the role of urban pollution in the pathogenesis of these diseases is debated.

OBJECTIVES

The aim of the study was to investigate whether subjects with a well-defined occupational history of exposure to road traffic fumes presented an increased prevalence of respiratory symptoms of chronic bronchitis (cough), asthma (wheeze), and allergic sensitisation to the most common allergens and reduced lung function compared with an unexposed control group.

METHODS

The study was conducted on 484 traffic police in Catania (465 men and 19 women), with a mean age of 45 +/- 7.9 years, who were subdivided into three groups. The first group included traffic police assigned to traffic direction, the second group included traffic police working in administrative offices, the third group included all traffic police who did not fall into the previous groups. In the first group, "truly exposed" subjects were identifed as police officers assigned to traffic direction in the last 8 years. Similarly, in the second group, "truly non-exposed" subjects were identified as police officers working in offices in the last 8 years.

RESULTS

Statistical analysis showed a significant difference in mean age between the truly exposed group and the truly non-exposed group (p < 0.01). The truly exposed group showed a greater prevalence of symptoms (cough, wheeze and dyspnoea), and positive reaction to skin allergy tests compared with the "truly non-exposed group", but this increase did not reach statistical significance. Alterations of the respiratory function tests were more frequent in the non-exposed (14.3%) compared to the exposed group (9.6%). The highest prevalence of cough, dyspnoea and wheezing was detected in smokers compared to non-smokers and to ex-smokers within each group.

CONCLUSIONS

Our results show a major prevalence of respiratory symptoms and allergic sensitisation in exposed traffic police compared with non-exposed police, although this did not reach statistical significance. Further epidemiological studies conducted on larger samples are required to better understand the role of road traffic pollution in inducing allergic respiratory diseases.

Novel neuronal targets for the acetylcholinesterase inhibitor donepezil

The effects of the acetylcholinesterase inhibitor donepezil on cell viability and proliferation events have been analysed in SH-SY5Y human neuroblastoma cells. Short- (48 h) or long-term (7 days) exposure of SH-SY5Y cells to donepezil (100 nM-10 microM) induced a concentration-dependent inhibition of cell proliferation that was not modified by muscarinic and nicotinic receptor antagonists, or mimicked by galantamine, and was not related to induction of apoptosis. By analysing the distribution profile of cell populations within the cell cycle following treatment with 10 microM donepezil, a reduction of cells in the S-G2/M phases of the cycle and a parallel increase of the G0/G1 population were observed. In addition, the expression of two cyclins of the G1/S and G2/M transitions, cyclin E and cyclin B, was significantly reduced in donepezil-treated cells. In contrast, the expression of the cell cycle inhibitor p21 rapidly (6 h) increased following exposure to the drug. Finally, donepezil increased the expression of the neuronal marker MAP-2 in selected subpopulations of SH-SY5Y cells, suggesting that the effect on cell proliferation by donepezil may correlate to a trend to neuronal differentiation.

Glia mediates the neuroprotective action of estradiol on beta-amyloid-induced neuronal death

17beta-Estradiol (17beta-E(2)) is known to exert neuroprotective activity against beta-amyloid, but its exact target and mechanism of action in this effect have not been elucidated. The involvement of astroglia in neuroprotection of 17beta-E(2) against the beta-amyloid fragment [betaAP((25-35))] has been evaluated using an experimental paradigm in which medium conditioned from rat astroglia pretreated with 17beta-E2 was transferred to pure rat cortical neurons challenged with 25 microm betaAP((25-35)) for 24 h. The toxicity of betaAP((25-35)) was assessed by flow cytometry, evaluating the ability of the peptide to induce an aberrant mitotic cell cycle in neurons. The results obtained indicate that conditioned medium from astrocytes preexposed to 17beta-E(2) for 4 h increased the viability of cortical neurons treated with betaAP((25-35)). This effect was not modified by treatment with the estrogen receptor antagonist ICI 182,780, added directly to neurons, nor was it mimicked by direct addition of 17beta-E(2) to neuronal cultures during exposure to betaAP((25-35)). A soluble factor stimulated by 17beta-E(2) seemed to be involved, and accordingly, the intracellular and released levels of TGF-beta1 were increased by 17beta-E(2) treatment, as established by Western blot analysis. In addition, the intracellular content of TGF-beta1 in immunopositive cells, as detected by flow cytometry, was reduced, suggesting that 17beta-E(2) stimulated mainly the release of the cytokine. In support of a role for TGF-beta1 in astrocyte-mediated 17beta-E(2) neuroprotective activity, incubation with a neutralizing anti-TGF-beta1 antibody significantly modified the reduction of neuronal death induced by 17beta-E(2)-treated astrocyte-conditioned medium.

