25-hydroxycholesterol promotes fibroblast-mediated tissue remodeling through NF-κB dependent pathway

Abnormal structural alterations termed remodeling, including fibrosis and alveolar wall destruction, are important features of the pathophysiology of chronic airway diseases such as chronic obstructive pulmonary disease (COPD) and asthma. 25-hydroxycholesterol (25-HC) is enzymatically produced by cholesterol 25-hydorxylase (CH25H) in macrophages and is reported to be involved in the formation of arteriosclerosis. We previously demonstrated that the expression of CH25H and production of 25HC were increased in the lungs of COPD. However, the role of 25-HC in lung tissue remodeling is unknown. In this study, we investigated the effect of 25-HC on fibroblast-mediated tissue remodeling using human fetal lung fibroblasts (HFL-1) in vitro. 25-HC significantly augmented α-smooth muscle actin (SMA) (P<0.001) and collagen I (P<0.001) expression in HFL-1. 25-HC also significantly enhanced the release and activation of matrix metallaoproteinase (MMP)-2 (P<0.001) and MMP-9 (P<0.001) without any significant effect on the production of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. 25-HC stimulated transforming growth factor (TGF)-β1 production (P<0.01) and a neutralizing anti-TGF-β antibody restored these 25-HC-augmented pro-fibrotic responses. 25-HC significantly promoted the translocation of nuclear factor (NF)-κB p65 into the nuclei (P<0.01), but not phospholylated-c-jun, a complex of activator protein-1. Pharmacological inhibition of NF-κB restored the 25-HC-augmented pro-fibrotic responses and TGF-β1 release. These results suggest that 25-HC could contribute to fibroblast-mediated lung tissue remodeling by promoting myofibroblast differentiation and the excessive release of extracellular matrix protein and MMPs via an NF-κB-TGF-β dependent pathway.

Cigarette smoke augments the expression and responses of toll-like receptor 3 in human macrophages

BACKGROUND AND OBJECTIVE

Cigarette smoking is the main risk factor for the development of chronic obstructive pulmonary disease (COPD). Recently, toll-like receptor 3 (TLR3) was shown to recognize pathogen-associated molecular patterns, especially viral-derived double-stranded RNA, and to be involved in immune responses. However, the effects of cigarette smoke on TLR3 remain unclear. In this study, it was examined whether cigarette smoke affects the expression and responses of TLR3 in human macrophages.

METHODS

The expression of TLR3 in alveolar macrophages from human lung tissues was analysed by immunohistochemistry, and the correlation of TLR3 expression with smoking history and lung function was evaluated. In addition, the effect of cigarette smoke on the expression and responses of TLR3 in macrophage lineage cells was investigated.

RESULTS

TLR3-positive alveolar macrophage numbers were significantly increased in smokers and COPD patients compared with non-smoking control subjects, but there was no difference between smokers and COPD patients. TLR3-positive macrophage numbers were positively correlated with smoking history and inversely correlated with corrected carbon monoxide diffusing capacity, but were not correlated with % predicted forced expiratory volume in 1 s. Furthermore, cigarette smoke extract potentiated the expression of TLR3 in monocyte-derived macrophages and significantly augmented the release of interleukin-8, as well as total matrix metalloproteinase-9 activity, in cells treated with TLR3 ligand.

CONCLUSIONS

These data suggest that cigarette smoke augments the expression and responses of TLR3 in human macrophages, and this may contribute to neutrophilic airway inflammation and parenchymal destruction in the lungs of smokers and patients with COPD.

A rare association between Rathke's cyst and hypophysitis in a patient with delayed sex development and growth failure

We report an 18-year-old Japanese male with a lack of secondary sex characterization and growth failure caused by a rare association between Rathke's cyst and hypophysitis. He was referred to us because of delayed secondary sex characterization. Endocrinological examination showed panhypopituitarism, and the replacement of hydrocortisone, levothyroxine, and desmopressin acetate (DDAVP) was initiated. Brain magnetic resonance imaging (MRI) showed a suprasellar region and a swollen pituitary stalk. The mass was partially resected using the transsphenoidal approach. The pathological diagnosis was hypophysitis and Rathke's cyst. Follow-up MRI performed 1 year after surgery showed that the size of sellar region had not changed. After surgery, in addition to pre-operative hormonal replacement, growth hormone and testosterone were initiated. Two years later, the size of sellar region remains unchanged. In conclusion, while an association between Rathke's cyst and hypophysitis is rare, we suggest that this condition should be included in differential diagnosis of the sellar region, even in adolescents.

