Expression of monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 by human airway smooth-muscle cells. Modulation by corticosteroids and T-helper 2 cytokines

Evaluation of serum MIP-1β and MCP-2 levels in major depressive disorder: A case-control study

BACKGROUND

Major depressive disorder (MDD) is a common and debilitating mental illness characterized by persistent feelings of sadness, hopelessness, and a lack of interest in daily activities. The objective of this study was to investigate whether levels of macrophage inflammatory protein-1β (MIP-1β) and macrophage chemoattractant protein-2 (MCP-2) in the blood were associated with the pathophysiology and development of MDD compared to healthy controls (HCs).

METHODS

This case-control study was conducted involving 50 MDD patients and 38 HCs. We performed a comprehensive assessment to match age, sex, BMI, and socio-demographic profile between the groups. The study excluded participants with chronic infection, inflammatory diseases, coexisting psychiatric disorder, history of liver and kidney diseases, and individuals who are under antipsychotic medications. A professional psychiatrist diagnosed MDD patients and evaluated HCs based on the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) criteria. The severity of depression was assessed using the Hamilton Depression (Ham-D) rating scale. Commercially available enzyme-linked immunosorbent assay (ELISA) kits were used to quantify the serum MIP-1β and MCP-2 levels.

RESULTS

The results indicated elevated serum MIP-1β levels (207.73±24.24 pg/ml) in MDD patients compared to HCs (58.77±9.14 pg/ml). This difference in concentration is positively correlated with severity of disease symptoms (r = 0.451; p<0.001). Similarly, the levels of MCP-2 were found to be elevated in patients compared to controls (143.61±19.92 vs. 56.84±4.02 pg/ml; p = 0.003), with a positive correlation with the Ham-D scores (r = 0.373; p = 0.004).

CONCLUSION

According to this study, elevated levels of MIP-1β and MCP-2 may be associated with the pathophysiology and development of MDD. These increased serum MIP-1β and MCP-2 levels could be used as risk assessment tools for MDD. The present findings urge further research and the development of therapeutic and diagnostic approaches for depression.

TNF-α promotes expression of inflammatory factors by upregulating nicotinamide adenine dinucleotide phosphate oxidase-2 expression in human gingival fibroblasts

Background/purpose

Periodontitis is a chronic infectious disease. The oxidative stress environment can cause or exacerbate the inflammation in periodontitis. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) may be the most important source of reactive oxygen species (ROS) in periodontal tissues. The pathological mechanism of periodontitis may be related to the increased ROS caused by enhanced NOX activity. The purpose was to investigate the effect of tumor necrosis factor (TNF-α) on inflammatory cytokines and ROS, and the role of NOX-2 in human gingival fibroblasts (HGFs).

Materials and methods

HGFs were cultured and divided into the normal control group (NC group) and the inflammatory model group (TNF-α group) induced by 10 ng/ml TNF-α. Thereafter, NOX-2 siRNA was used to knock down NOX-2 gene expression. Quantitative real-time PCR was applied to detect IL-6, MCP-1, and NOX-2 mRNA levels. The levels of IL-6 and MCP-1 protein were examined by ELISA. The level of NOX-2 was evaluated by Western blot. ROS expression was measured by the fluorescence microplate.

Results

The mRNA and protein expression levels of IL-6, MCP-1, and NOX-2 were significantly increased, and the expression of ROS was significantly elevated in response to 10 ng/ml TNF-α. Compared with the si-NC group, the mRNA and protein expression levels of IL-6 and MCP-1 were significantly down-regulated and ROS expression was significantly decreased in the si-NOX2 group stimulated by 10 ng/ml TNF-α.

Conclusion

TNF-α promotes the expression of NOX-2 in human gingival fibroblasts and enhances the expression of inflammatory factors and ROS in human gingival fibroblasts through the upregulation of NOX-2 partly.

Corticosteroids: A boon or bane for COVID-19 patients?