Effect of immunotherapy on asthma progression, BHR and sputum eosinophils in allergic rhinitis

BACKGROUND

Bronchial hyperresponsiveness (BHR) and airway inflammation are frequently associated with allergic rhinitis, and may be important risk factors for the development of asthma. Specific immunotherapy (SIT) reduces symptom in subjects with allergic rhinitis, but the mechanisms are not clear.

AIMS OF THE STUDY

To assess the effect of Parietaria-SIT on asthma progression, rhinitic symptoms, BHR, and eosinophilic inflammation.

METHODS

Nonasthmatic subjects with seasonal rhinitis were randomly assigned to receive Parietaria pollen vaccine (n = 15) or matched placebo (n = 15). Data on symptoms and medication score, BHR to methacholine, eosinophilia in sputum were collected throughout the 3-year study.

RESULTS

By the end of the study, in the placebo group, symptoms and medication scores significantly increased by a median (interquartile range) of 121% (15-280) and 263% (0-4400) respectively (P < 0.01), whereas no significant difference was observed in the SIT group. We found no significant changes in sputum eosinophils and BHR to methacholine in both groups throughout the study. Nine of 29 participants developed asthma symptoms during the study; of these, only two subjects (14%) in the SIT-treated group (P = 0.056).

CONCLUSIONS

Parietaria-SIT reduces symptom and rescue medication scores, but no changes in BHR to methacholine or sputum eosinophilia were observed. Moreover, Parietaria-SIT appears to prevent the natural progression of allergic rhinitis to asthma, suggesting that SIT should be considered earlier in the management of subjects with allergic rhinitis.

A randomized, controlled study of specific immunotherapy in monosensitized subjects with seasonal rhinitis: effect on bronchial hyperresponsiveness, sputum inflammatory markers and development of asthma symptoms

Allergic rhinitis is often associated with bronchial hyperresponsiveness (BHR) and airway inflammation, and it seems to be an important risk factor for the development of asthma. Specific immunotherapy (SIT) reduces symptoms and medication requirements in subjects with allergic rhinitis, but the mechanisms by which SIT promotes these beneficial effects are less clear. We have investigated the effects of Parietaria-SIT on rhinitis symptoms, BHR to inhaled methacholine, eosinophilic inflammation and cytokine production (interferon gamma and interleukin-4) in the sputum. The effect on asthma progression was also examined. Thirty non-asthmatic subjects with seasonal rhinitis and monosensitized to Parietaria judaica participated in a randomized, double-blind, placebo-controlled, parallel group study. Participants were randomly assigned to receive injections of a Parietaria pollen vaccine (n = 15) or matched placebo injections (n = 15) in a rapid updosing cluster regimen for 7 weeks, followed by monthly injections for 34 months. Throughout the 3-year study we collected data on symptoms and medication score, airway responsiveness to methacholine, eosinophilia and soluble cytokines in sputum, followed by a complete evaluation of the clinical course of atopy. Hay fever symptom and medication scores were well controlled by SIT. By the end of the study, in the placebo group, symptom and medication scores significantly increased by a median (interquartile range) of 121% (15-280%) and 263% (0-4400%) respectively (p < 0.01), whereas no significant difference was observed in the SIT group. We found no significant changes in the sputum parameters and methacholine PC15 values in both groups throughout the study. By the end of the investigation, a total of 9 out of 29 participants developed asthma symptoms; of these, seven (47%) belonged to the placebo group, whereas only 2 (14%) to the SIT-treated group (p = 0.056). In conclusion, Parietaria-SIT is effective in controlling hay fever symptoms and rescue medications, but no changes in the BHR to methacholine or sputum eosinophilia were observed. Moreover, Parietaria-SIT appears to prevent the natural progression of allergic rhinitis to asthma, suggesting that SIT should be considered earlier in the management of this condition.

The lung as a privileged site for the beneficial actions of PGE2

Prostaglandin E2 (PGE2) is commonly considered a potent proinflammatory mediator and is involved in several inflammatory diseases. In the lung, as opposed to many other parts of the body, PGE2 has a role in limiting the immune-inflammatory response as well as tissue repair processes. Understanding the full implications of the regulatory role of PGE2 and how beneficial processes, such as inflammation and tissue repair, become dysregulated to the point of causing disease, might disclose new perspectives in the treatment of pulmonary diseases.