Differential roles of JNK, ERK1/2, and p38 mitogen-activated protein kinases on endothelial cell tissue repair functions in response to tumor necrosis factor-α

Tumor necrosis factor (TNF)-α can alter tissue repair functions in a variety of cells including endothelial cells. However, the mechanism by which TNF-α mediates these functional changes has not fully been studied. We investigated the role of mitogen-activated protein kinases (MAPKs) on mediating the regulatory effect of TNF-α on the tissue repair functions of human pulmonary artery endothelial cells (HPAECs). TNF-α protected HPAECs from undergoing apoptosis induced by serum and growth factor deprivation, augmented collagen gel contraction, and stimulated wound closure. TNF-α activated c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and p38. Inhibitors of JNK (SP600125, 5 µM) or ERK1/2 (PD98059, 5 µM) significantly inhibited TNF-α-stimulated cell survival, contraction of collagen gels, and wound closure. In contrast, the p38 inhibitor SB203580 (5 µM) further amplified all of the TNF-α effects on HPAECs. TNF-α specifically activated p38α but not other p38 isoforms and suppression of p38α by an siRNA resulted in further amplification of the TNF-α effect. These results suggest that TNF-α stimulates tissue repair functions of HPAECs, and this may be mediated, at least in part, positively via JNK and ERK1/2, and negatively through p38α. MAPKs may play a role in endothelial cell-mediated tissue repair, especially in an inflammatory milieu where TNF-α is present.

Increase of 27-hydroxycholesterol in the airways of patients with COPD: possible role of 27-hydroxycholesterol in tissue fibrosis

BACKGROUND

27-Hydroxycholesterol (27-OHC) is produced from cholesterol by sterol 27-hydroxylase as an intermediate in the biosynthesis pathway of bile acid. Recently, 27-OHC was reported to cause inflammation and apoptosis in various types of cells. The aim of this study was to assess the production of 27-OHC in the airways of patients with COPD and to elucidate the possible role of 27-OHC in the tissue fibrosis of COPD.

METHODS

Lung tissues were obtained from six control subjects and six patients with COPD, and sputum samples were obtained from 11 healthy subjects and 15 patients with COPD. The expression of sterol 27-hydroxylase in the lung was investigated by immunohistochemistry. The amounts of 27-OHC in the sputum were quantified by the liquid chromatography-tandem mass spectrometry method. Because peribronchial fibrosis in peripheral airways is involved in the airflow limitation of COPD, we investigated the profibrotic effects of 27-OHC in vitro.

RESULTS

The expression of sterol 27-hydroxylase was significantly enhanced in the lung tissues of patients with COPD compared with control subjects. The amounts of 27-OHC in the sputum were significantly increased in the patients with COPD (P < .01), and the degree of 27-OHC production was negatively correlated with lung function (P < .01). 27-OHC augmented the differentiation of lung fibroblasts into myofibroblasts and the production of extracellular matrix protein through activation of nuclear factor-κB and subsequent transforming growth factor-β(1) upregulation.

CONCLUSIONS

27-OHC production is enhanced in the airways of patients with COPD and might be involved in the pathogenesis of COPD.