Several drugs and antibodies have been repurposed to treat COVID-19. Since the outcome of the drugs and antibodies clinical studies have been mostly inconclusive or with lesser effects, therefore the need for alternative treatments has become unavoidable. However, corticosteroids, which have a history of therapeutic efficacy against coronaviruses (SARS and MERS), might emerge into one of the pandemic's heroic characters. Corticosteroids serve an immunomodulatory function in the post-viral hyper-inflammatory condition (the cytokine storm, or release syndrome), suppressing the excessive immunological response and preventing multi-organ failure and death. Therefore, corticosteroids have been used to treat COVID-19 patients for more than last two years. According to recent clinical trials and the results of observational studies, corticosteroids can be administered to patients with severe and critical COVID-19 symptoms with a favorable risk-benefit ratio. Corticosteroids like Hydrocortisone, dexamethasone, Prednisolone and Methylprednisolone has been reported to be effective against SARS-CoV-2 virus in comparison to that of non-steroid drugs, by using non-genomic and genomic effects to prevent and reduce inflammation in tissues and the circulation. Clinical trials also show that inhaled budesonide (a synthetic corticosteroid) increases time to recovery and has the potential to reduce hospitalizations or fatalities in persons with COVID-19. There is also a brief overview of the industrial preparation of common glucocorticoids.

Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation

Simple Summary

While intrauterine devices (IUDs) are used to prevent disturbing oestrous behaviour in sport mares, their mechanism of action has not been elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and subsequently prostaglandin (PG) release and luteolysis. It has been suggested that a plastic sphere would mimic the embryo by mechanotransduction. However, there is some evidence that IUDs also cause endometrial inflammation, which might contribute to luteostasis. The aim of this study was to investigate the presence and time course of possible inflammation by evaluating changes in uterine fluid composition. On Day 10 after ovulation, events leading to COX-2 and prostaglandin F_2α (PGF_2α) inhibition start, whereas either luteolysis occurs or the corpus luteum is maintained on Day 15. Therefore, uterine lavage fluid was evaluated at two time points in inseminated mares, either pregnant or not, and in mares inserted with an IUD. On Day 10, PGF_2α concentration in the fluid was significantly lower in the IUD group than in the pregnant mare one but did not differ from the non-pregnant mare group. On Day 15, the IUD group had significantly higher levels of the modulatory cytokine IL-10 and inhibin A, which could indicate previous inflammation and resolution stage.

Abstract

Intrauterine devices (IUDs) are used in mares to suppress oestrous behaviour, but the underlying mechanism is yet to be elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and, subsequently, prostaglandin (PG) release and luteolysis. However, inflammation may also be involved. Endometrial inflammatory markers in uterine lavage fluid were measured on Day 10 (EXP 1, n = 25) and Day 15 (EXP 2, n = 27) after ovulation in inseminated mares, non-pregnant or pregnant, and in mares in which a small plastic sphere had been inserted into the uterus 4 (EXP 1) or 3 days (EXP 2) after ovulation. Uterine lavage fluid samples were analysed for nitric oxide (NO), prostaglandin E₂ (PGE₂) (only EXP 1), prostaglandin F_2α (PGF_2α), inhibin A and cytokines, and blood samples for progesterone and oestradiol. On Day 10, the concentration of PGF_2α was lower (p < 0.05) in the IUD group than in pregnant mares. The concentration of the modulatory cytokine IL-10 was significantly higher in the IUD group in comparison to non-pregnant mares, and inhibin A was significantly higher in IUD mares than in the pregnant counterparts on Day 15. The results suggest that the presence of IUD causes endometrial inflammation which is at a resolution stage on Day 15.

Corticosteroids for COVID-19

Coronavirus disease 19 (COVID-19) is placing a major burden on healthcare, economy and social systems worldwide owing to its fast spread and unacceptably high death toll. The unprecedented research effort has established the role of a deregulated immune response to the severe acute respiratory syndrome coronavirus 2, resulting in systemic inflammation. After that, the immunomodulatory approach has been placed in the top list of the research agenda for COVID-19. Corticosteroids have been used for more than 70 years to modulate the immune response in a broad variety of diseases. These drugs have been shown to prevent and attenuate inflammation both in tissues and in circulation via non-genomic and genomic effects. At the bedside, numerous observational cohorts have been published in the past months and have been inconclusive. Randomized controlled trials with subsequent high quality meta-analyses have provided moderate to strong certainty for an increased chance of survival and relief from life supportive therapy with corticosteroids given at a dose of 6 mg per day dexamethasone or equivalent doses of hydrocortisone or methylprednisolone. The corticotherapy was not associated with an increased risk of bacterial infection or of delayed viral clearance. In daily practice, physicians may be encouraged to use corticosteroids when managing patients with COVID-19 requiring oxygen supplementation.