β-Amyloid-Activated Cell Cycle in SH-SY5Y Neuroblastoma Cells: Correlation with the MAP Kinase Pathway

Primary cultures of rat cortical neurons exposed to toxic concentrations of beta-amyloid peptide (betaAP) begin an unscheduled mitotic cell cycle that does not progress beyond the S phase. To analyze possible signal transduction pathways involved in this effect, the action of betaAP has been studied in SH-SY5Y neuroblastoma cells differentiated by a 7-d exposure to 10 microM retinoic acid. Treatment with the betaAP fragment, betaAP(25-35), (25 microM) for 24, 48, or 72 h caused apoptotic cell death, detected by flow cytometry as a prediploid cell population. Cell cycle analysis showed that betaAP(25-35) modified cell cycle profiles by markedly increasing the number of cells in the S phase and reducing the population of the G2/M area. These effects seem to involve activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK1/2). Inhibition of this pathway by the specific inhibitor PD98059 (2 microM) completely prevented changes of cell cycle distribution induced by betaAP and significantly reduced neuronal death. The data suggest that MAPK cascade can mediate the induction of cell cycle induced by betaAP, thus contributing to the toxicity of the peptide.

Impact of intranasal budesonide on immune inflammatory responses and epithelial remodeling in chronic upper airway inflammation

BACKGROUND

Histologic and immunohistologic features of nasal polyps (NP) are similar to those observed in asthma, thus suggesting a similar immunopathology.

OBJECTIVE

The primary objective of this study was to further understand the anti-inflammatory and immunoregulatory effects of locally delivered corticosteroids. To this end, the effect of intranasal budesonide on the expression of specific cytokines, lymphocyte subsets, and epithelial remodeling in this model of airway tissue inflammation were studied.

METHODS

We used immunohistochemical techniques to examine nasal mucosae (NM) from healthy individuals and nasal polyp (NP) tissues from patients with nasal polyposis obtained before and after intranasal budesonide treatment.

RESULTS

First, the density of CD8(+) cells was markedly increased in NP tissues after intranasal budesonide treatment from 16.1 +/- 8.4 (M +/- SEM) per mm(2) to 39.9 +/- 24.1. Second, the density of cells immunoreactive for IL-4, IL-5, IFN-gamma, IL-12, and TGF-beta in NP was significantly greater than in control NM tissues. The density of IL-4(+) and IL-5(+) cells in NP tissues significantly decreased after budesonide treatment from 40 +/- 12 to 17.8 +/- 8 and from 19.3 +/- 11 to 10.4 +/- 7, respectively. In contrast, the density of IFN-gamma(+) and IL-12(+) cells remained unchanged. In addition, we found that the density of TGF-beta(+) cells significantly increased after intranasal budesonide from 18 +/- 5 to 41 +/- 9. Third, damage to the entire length of the NP epithelium was quantified using a grading system. The epithelium of untreated NP was substantially damaged; remarkable epithelial restitution with no apparent changes in stromal collagen deposition was observed after intranasal budesonide treatment.

CONCLUSIONS

These findings demonstrate that intranasal budesonide induced an increase in CD8 population and a selective regulatory effect on tissue cytokine expression. Furthermore, intranasal budesonide promoted epithelial remodeling. We hypothesize that these immunoregulatory and remodeling effects elicited by steroids might be, at least in part, mediated by the induction of TGF-beta.

Inhibitory effect of a leukotriene receptor antagonist (montelukast) on neurokinin A-induced bronchoconstriction

BACKGROUND

Tachykinins are potent contractors of human airways producing a dose-related bronchoconstriction when administered by means of inhalation to asthmatic subjects.

OBJECTIVE

The aim of this study was to examine the effective role played by leukotrienes (LTs) in neurokinin A (NKA)-induced bronchoconstriction in asthmatic patients.

METHODS

To address this question, we investigated the protective effect of a selective cysteinyl LT receptor antagonist, montelukast, against inhaled NKA and determined LTE(4) excretion in the urine.