Analysis of structural and electronic properties of Pr2NiO4 through first-principles calculations

The structural and electronic properties of bulk Pr(2)NiO(4+δ) (δ = 0 and 0.031) were analyzed using first-principles calculations based on the density functional theory (DFT) for application to electrode materials in solid-oxide fuel cells (SOFCs). Two structures of Pr(2)NiO(4) were analyzed: one in space group I4/mmm associated with the high temperature tetragonal (HTT) structure, and the other in Bmab with the low temperature orthorhombic (LTO) structure. The main difference between the two structures is the pronounced tilting of the nickelate octahedra found in the Bmab structure. Here, we will show that the difference in the electronic properties between the two structures, i.e. half-metallic for the I4/mmm structure and metallic for the Bmab structure, is attributed to the tilting of the nickelate octahedra. Furthermore, we found that the presence of interstitial O atoms at the Pr(2)O(2) bilayers is responsible for the tilting of the octahedra and thus is a dominant factor in the transition from the I4/mmm structure to the Bmab structure. These results would be of great significance to materials design related to the enhancement of O diffusivity in this material.

Attenuation of inhibitory prostaglandin E2 signaling in human lung fibroblasts is mediated by phosphodiesterase 4

The etiology of chronic obstructive pulmonary disease (COPD) is complex and involves an aberrant inflammatory response. Prostaglandin (PG)E2 is elevated in COPD, is a key modulator of lung fibroblast functions, and may influence COPD progression. Most studies evaluating the effects of PGE2 on lung fibroblasts have used acute exposures. The current study evaluated whether longer-term exposure would induce attenuation of PGE2 signaling as part of an autoregulatory pathway. Human fetal lung fibroblasts were pretreated with PGE2 for 24 hours, and migration and cAMP accumulation in response to acute stimulation with PGE2 were assessed. Fibroblasts from adults with and without COPD were pretreated, and migration was assessed. PGE2 pretreatment attenuated subsequent PGE2-mediated inhibition of chemotaxis and cAMP stimulation. This attenuation was predominantly due to an increase in phosphodiesterase (PDE)4-mediated degradation of cAMP rather than to decreased activation of PGE2 receptors (receptor desensitization). Albuterol- and iloprost-mediated signaling were also attenuated after PGE2 pretreatment, suggesting that activation of PDE4 was able to broadly modulate multiple cAMP-coupled pathways. Lung fibroblasts from adult control subjects pretreated with PGE2 also developed attenuation of PGE2-mediated inhibition of chemotaxis. In contrast, fibroblasts obtained from patients with COPD maintained inhibitory PGE2 signaling after PGE2 pretreatment. These data identify a PDE4-mediated attenuation of PGE2 inhibitory signaling in normal fibroblasts that appears to be altered in COPD fibroblasts. These alterations may contribute to COPD pathogenesis and could provide novel therapeutic targets.

Childhood-onset anti-MuSK antibody positive myasthenia gravis demonstrates a distinct clinical course

Anti-muscle-specific tyrosine kinase antibody (MuSK-Ab) is the second most frequent autoantibody identified in adult patients with myasthenia gravis (MG). Adult patients with MuSK-Ab demonstrate characteristic clinical features but very little information is available for childhood-onset patients with MuSK-positive MG. We report a childhood-onset female patient with MuSK-positive MG. This patient showed basic clinical features compatible with adult-onset MuSK-positive MG, but some features, including spontaneous improvement, are distinct from those in adult patients. Serial examination of MuSK-Ab titers revealed a gross correlation with clinical severity despite significantly high titers throughout the clinical course. Therefore, childhood-onset MuSK-positive MG may demonstrate a distinct clinical characteristics in the early period of illness.

Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study

PURPOSE

To assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome.

METHODS

This study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events.

RESULTS

We found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes.

CONCLUSIONS

In dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

Clinical evaluation of the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome: a prospective, randomized, multicenter study

PURPOSE

To assess the additive effect of diquafosol tetrasodium on sodium hyaluronate monotherapy in patients with dry eye syndrome.

METHODS

This study evaluated 64 eyes of 32 patients (age: 62.6±12.8 years (mean±SD)) in whom treatment with 0.1% sodium hyaluronate was insufficiently responsive. The eyes were randomly assigned to one of the two regimens in each patient: topical administration of sodium hyaluronate and diquafosol tetrasodium in one eye, and that of sodium hyaluronate in the other. Before treatment, and 2 and 4 weeks after treatment, we determined tear volume, tear film break-up time (BUT), fluorescein and rose bengal vital staining scores, subjective symptoms, and adverse events.