Glucocorticoid-induced eosinopenia results from CXCR4-dependent bone marrow migration

Glucocorticoids are considered first-line therapy in a variety of eosinophilic disorders. They lead to a transient, profound decrease in circulating human eosinophils within hours of administration. The phenomenon of glucocorticoid-induced eosinopenia has been the basis for the use of glucocorticoids in eosinophilic disorders, and it has intrigued clinicians for 7 decades, yet its mechanism remains unexplained. To investigate, we first studied the response of circulating eosinophils to in vivo glucocorticoid administration in 3 species and found that the response in rhesus macaques, but not in mice, closely resembled that in humans. We then developed an isolation technique to purify rhesus macaque eosinophils from peripheral blood and performed live tracking of zirconium-89-oxine-labeled eosinophils by serial positron emission tomography/computed tomography imaging, before and after administration of glucocorticoids. Glucocorticoids induced rapid bone marrow homing of eosinophils. The kinetics of glucocorticoid-induced eosinopenia and bone marrow migration were consistent with those of the induction of the glucocorticoid-responsive chemokine receptor CXCR4, and selective blockade of CXCR4 reduced or eliminated the early glucocorticoid-induced reduction in blood eosinophils. Our results indicate that glucocorticoid-induced eosinopenia results from CXCR4-dependent migration of eosinophils to the bone marrow. These findings provide insight into the mechanism of action of glucocorticoids in eosinophilic disorders, with implications for the study of glucocorticoid resistance and the development of more targeted therapies. The human study was registered at ClinicalTrials.gov as #NCT02798523.

Feasibility, potency, and safety of growing human mesenchymal stem cells in space for clinical application

Growing stem cells on Earth is very challenging and limited to a few population doublings. The standard two-dimensional (2D) culture environment is an unnatural condition for cell growth. Therefore, culturing stem cells aboard the International Space Station (ISS) under a microgravity environment may provide a more natural three-dimensional environment for stem cell expansion and organ development. In this study, human-derived mesenchymal stem cells (MSCs) grown in space were evaluated to determine their potential use for future clinical applications on Earth and during long-term spaceflight. MSCs were flown in Plate Habitats for transportation to the ISS. The MSCs were imaged every 24-48 h and harvested at 7 and 14 days. Conditioned media samples were frozen at -80 °C and cells were either cryopreserved in 5% dimethyl sulfoxide, RNAprotect, or paraformaldehyde. After return to Earth, MSCs were characterized to establish their identity and cell cycle status. In addition, cell proliferation, differentiation, cytokines, and growth factors' secretion were assessed. To evaluate the risk of malignant transformation, the space-grown MSCs were subjected to chromosomal, DNA damage, and tumorigenicity assays. We found that microgravity had significant impact on the MSC capacity to secrete cytokines and growth factors. They appeared to be more potent in terms of immunosuppressive capacity compared to their identical ground control. Chromosomal, DNA damage, and tumorigenicity assays showed no evidence of malignant transformation. Therefore, it is feasible and potentially safe to grow MSCs aboard the ISS for potential future clinical applications.

Deriving a Boolean dynamics to reveal macrophage activation with in vitro temporal cytokine expression profiles

BACKGROUND

Macrophages show versatile functions in innate immunity, infectious diseases, and progression of cancers and cardiovascular diseases. These versatile functions of macrophages are conducted by different macrophage phenotypes classified as classically activated macrophages and alternatively activated macrophages due to different stimuli in the complex in vivo cytokine environment. Dissecting the regulation of macrophage activations will have a significant impact on disease progression and therapeutic strategy. Mathematical modeling of macrophage activation can improve the understanding of this biological process through quantitative analysis and provide guidance to facilitate future experimental design. However, few results have been reported for a complete model of macrophage activation patterns.

RESULTS

We globally searched and reviewed literature for macrophage activation from PubMed databases and screened the published experimental results. Temporal in vitro macrophage cytokine expression profiles from published results were selected to establish Boolean network models for macrophage activation patterns in response to three different stimuli. A combination of modeling methods including clustering, binarization, linear programming (LP), Boolean function determination, and semi-tensor product was applied to establish Boolean networks to quantify three macrophage activation patterns. The structure of the networks was confirmed based on protein-protein-interaction databases, pathway databases, and published experimental results. Computational predictions of the network evolution were compared against real experimental results to validate the effectiveness of the Boolean network models.

CONCLUSION

Three macrophage activation core evolution maps were established based on the Boolean networks using Matlab. Cytokine signatures of macrophage activation patterns were identified, providing a possible determination of macrophage activations using extracellular cytokine measurements.