RESULTS

Inhaled NKA in the absence of any drug treatment produced a concentration-related bronchospasm with a geometric mean provocative concentration required to produce a 15% decrease in FEV(1) from the postsaline baseline value (PC(15)) value of 290.9 microg/mL (+SE, 407.1 microg/mL; -SE, 207.84 microg/mL). Montelukast pretreatment significantly increased (P <.01) the PC(15) NKA value (708.8 microg/mL; +SE, 890.47 microg/mL; -SE, 564.15 microg/mL) in comparison with placebo (394.4 microg/mL; +SE, 491.88 microg/mL; -SE, 248.16 microg/mL) and produced a shift of the NKA concentration-response curve to the right in all the subjects studied. When compared with placebo, montelukast did not have a significant protective effect against methacholine challenge; the geometric mean PC(15) values obtained were 0.87 and 0.96 mg/mL with placebo and montelukast, respectively. Although we have not observed any increase in urinary LTE(4) excretion after NKA inhalation, we have shown that pretreatment of asthmatic subjects with montelukast elicits a significant protection against NKA-induced bronchoconstriction.

CONCLUSION

In asthmatic subjects NKA-induced bronchoconstriction is indirectly caused by the release of LTs, and this mechanism could explain some of the antiasthmatic and anti-inflammatory effects of LT antagonists.

Erratic expression of DNA polymerases by beta-amyloid causes neuronal death

An ectopic reentrance into the cell cycle with ensuing DNA replication is required for neuronal apoptosis induced by beta-amyloid. Here, we investigate the repertoire of DNA polymerases expressed in beta-amyloid-treated neurons, and their specific role in DNA synthesis and apoptosis. We show that exposure of cultured cortical neurons to beta-amyloid induces the expression of DNA polymerase-beta, proliferating cell nuclear antigen, and the p49 and p58 subunits of DNA primase. Induction requires the activity of cyclin-dependent kinases. The knockdown of the p49 primase subunit prevents beta-amyloid-induced neuronal DNA synthesis and apoptosis. Similar effects are observed by knocking down DNA polymerase-beta or by using dideoxycytidine, a preferential inhibitor of this enzyme. Thus, the reparative enzyme DNA polymerase-beta unexpectedly mediates a large component of de novo DNA synthesis and apoptotic death in neurons exposed to beta-amyloid. These data indicate that DNA polymerases become death signals when erratically expressed by differentiated neurons.

Role of oxidative stress in pulmonary fibrosis

Pulmonary fibrosis can be observed as an end state in a number of chronic inflammatory pulmonary diseases. Although the mechanisms by which lung fibrosis develops are not fully ascertained, recent findings suggest that oxidative stress may play an important role in the pathogenesis of tissue fibrosis affecting apoptosis of both structural and inflammatory cells and altering the cytokine microenvironment balance. Damage and alteration of alveolar epithelial cells is one of the hallmarks of interstitial lung fibrosis. Recently, it has been demonstrated that the presence of oxidative stress may lead to the damage, activation and/or apoptosis of alveolar epithelial cells either directly, through an imbalanced intracellular redox equilibrium, or indirectly, by activating redox-sensitive effector pathways, such as transcription factors and angiotensin converting enzyme, increasing the conversion of angiotensinogen into angiotensin II that can be considered a mediator of oxidative stress, capable of inducing apoptosis. Furthermore, it has been demonstrated that angiotensin II acts as a proinflammatory cytokine and is effective in activating fibroblasts through the release of transforming growth factor (TGF-beta). As well as activation, differentiation, proliferation and apoptosis of fibroblasts seem related to the oxidant/antioxidant balance, and the maintenance of a high intracellular level of reduced glutathione (GSH) is considered crucial in providing a reducing environment within the cell, able to protect against oxidative stress. In those conditions where oxidants, either inhaled or produced by inflammatory cell, increase, the ratio between GSH and oxidized glutathione (GSSH) may lower, influencing a variety of cellular redox-sensitive signaling processes such as the activation of nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) that lead to a transcriptional up-regulation of a number of genes involved in inflammation and/or fibrogenesis, including cytokines [interleukin (IL)-1,, tumor necrosis factor (TNF-alpha), IL-6] chemokines (IL-8), adhesion molecules (VCAM-1, ICAM-1) and growth factors (GM-CSF). In addition, several studies have shown that oxidative stress may also affect the immune response by inducing an up-regulation of HLA-DR as well as the expression of two costimulatory molecules such as CD40 and CD86, determining a persistent state of immune activation, and affecting the Th1/Th2 balance, modulating the T-cell effector response towards the Th2 phenotype. It is clear that a better understanding of the precise sequence of events that make the difference between normal tissue repair and fibrosis, including the role played by oxidative stress, will certainly improve our therapeutic approach to pulmonary fibrosis.