RESULTS

We found a significant improvement in BUT (P=0.049, Dunnett test), fluorescein and rose bengal staining scores (P=0.02), and in subjective symptoms (P=0.004 for dry eye sensation, P=0.02 for pain, and P=0.02 for foreign body sensation) 4 weeks after treatment in the diquafosol eyes. On the other hand, we found no significant change in these parameters after treatment in the control eyes.

CONCLUSIONS

In dry eyes, where sodium hyaluronate monotherapy was insufficient, diquafosol tetrasodium was effective in improving objective and subjective symptoms, suggesting its viability as an option for the additive treatment of such eyes.

25-Hydroxycholesterol enhances cytokine release and Toll-like receptor 3 response in airway epithelial cells

Background

25-hydroxycholesterol (25-HC) is one of the oxysterols, which are oxidized derivatives of cholesterol, and has been reported to be involved in the pathogenesis of atherosclerosis and Alzheimer’s disease. In lung, the possible involvement of 25-HC in airway diseases has been revealed. In the present study, we examined whether 25-HC affects the release of cytokines and also modulates the responses of toll-like receptor 3 (TLR3) in airway epithelial cells.

Methods

The effect of 25-HC on the release of cytokines from primary human bronchial epithelial cells after stimulation with or without polyinosine-polycytidylic acid [poly(I:C)], a ligand for TLR3, and the signal transduction were examined.

Results

25-HC significantly potentiated the release of interleukin-8 (IL-8) and IL-6 from the cells. This effect was more potent compared with that of other oxysterols, 22-HC and 27-HC. GW3965 and TO901317, synthetic agonists of liver X receptors that are receptors for oxysterols, did not augment the IL-8 release. 25-HC enhanced the nuclear factor-kappa B (NF-κB) DNA binding activity and translocation of phosphorylated c-Jun into the nucleus. The release of IL-8 was inhibited by the NF-κB inhibitor, caffeic acid phenethyl ester (CAPE), an inhibitor of nuclear factor kappa-B alpha (IκBα) inhibitor, BAY 11–7085, and an inhibitor of nuclear factor kappa-B kinase-2 (IKK-2) inhibitor, SC-514, but not by a c-Jun N-terminal kinase (JNK) inhibitory peptide, L-JNKi1. 25-HC significantly potentiated IL-8 release in poly(I:C)-treated cells and the augmentation was inhibited by CAPE, BAY 11–7085, and SC-514. Furthermore, 25-HC potentiated the translocation of interferon regulatory factor 3 into the nucleus and the release of interferon-beta (IFN-β) in poly(I:C)-treated cells.

Conclusions

These data demonstrated that 25-HC augments the release of IL-8 and IL-6 via NF-κB signalling pathway and enhances the release of IL-8 and IFN-β after stimulation of TLR3 in airway epithelial cells. 25-HC may be involved in the neutrophilic airway inflammation through the stimulant effect of IL-8 and IL-6 release and also potentiate the TLR3-mediated innate immunity in airway diseases.

Community-acquired pneumonia distinguished from influenza infection based on clinical signs and symptoms during a novel (swine) influenza A/H1N1 pandemic

AIMS

The numbers of patients with influenza-like illnesses increase during influenza outbreaks. A study was undertaken to distinguish community-acquired pneumonia (CAP) from influenza based on clinical signs and symptoms.

METHODS

This retrospective study investigated patients with positive results in the rapid influenza antigen test and those diagnosed with CAP during an influenza A/H1N1 pandemic. Significant factors for predicting risk for CAP within 48 hrs from onset and at diagnosis were selected by multiple regression analysis.

RESULTS

Within 48 hrs of onset and at diagnosis, age and coarse crackles significantly increased the risk of CAP whereas sick contact, sore throat, and rhinorrhoea significantly decreased the risk of CAP. Duration of illness, sputum, dyspnoea, chest pain, and coarse crackles also significantly increased the risk of CAP at diagnosis.

CONCLUSIONS

CAP differed somewhat from influenza even within 48 hrs of onset and the differences became even more evident thereafter.