CD11b Regulates Fungal Outgrowth but Not Neutrophil Recruitment in a Mouse Model of Invasive Pulmonary Aspergillosis

ß2 integrin receptors consist of an alpha subunit (CD11a-CD11d) and CD18 as the common beta subunit, and are differentially expressed by leukocytes. ß2 integrins are required for cell-cell interaction, transendothelial migration, uptake of opsonized pathogens, and cell signaling processes. Functional loss of CD18—termed leukocyte-adhesion deficiency type 1 (LAD1)—results in an immunocompromised state characterized by frequent occurrence of severe infections. In immunosuppressed individuals Aspergillus fumigatus is a frequent cause of invasive pulmonary fungal infection, and often occurs in patients suffering from LAD1. Here, we asked for the importance of CD11b/CD18 also termed MAC-1 which is required for phagocytosis of opsonized A. fumigatus conidia by polymorphonuclear neutrophils (PMN) for control of pulmonary A. fumigatus infection. We show that CD11b^−/− mice infected with A. fumigatus were unaffected in long term survival, similar to wild type (WT) mice. However, bronchoalveolar lavage (BAL) performed 1 day after infection revealed a higher lung infiltration of PMN in case of infected CD11b^−/− mice than observed for WT mice. BAL derived from infected CD11b^−/− mice also contained a higher amount of leukocyte-attracting CCL5 chemokine, but lower amounts of proinflammatory innate cytokines. In accordance, lung tissue of A. fumigatus infected CD11b^−/− mice was characterized by lower cellular inflammation, and a higher fungal burden. In agreement, CD11b^−/−PMN exerted lower phagocytic activity on serum-opsonized A. fumigatus conidia than WT PMN in vitro. Our study shows that MAC-1 is required for effective clearance of A. fumigatus by infiltrating PMN, and the establishment of an inflammatory microenvironment in infected lung. Enhanced infiltration of CD11b^−/− PMN may serve to compensate impaired PMN function.

Immune Effects of Corticosteroids in Sepsis

Sepsis, a life-threatening organ dysfunction, results from a dysregulated host response to invading pathogens that may be characterized by overwhelming systemic inflammation or some sort of immune paralysis. Sepsis remains a major cause of morbidity and mortality. Treatment is nonspecific and relies on source control and organ support. Septic shock, the most severe form of sepsis is associated with the highest rate of mortality. Two large multicentre trials, undertaken 15 years apart, found that the combination of hydrocortisone and fludrocortisone significantly reduces mortality in septic shock. The corticosteroids family is composed of several molecules that are usually characterized according to their glucocorticoid and mineralocorticoid power, relative to hydrocortisone. While the immune effects of glucocorticoids whether mediated or not by the intracellular glucocorticoid receptor have been investigated for several decades, it is only very recently that potential immune effects of mineralocorticoids via non-renal mineralocorticoid receptors have gained popularity. We reviewed the respective role of glucocorticoids and mineralocorticoids in counteracting sepsis-associated dysregulated immune systems.

MIP-1α and MCP-1 as salivary biomarkers in periodontal disease

Aim

Chemokines released by different host cells when exposed to the components of periodontopathic bacteria induce and maintain an inflammatory response in the periodontium. The aim of the study was to estimate the salivary levels of two chemokines, macrophage inflammatory protein-1 alpha (MIP-1α) and monocyte chemo attractant protein-1 (MCP-1) in health, gingivitis and periodontitis and to evaluate their role as reliable salivary biomarkers in discriminating gingivitis and periodontitis from health.

Methods

A cross sectional study was designed to estimate the levels of MIP-1α and MCP-1 in whole unstimulated saliva from 75 patients who were divided into healthy (Group 1, n = 25), gingivitis (Group 2, n = 25) and chronic generalized periodontitis (Group 3, n = 25). MIP-1α and MCP-1 levels were estimated by using ELISA and were correlated with clinical parameters. ROC curve analysis was done to determine the sensitivity and specificity of these biomarkers in distinguishing periodontal disease from health.

Results

Both the biomarkers were detected in all the saliva samples. There was a statistically significant difference in the concentration of both the analytes in Group 3 and Group 2 compared with Group 1 (p < 0.001). ROC curve analysis showed 100% sensitivity and specificity for MIP-1α and MCP-1 in discriminating periodontitis from health. For discriminating gingivitis from health, MIP-1α had a higher sensitivity and specificity (100% & 88% respectively) compared to MCP-1(84.1% & 80% respectively).

Conclusion

There is a substantial increase in the concentration of both MIP-1α and MCP-1 with increasing severity of periodontal disease. Both the analytes showed promising results as biomarkers for discriminating periodontal disease from health.