Normal human lung fibroblasts differently modulate interleukin-10 and interleukin-12 production by monocytes: implications for an altered immune response in pulmonary chronic inflammation

The ability of lung fibroblasts to modulate the immune response has been evaluated by analyzing the synthesis and release of interleukin (IL)-10 and IL-12 by lipopolysaccharide (LPS)-stimulated peripheral blood monocytes exposed to pulmonary fibroblast conditioned medium (FCM). IL-10 and IL-12 contents and gene expression were markedly modified by treatment with FCM as measured by ELISA (+97.5 +/- 12.8% and -68 +/- 7.3% for IL-10 and IL-12, respectively), immunocytochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR). These effects appeared to be mediated by prostaglandin E(2) (PGE(2)) as the modified release of both cytokines was reduced by treatment with indomethacin and mimicked by addition of exogenous PGE(2.) As a result of the enhanced production of IL-10, exposure of LPS/interferon (IFN)-gamma-activated monocytes to FCM was also able to reduce the expression of the class II major histocompatibility complex (MHC) molecule, human leukocyte-associated antigen-DR (HLA-DR) (-51.8 +/- 8.7%) and of the costimulatory molecule, CD40 (-53.9 +/- 11.7%). The expression of both molecules was completely restored when monocytes were pretreated with a neutralizing anti-IL-10 monoclonal antibody. The FCM obtained from fibrotic lung fibroblasts was instead less efficacious in potentiating LPS-stimulated IL-10 release and, consequently, in reducing HLA-DR and CD40 expression, suggesting that an impairment of the immune regulation operated by fibroblasts may be involved in the maintenance of chronic pulmonary inflammation.

Intranasal heparin reduces eosinophil recruitment after nasal allergen challenge in patients with allergic rhinitis

BACKGROUND

Recently, several studies have shown that heparin possesses various anti-inflammatory and antiallergic properties. It has been proposed that heparin might play an important role in limiting the inflammatory events associated with asthma and allergic rhinitis by neutralizing inflammatory mediators, such as eosinophil cationic protein and major basic protein, and by limiting eosinophil recruitment.

OBJECTIVE

To test the hypothesis that heparin can limit the extent and magnitude of eosinophilic inflammation, we examined the effect of inhaled intranasal heparin on nasal response to allergen challenge in 10 patients with allergic rhinitis.

METHODS

The capacity of heparin to reduce nasal response was studied by evaluating symptom score, eosinophil cationic protein concentration, and eosinophil counts in nasal lavage fluids 10, 60, and 360 minutes after allergen challenge.

RESULTS

Pretreatment with intranasal heparin produced a significant reduction in symptom score 10 minutes after allergen challenge and reduced the eosinophil influx at each time point after antigen challenge, statistical significance being reached 60 and 360 minutes after allergen challenge. Similarly, the amount of eosinophil cationic protein in the nasal wash was reduced at each time point; this reached statistical significance 360 minutes after allergic challenge.

CONCLUSION

Heparin was shown to provide protection with respect to nasal allergen challenge. The mechanism by which heparin produces its protective activity seems to be related to the neutralization of eosinophil cationic protein as well as to the reduction of eosinophil recruitment.

Different expression of TNF-alpha receptors and prostaglandin E(2 )Production in normal and fibrotic lung fibroblasts: potential implications for the evolution of the inflammatory process