Inhibitory effects of theophylline on the peroxynitrite-augmented release of matrix metalloproteinases by lung fibroblasts

The anti-inflammatory effects of theophylline have been reported to include inhibition of the release of proinflammatory mediators from macrophages and neutrophils. Overproduction of reactive nitrogen species (RNS) has been reported in the airways of patients with chronic obstructive pulmonary disease (COPD), and this causes tissue inflammation and injury. We investigated whether peroxynitrite stimulated the release of matrix metalloproteinases 2 and 9 (MMP-2 and -9; gelatinases) from human fetal lung fibroblasts (HFL-1 cell line) and whether theophylline inhibited the peroxynitrite-augmented release of MMPs. HFL-1 cells and primary lung fibroblasts were treated with peroxynitrite (an RNS), and gelatinases levels were evaluated by gelatin zymography. The inhibitory effect of theophylline on the peroxynitrite-augmented release of MMP-2 and MMP-9 was also investigated. To explore the cell signaling pathways involved in the peroxynitrite-induced gelatinases release and the inhibitory effect of theophylline, transforming growth factor-β1 (TGF-β1), nuclear factor-κB (NF-κB), and histone deacetylase (HDAC) were measured. Peroxynitrite significantly augmented the release of MMP-2 and MMP-9 by fibroblasts ( P < 0.01), as well as TGF-β1 release ( P < 0.01), NF-κB activation ( P < 0.01), and HDAC2 inactivation ( P < 0.01). An NF-κB inhibitor diminished the RNS-augmented release of MMPs and TGF-β1 ( P < 0.01), and a neutralizing TGF-β antibody also diminished MMP release ( P < 0.01). Theophylline significantly inhibited the peroxynitrite-augmented release of MMP-2 and MMP-9 in HFL-1 cells and normal adult lung fibroblasts, and it also inhibited the peroxynitrite-mediated HDAC2 inactivation, NF-κB activation, and TGF-β1 release in HFL-1 cells (all P < 0.01). These results suggest that peroxynitrite can influence tissue remodeling by promoting gelatinases release, while theophylline suppresses peroxynitrite-induced tissue remodeling via pathways involving NF-κB/TGF-β1 and/or HDAC in the HFL-1 cell line.

Prostaglandin E2 stimulates the production of vascular endothelial growth factor through the E-prostanoid-2 receptor in cultured human lung fibroblasts

Fibroblasts are the major mesenchymal cells present within the interstitium of the lung and are a major source of vascular endothelial growth factor (VEGF), which modulates the maintenance of pulmonary microvasculature. Prostaglandin E(2) (PGE(2)) acts on a set of E-prostanoid (EP) receptors that activate multiple signal transduction pathways leading to downstream responses. We investigated the modulation by PGE(2) of VEGF release by human lung fibroblasts. Human lung fibroblasts were cultured until reaching 90% confluence in tissue culture plates, after which the culture media were changed to serum-free Dulbecco's modified Eagle's medium, with or without PGE(2), and with specific agonists or antagonists for each EP receptor. After 2 days, culture media were assayed for VEGF by ELISA. The results demonstrated that PGE(2) and the EP2 agonist ONO-AE1-259-01 significantly stimulated the release of VEGF in a concentration-dependent manner. Agonists for other EP receptors did not stimulate the release of VEGF. The stimulatory effect of PGE(2) was blocked by the EP2 antagonist AH6809, but was not blocked by antagonists for other EP receptors. The protein kinase-A (PKA) inhibitor KT-5720 also blocked the stimulatory effect of PGE(2). The increased release of VEGF induced by PGE(2) was accompanied by a transient increase in the concentration of VEGF mRNA. These findings demonstrate that PGE(2) can modulate the release of VEGF by human lung fibroblasts through its actions in the EP2 receptor/PKA pathway. This activity may contribute to the maintenance of pulmonary microvasculature in the alveolar wall.