Crucial biological functions of CCL7 in cancer

Chemokine (C-C motif) ligand 7 (CCL7), a CC chemokine, is a chemotactic factor and attractant for various kinds of leukocytes, including monocytes and neutrophils. CCL7 is widely expressed in multiple cell types and can participate in anti-inflammatory responses through binding to its receptors to mediate the recruitment of immune cells. Abnormal CCL7 expression is associated with certain immune diseases. Furthermore, CCL7 plays a pivotal role in tumorigenesis. CCL7 promotes tumor progression by supporting the formation of the tumor microenvironment and facilitating tumor invasion and metastasis, although some studies have suggested that CCL7 has tumor suppressor effects. In this review, we summarize the currently available information regarding the influence of CCL7 on tumors.

The Role of Mitochondria and Oxidative/Antioxidative Imbalance in Pathobiology of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable disease, characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. The major risk factor of COPD, which has been proven in many studies, is the exposure to cigarette smoke. However, it is 15-20% of all smokers who develop COPD. This is why we should recognize the pathobiology of COPD as involving a complex interaction between several factors, including genetic vulnerability. Oxidant-antioxidant imbalance is recognized as one of the significant factors in COPD pathogenesis. Numerous exogenous and endogenous sources of ROS are present in pathobiology of COPD. One of endogenous sources of ROS is mitochondria. Although leakage of electrons from electron transport chain and forming of ROS are the effect of physiological functioning of mitochondria, there are various intra- and extracellular factors which may increase this amount and significantly contribute to oxidative-antioxidative imbalance. With the coexistence with impaired antioxidant defence, all these issues lead to oxidative and carbonyl stress. Both of these states play a significant role in pathobiology of COPD and may account for development of major comorbidities of this disease.

The impact of genetic factors on response to glucocorticoids therapy in IBD

Glucocorticosteroids (GCs) are used for many years as first-line drugs for the achievement of remission in exacerbations of inflammatory bowel disease (IBD). However, close to 20% of patients are resistant to GCs, and 40% of patients become dependent on GCs. The challenge of today's personalized medicine is the anticipation of the steroid therapy effects even before the initiation of treatment. As several studies show, individually variable response to GCs in population has a genetic background and may depend on gene variability encoding proteins involved in the function and metabolism of GCs. To those genes belong: NR3C1--responsible for the synthesis of GC receptor (GR); Hsp90, HSP70, STIP1, FKB5--genes of GR protein complex; ABCB1 and IPO13 coding glycoprotein p170; and importin 13--involved in GCs transport; IL1A, IL1B, IL2, IL4, IL8, IL10, TNF, and MIF--genes of the epithelial pro-inflammatory factors synthesis, which excessive activation causes steroid resistance as well as CYP3A4 and CYP3A5--encoding GCs biotransformation enzymes. This work systematizes and sums up the state of current knowledge in the field of pharmacogenetics as well as expectations for the future in the realm of individualized medicine in IBD patients treated with GC drugs.

Glucocorticoid pharmacogenetics in pediatric idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome represents the most common type of primary glomerular disease in children: glucocorticoids (GCs) are the first-line therapy, even if considerable interindividual differences in their efficacy and side effects have been reported. Immunosuppressive and anti-inflammatory effects of these drugs are mainly due to the GC-mediated transcription regulation of pro- and anti-inflammatory genes. This mechanism of action is the result of a complex multistep pathway that involves the glucocorticoid receptor and several other proteins, encoded by polymorphic genes. Aim of this review is to highlight the current knowledge on genetic variants that could affect GC response, particularly focusing on children with idiopathic nephrotic syndrome.

CCL8 and the Immune Control of Cytomegalovirus in Organ Transplant Recipients

Monitoring of cytomegalovirus cell-mediated immunity is a promising tool for the refinement of preventative and therapeutic strategies posttransplantation. Typically, the interferon-γ response to T cell stimulation is measured. We evaluated a broad range of cytokine and chemokines to better characterize the ex vivo host-response to CMV peptide stimulation. In a cohort of CMV viremic organ transplant recipients, chemokine expression-specifically CCL8 (AUC 0.849 95% CI 0.721-0.978; p = 0.003) and CXCL10 (AUC 0.841, 95% CI 0.707-0.974; p = 0.004)-was associated with control of viral replication. In a second cohort of transplant recipients at high-risk for CMV, the presence of a polymorphism in the CCL8 promoter conferred an increased risk of viral replication after discontinuation of antiviral prophylaxis (logrank hazard ratio 3.6; 95% CI 2.077-51.88). Using cell-sorting experiments, we determined that the primary cell type producing CCL8 in response to CMV peptide stimulation was the monocyte fraction. Finally, in vitro experiments using standard immunosuppressive agents demonstrated a dose-dependent reduction in CCL8 production. Chemokines appear to be important elements of the cell-mediated response to CMV infection posttransplant, as here suggested for CCL8, and translation of this knowledge may allow for the tailoring and improvement of preventative strategies.