Normal human lung fibroblasts downregulate the production of tumor necrosis factor (TNF)-alpha by activated monocytes through the production of prostaglandin E(2) (PGE(2)), contributing to the local control of the inflammatory process. In this study, we provide evidence that fibroblasts derived from diseased tissue, such as fibrotic lung fibroblasts, exhibit different functional features compared with normal cells, with particular regard to their modulatory role. Indeed, fibrotic fibroblasts (FF) spontaneously produced less PGE(2) (3,300 +/- 410 pg/ml) compared with normal fibroblasts (NF) (7,500 +/- 270 pg/ml) and, as a consequence, they showed a reduced ability to downregulate the production of TNF-alpha by lipopolysaccharide (LPS)- activated monocytes. The percentage of inhibition induced by normal cells on the production of TNF-alpha by LPS-activated monocytes was 61 +/- 5.9%, whereas the inhibitory effect exerted by fibrotic cells was reduced to 32 +/- 4% (P < 0.01). We have also observed that the ability of TNF-alpha to induce PGE(2) was impaired in FF and was related to a reduced expression of cyclooxygenase 2. This was possibly due to the reduction of the expression of TNF receptors (TNFRs) in fibrotic cell lines compared with normal cell lines. Flow cytometry revealed that the mean fluorescence intensity (MFI) of both isoforms of TNFR was significantly lower in FF compared with NF. The MFI of TNFR1 was 3. 55 +/- 0.12 for NF and 1.78 +/- 0.35 for FF (P < 0.001). The MFI of TNFR2 was 1.95 +/- 0.27 for NF and 0.99 +/- 0.16 for FF (P < 0.01). The analysis of the effect of TNF-alpha on some functions associated with collagen metabolism in NF and FF showed an increase of the expression of the receptor for collagen type I (alpha(2)beta(1) integrin) in NF (42 +/- 10%) and an even larger increase in FF (102 +/- 23%) (P < 0.05). Interestingly, unlike NF, TNF-alpha failed to increase matrix metalloproteinase 1 levels in FF and did not cause any growth inhibition in these cells. The reduced capability of fibrotic cells to produce PGE(2) either spontaneously or after TNF-alpha treatment may lead to an unrestrained release of TNF-alpha from activated monocytes and, as a result of the reduced expression of TNFRs, to a different response of these cells to TNF-alpha. These changes may be important in the evolution of the inflammatory process, potentially contributing to its transformation into a chronic and self-perpetuating process.

Bronchial hyperresponsiveness and airway inflammation markers in nonasthmatics with allergic rhinitis

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma which is often associated with airways inflammation. However, some patients with allergic rhinitis and no clinical evidence of asthma also exhibit BHR. This study therefore investigated whether inflammatory cell infiltrate is present in the induced sputum of nonasthmatic subjects with allergic rhinitis during the pollen season and examined its relationship with airway hyperresponsiveness to inhaled methacholine and adenosine 5'-monophosphate (AMP). Twenty subjects (12 allergic rhinitis, eight nonallergic controls) underwent methacholine and AMP challenge and sputum induction with hypertonic saline on separate days. Cell differentials were calculated from whole sputum samples. A significantly greater number of eosinophils was found in the sputum of nonasthmatic subjects with allergic rhinitis compared to that of nonallergic controls, their median (range) percentages being 17.5 (4-47) and 1.5 (0-5) (p<0.001) respectively. Although sputum eosinophilia failed to be significantly associated with methacholine responsiveness (r(s)=-0.50; p=0.095), the provocative concentration of AMP causing a 20% fall in forced expiratory volume in one second correlated strongly and significantly with the absolute number of eosinophils (r(s)= -0.73; p=0.007). Eosinophil cationic protein levels in the sputum of rhinitic subjects were significantly elevated compared to controls and correlated with eosinophil number (r(s)=0.67; p=0.017). These findings support the view that bronchial eosinophilia alone is insufficient to cause asthmatic symptoms. Diverse agonists for assessing bronchial hyperresponsiveness are selectively associated with airway inflammation in allergic rhinitis.

Mitogenic effect of nerve growth factor (NGF) in LNCaP prostate adenocarcinoma cells: role of the high- and low-affinity NGF receptors

We have investigated the effect of nerve growth factor (NGF) in the androgen-dependent, prostate adenocarcinoma LNCaP cell line. Exposure of LNCaP cells to NGF resulted in a significant increase of cell proliferation. The effect was concentration dependent and equally present in serum- or charcoal-stripped serum-supplemented and serum-deprived conditions. The mitogenic action of NGF was accompanied by an enhanced expression of prostate-specific antigen (PSA) and resulted additive to the proliferative effect of dihydrotestosterone. The proliferative effect of NGF appeared to be mediated by the high-affinity NGF receptor, p140trka. Only p140trka, but not the low-affinity NGF receptor, p75LNGFR, was expressed in LNCaP cells; both the proliferative response and the phosphorylation of p140trka upon NGF treatment were prevented by the tyrosine kinase inhibitor K252a. LNCaP cells transiently transfected with the cDNA encoding for p75LNGFR appeared more sensitive to NGF, as demonstrated by the increased number of p75LNGFR-transfected LNCaP cells exposed for 72 h to NGF compared with wild LNCaP cultures. However, p75LNGFR-transfected LNCaP cells rapidly underwent apoptotic death when deprived of NGF. Our study demonstrates the physiological relevance of NGF in the regulation of prostate cell proliferation and the relative contribution of the high- and low-affinity NGF receptors in this control.