Inflammatory cytokines regulate endothelial cell survival and tissue repair functions via NF-κB signaling

Inflammation contributes to the development of fibrotic and malignant diseases. We assessed the ability of inflammatory cytokines to modulate endothelial cell survival and functions related to tissue repair/remodeling. Treatment with interleukin (IL)-1β or tumor necrosis factor (TNF)-α (2 ng/mL) led to human pulmonary artery endothelial cells becoming spindle-shaped fibroblast-like cells. However, immunoblot and DNA microarray showed no change in most endothelial and mesenchymal markers. In the presence of IL-1β or TNF-α, cells were resistant to apoptosis induced by deprivation of serum and growth factor, and were more migratory. In addition, cells treated with IL-1β or TNF-α contracted collagen gels more robustly. In contrast, transforming growth factor-β1 did not induce these responses. RNA interference targeting nuclear factor (NF)-κB p65 blocked the effects of IL-1β or TNF-α on cell morphologic change, survival, migration, and collagen gel contraction. These results suggest that endothelial cells may contribute to tissue repair/remodeling via the NF-κB signaling in a milieu of airway inflammation.

Porcine circovirus type 2 potentiates morbidity of Salmonella enterica serovar Choleraesuis in Cesarean-derived, colostrum-deprived pigs

PROBLEM ADDRESSED

Porcine circovirus type 2 (PCV2) and Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) are two leading causes of economic loss in the swine industry. Although S. Choleraesuis infection occurs concurrently with PCV2-associated disease in many swine herds, the pathogenesis of concurrent infection with PCV2 and S. Choleraesuis remains largely undefined.

OBJECTIVE

We investigated the interactions between PCV2 and S. Choleraesuis in 20 Cesarean-derived, colostrum-deprived (CDCD) pigs randomly assigned to 4 groups (n=5 per group).

METHODS AND APPROACH

Pigs in the dual-infected and PCV2-infected groups were inoculated intranasally with PCV2 at 5 weeks of age, and pigs in the dual-infected and S. Choleraesuis-infected groups were inoculated intranasally with S. Choleraesuis at 7 weeks of age. Pigs in the control group served as uninfected controls.

RESULTS

After S. Choleraesuis inoculation, severe clinical signs, reduction of weight gain, and severe microscopic lung lesions were observed in dual-infected pigs compared to those in other groups. In addition, the pigs in the dual-infected group shed significantly (P=0.002) higher quantities of S. Choleraesuis in feces 12 days after S. Choleraesuis inoculation, and S. Choleraesuis was recovered from more tissues in this group 14 days after S. Choleraesuis inoculation.

CONCLUSIONS

These results indicate that prior PCV2 infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of S. Choleraesuis in infected pigs. Therefore, dual infection of pigs with PCV2 and S. Choleraesuis may increase clinical effects of salmonellosis in the field.

Three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies

The clinical phenotype of congenital pituitary hormone deficiency is variable and can be associated with a number of structural abnormalities of the central nervous system. We report three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies. Two of the patients initially showed strabismus and unilateral optic nerve hypoplasia. Thereafter, growth failure became evident, leading to the diagnosis of pituitary hormone deficiency. The other patient had severe congenital hypopituitarism with respiratory distress and hypoglycemia from the first day of life. In addition, he had prolonged jaundice and impaired liver function with bilateral optic nerve hypoplasia. Neuroimaging of the pituitary region in all three patients demonstrated a small anterior pituitary lobe and no pituitary stalk. Our findings indicate that clinical variability of congenital hypopituitarism must be considered. In a patient with ophthalmological symptoms, endocrine evaluation and neuroimaging of the CNS including the pituitary region should be considered.

Significance of the progression of respiratory symptoms for predicting community-acquired pneumonia in general practice

BACKGROUND AND OBJECTIVE

Early diagnosis improves outcomes in patients with community-acquired pneumonia (CAP). However, prediction of CAP based on symptoms and signs is difficult. The present study investigated the evaluation of progression of symptoms as a factor for predicting the occurrence of CAP in general practice.

METHODS

Consecutive patients (n = 406) suspected of having CAP on routine clinical examination were studied retrospectively. Selection of patients with suspected CAP was based on progression of symptoms after 5 days, as well as published criteria. Diagnostic yields for the recommended criteria and our proposed criteria were then compared. Scoring systems for the prediction of CAP were designed, based on the results of multiple regression analysis. The diagnostic performance of these systems, including or excluding symptom progression, was compared using the areas under receiver operating characteristic curves.