The duality of chemokines in heart failure

The failing human heart is a bustling network of intra- and inter-cellular signals and related processes attempting to coordinate a repair mechanism for the injured or diseased myocardium. While our understanding of signaling by mode of cytokines is well understood on a systemic level, we are only now coming to elucidate the role of cytokines in cardiac self-regulation. An increasing number of studies are showing now that cardiomyocytes themselves have not only the ability but also the mandate to produce signals, and play direct roles in how these signals are interpreted. One of the families of cytokines employed by distressed cardiac tissue are chemokines. By regulating the movement of pro-inflammatory cell types to sites of injury, we see now how the myocardium responds to stress. Herein we review the participation of these inflammatory mediators and explore the delicate balance between their protective roles and damaging functions.

LPS modulates rhinovirus-induced chemokine secretion in monocytes and macrophages

Recent studies suggest that both bacteria and rhinoviruses (RVs) contribute to asthma exacerbations. We hypothesized that bacteria might alter antiviral responses early in the course of infection by modifying monocyte-lineage chemokine responses to RV infection. To test this hypothesis, human blood monocytes or bronchoalveolar lavage (BAL) macrophages were treated with RV types A016, B014, A001, and/or A002 in the presence or absence of LPS, and secretion of chemokines (CXCL10, CXCL11, CCL2, and CCL8) and IFN-α was measured by ELISA. Treatment with RV alone induced blood monocytes and BAL macrophages to secrete CXCL10, CXCL11, CCL2, and CCL8. Pretreatment with LPS significantly attenuated RV-induced CXCL10, CXCL11, and CCL8 secretion by 68-99.9% on average (P < 0.0001, P < 0.004, and P < 0.002, respectively), but did not inhibit RV-induced CCL2 from blood monocytes. Similarly, LPS inhibited RV-induced CXCL10 and CXCL11 secretion by over 88% on average from BAL macrophages (P < 0.002 and P < 0.0001, respectively). Furthermore, LPS inhibited RV-induced signal transducer and activator of transcription 1 phosphorylation (P < 0.05), as determined by immunoblotting, yet augmented RV-induced IFN-α secretion (P < 0.05), and did not diminish expression of RV target receptors, as measured by flow cytometry. In summary, major and minor group RVs strongly induce chemokine expression and IFN-α from monocytic cells. The bacterial product, LPS, specifically inhibits monocyte and macrophage secretion of RV-induced CXCL10 and CXCL11, but not other highly induced chemokines or IFN-α. These effects suggest that airway bacteria could modulate the pattern of virus-induced cell recruitment and inflammation in the airways.

Gene - Gene Interactions Among MCP Genes Polymorphisms in Asthma

Purpose

Monocyte chemoattractant proteins (MCPs) are important cytokines that involved in cellular activation and releasing of inflammatoy mediators by basophils and eosinophils in allergic disease. Some MCP gene variants implicate in asthma and monoclonal antibody for MCP-3 blocks allergic inflammations in the patients with asthma. Detection of interactions between gene and environment or between genes for complex disease such as asthma is important. We searched for an evidence of genetic effect of single nucleotide polymorphisms (SNPs) of MCP genes as well as gene - gene interactions involved in asthma.

Methods

Four hundreds asthmatics and four hundreds normal controls were enrolled. Asthma was defined as a positive bronchodilator response or positive methacholine provocation test with compatible clinical symptoms. Seven MCP gene SNPs (2 SNPs in MCP-1, 1 in MCP-2, and 4 in MCP-3) were included. Association analyses between SNP and asthma, and the tests for gene - gene interaction were performed.

Results

Strong linkage disequilibria were found among 7 MCP gene polymorphisms. There was no SNP that showed a significant association with asthma among 7 SNPs of 3 MCP genes. No haplotype was associated with asthma, either. The combination of MCP1-2518G>A, MCP2+46A>C, and MCP3+563C>T was the best predictive model for asthma as compared to the control in tests for gene - gene interaction. The MCP1-2518G>A and MCP2+46A>C was the second best predictive combination and this had the highest synergistic interaction effect on the subject's status than any other combination of polymorphisms. Complete linkages were not associated with the gene - gene interactions models.

Conclusions

MCP gene polymorphisms probably interact with each other; thus, these findings may help in developing a possible genetic marker to predict asthma.

The multiple faces of CCL13 in immunity and inflammation

CCL13/MCP-4, is a CC family chemokine that is chemoattractant for eosinophils, basophils, monocytes, macrophages, immature dendritic cells, and T cells, and its capable of inducing crucial immuno-modulatory responses through its effects on epithelial, muscular and endothelial cells. Similar to other CC chemokines, CCL13 binds to several chemokine receptors (CCR1, CCR2 and CCR3), allowing it to elicit different effects on its target cells. A number of studies have shown that CCL13 is involved in many chronic inflammatory diseases, in which it functions as a pivotal molecule involved in the selective recruitment of cell lineages to the inflamed tissues and their subsequent activation. Based on these studies, we suggest that blocking the actions of CCL13 can serve as a novel strategy for the generation of agents with anti-inflammatory activity. The main goal of this review is to present the current information about CCL13, its gene and protein structure and the roles of this chemokine during innate/adaptive immune responses in inflammatory diseases.

Y-box binding protein 1 and RNase UK114 mediate monocyte chemoattractant protein 1 mRNA stability in vascular smooth muscle cells

Monocyte chemoattractant protein 1 (MCP-1) plays a pivotal role in many inflammatory processes, including the progression of atherosclerosis and the response of the arterial wall to injury. We previously demonstrated that dexamethasone (Dex) inhibits MCP-1 mRNA accumulation in smooth muscle cells by decreasing its half-life. The effect of Dex was dependent upon the glucocorticoid receptor (GR) and independent of new transcription. Using RNA affinity and column chromatography, we have identified two proteins involved in regulating MCP-1 mRNA stability: Y-box binding protein 1 (YB-1), a multifunctional DNA/RNA-binding protein, and endoribonuclease UK114 (UK). By immunoprecipitation, YB and GR formed a complex present in equal amounts in extracts from untreated and Dex-treated cells. YB-1, UK, and GR small interfering RNA (siRNA) substantially inhibited the effect of Dex on MCP-1 mRNA accumulation. In addition, YB-1 antibody blocked the degradation of MCP-1 mRNA by cytoplasmic extracts from the Dex-treated cells. The degradative activity of extracts immunoprecipitated with antibodies to either YB-1 or GR was blocked with UK antibody. UK did not degrade MCP-1 mRNA; however, upon addition to nondegrading control extracts, it rapidly degraded MCP-1 mRNA. These studies define new roles for GR, YB-1, and UK in the formation of a molecular complex that degrades MCP-1 mRNA.

Airway smooth muscle in asthma: just a target for bronchodilation?

Airway smooth muscle (ASM) has long been recognized as the main cell type responsible for bronchial hyperresponsiveness. It has, thus, been considered as a target for bronchodilation. In asthma, however, there is a complex relationship between ASM and inflammatory cells, such as mast cells and T lymphocytes. Moreover, the increased ASM mass in asthmatic airways is one of the key features of airway remodeling. This article aims to review the main concepts about the 3 possible roles of ASM in asthma: (1) contractile tone, (2) inflammatory response, and (3) remodeling.

Ciclesonide inhibits TNFα- and IL-1β-induced monocyte chemotactic protein-1 (MCP-1/CCL2) secretion from human airway smooth muscle cells

Monocyte chemotactic protein-1 (MCP-1) is a member of the CC family of cytokines. It has monocyte and lymphocyte chemotactic activity and stimulates histamine release from basophils. MCP-1 is implicated in the pathogenesis of inflammatory diseases, including asthma. The airway smooth muscle (ASM) layer is thickened in asthma, and the growth factors and cytokines secreted by ASM cells play a role in the inflammatory response of the bronchial wall. Glucocorticoids and β₂-agonists are first-line drug treatments for asthma. Little is known about the effect of asthma treatments on MCP-1 production from human ASM cells. Here, we determined the effect of ciclesonide (a glucocorticoid) and formoterol (a β₂-agonist) on MCP-1 production from human ASM cells. TNFα and IL-1β induced MCP-1 secretion from human ASM cells. Formoterol had no effect on MCP-1 expression, while ciclesonide significantly inhibited IL-1β- and TNFα-induced MCP-1. Furthermore, ciclesonide inhibited IL-1β- and TNFα-induced MCP-1 mRNA and IL-1β- and TNFα-induced MCP-1 promoter and enhancer luciferase reporters. Western blots showed that ciclesonide had no effect on IκB degradation. Finally, ciclesonide inhibited an NF-κB luciferase reporter. Our data show that ciclesonide inhibits IL-1β- and TNFα-induced MCP-1 production from human ASM cells via a transcriptional mechanism involving inhibition of NF-κB binding.