RESULTS

The sensitivity and specificity of the recommended criteria and our proposed criteria were 0.75 and 0.44, and 0.93 and 0.38, respectively. Sputum production, dyspnoea, fever > 38 degrees C, heart rate > 100 beats/min, decreased breath sounds, coarse crackles and progression of symptoms significantly increased the likelihood of CAP. Areas under receiver operating characteristic curves analysis showed that the diagnostic prediction of CAP was significantly improved when the scoring system included progression of symptoms.

CONCLUSIONS

Progression of symptoms was a significant factor for predicting CAP and selecting patients who required CXR. Inclusion of progression of symptoms among the other recommended criteria, namely, dyspnoea, fever > 38 degrees C, heart rate > 100 beats/min and abnormal chest findings, improved prediction of the incidence of CAP in general practice.

Reduced miR-146a increases prostaglandin E₂in chronic obstructive pulmonary disease fibroblasts

RATIONALE

Persistent inflammation plays a major role in chronic obstructive pulmonary disease (COPD) pathogenesis, but its mechanisms are incompletely defined. Overproduction of the inflammatory mediator prostaglandin (PG) E₂ by COPD fibroblasts contributes to reduced repair function.

OBJECTIVES

The present study determined if fibroblasts from subjects with COPD overproduce PGE₂ after stimulation with the inflammatory cytokines IL-1β and tumor necrosis factor-α, and further defined the mechanism for overproduction.

METHODS

Fibroblasts were isolated from parenchymal tissue obtained from smokers with and without COPD undergoing lung surgery. PGE₂, cyclooxygenases (COX), and miR-146a in these cells were evaluated by in vitro studies.

MEASUREMENTS AND MAIN RESULTS

After stimulation with inflammatory cytokines, COPD fibroblasts produced 2.7-fold more PGE₂ compared with controls with similar smoking history. The increase in PGE₂ depended on induction of COX-2, which increased to a greater degree in fibroblasts from subjects with COPD. Cytokines also induced microRNA miR-146a expression in both fibroblasts, but significantly less in COPD fibroblasts. miR-146a caused degradation of COX-2 mRNA; reduced expression prolonged COX-2 mRNA half-life in fibroblasts from subjects with COPD. Cytokine-stimulated PGE₂ production and miR-146a expression in cultured fibroblasts correlated with clinical severity assessed by expiratory airflow and diffusion capacity.

CONCLUSIONS

miR-146a seems to play a pathogenetic role in the abnormal inflammatory response in COPD. Increased half-life of inflammatory mRNAs is a mechanism of abnormal inflammation in this disease.

Prostaglandin E₂ inhibits human lung fibroblast chemotaxis through disparate actions on different E-prostanoid receptors

The migration of fibroblasts is believed to play a key role in both normal wound repair and abnormal tissue remodeling. Prostaglandin E (PGE)(2), a mediator that can inhibit many fibroblast functions including chemotaxis, was reported to be mediated by the E-prostanoid (EP) receptor EP2. PGE(2), however, can act on four receptors. This study was designed to determine if EP receptors, in addition to EP2, can modulate fibroblast chemotaxis. Using human fetal lung fibroblasts, the expression of all four EP receptors was demonstrated by Western blotting. EP2-selective and EP4-selective agonists inhibited both chemotaxis toward fibronectin in the blindwell assay and migration in a wound-closure assay. In contrast, EP1-selective and EP3-selective agonists stimulated cell migration in both assay systems. These results were confirmed using EP-selective antagonists. The role of both EP2 and EP4 receptors in mediating the PGE(2) inhibition of chemotaxis was also confirmed by small interfering RNA suppression. Furthermore, the role of EP receptors was confirmed by blocking the expected signaling pathways. Taken together, these results demonstrate that PGE(2) can act on multiple EP receptors in human lung fibroblasts, to exert disparate effects. Alterations in EP receptor expression may have the potential to alter PGE(2) action. Targeting specific EP receptors may offer therapeutic opportunities in conditions characterized by abnormal tissue repair and remodeling.