The pivotal role of airway smooth muscle in asthma pathophysiology

Asthma is characterized by the association of airway hyperresponsiveness (AHR), inflammation, and remodelling. The aim of the present article is to review the pivotal role of airway smooth muscle (ASM) in the pathophysiology of asthma. ASM is the main effector of AHR. The mechanisms of AHR in asthma may involve a larger release of contractile mediators and/or a lower release of relaxant mediators, an improved ASM cell excitation/contraction coupling, and/or an alteration in the contraction/load coupling. Beyond its contractile function, ASM is also involved in bronchial inflammation and remodelling. Whereas ASM is a target of the inflammatory process, it can also display proinflammatory and immunomodulatory functions, through its synthetic properties and the expression of a wide range of cell surface molecules. ASM remodelling represents a key feature of asthmatic bronchial remodelling. ASM also plays a role in promoting complementary airway structural alterations, in particular by its synthetic function.

Airway smooth muscle and immunomodulation in acute exacerbations of airway disease

Airway smooth muscle (ASM) manifests a hyperresponsive phenotype in airway disorders such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Current evidence also suggests that ASM modulates immune responses by secreting mediators and expressing cell surface molecules. Such processes amplify or dampen inflammation by inflammatory cells in the airways or by altering cellular responses to viruses, bacteria, or pathogens known to exacerbate airways diseases.

Early expression of plasma CCL8 closely correlates with survival rate of acute graft-vs.-host disease in mice

OBJECTIVE

To elucidate the significance of early expression of CC-chemokine ligand motif 8 (CCL8) in mice with graft-vs.-host disease (GVHD), we investigated its induction mechanisms and correlation with overall survival rate in GVHD mice. Plasma CCL8 increases on day 5 of allogeneic transplantation, when signs of GVHD are barely detectable. Increase of allogeneic splenocytes in grafts exacerbates GVHD and leads to upregulation of plasma CCL8 on day 5. Overall survival is the gold standard in determining the severity of acute GVHD in mice, but the absence of clinical and/or pathological manifestations in the early phase make it difficult to estimate vital outcomes at this stage of allogeneic marrow transplantation.

MATERIALS AND METHODS

After lethal irradiation, BALB/c mice received bone marrow transplantation from C57BL/6 mice. Survival rate was monitored and clinical and pathological scores of GVHD were examined. Coculture of BALB/c-derived dendritic cells and C57BL/6-derived splenocytes was performed. CCL8 was measured by immunoassay.

RESULTS

The plasma CCL8 level at day 5 of transplantation was closely correlated with survival rate and clinical/pathological scores on day 14. In vitro study revealed that the BALB/c-derived dendritic cells expressed CCL8 upon stimulation of C57BL/6 CD4(+) T cells by cell interactions through major histocompatibility complex class II molecules.

CONCLUSIONS

These investigations indicate that early and preclinical expression of CCL8 in plasma predicts overall survival of GVHD mice. Together with an involvement of allo-recognition in CCL8 expression, it suggests that CCL8 plays an important role in GVHD pathology.

Does airway smooth muscle express an inflammatory phenotype in asthma?

In addition to hyperresponsiveness in asthma, airway smooth muscle (ASM) also manifests an inflammatory phenotype characterized by augmented expression of mediators that enhance inflammation, contribute to tissue remodelling and augment leucocyte trafficking and activity. Our present review summarizes contemporary understanding of ASM-derived mediators and their paracrine and autocrine actions in airway diseases.

Molecular mechanism of glucocorticoid resistance in inflammatory bowel disease

Natural and synthetic glucocorticoids (GCs) are widely employed in a number of inflammatory, autoimmune and neoplastic diseases, and, despite the introduction of novel therapies, remain the first-line treatment for inducing remission in moderate to severe active Crohn’s disease and ulcerative colitis. Despite their extensive therapeutic use and the proven effectiveness, considerable clinical evidence of wide inter-individual differences in GC efficacy among patients has been reported, in particular when these agents are used in inflammatory diseases. In recent years, a detailed knowledge of the GC mechanism of action and of the genetic variants affecting GC activity at the molecular level has arisen from several studies. GCs interact with their cytoplasmic receptor, and are able to repress inflammatory gene expression through several distinct mechanisms. The glucocorticoid receptor (GR) is therefore crucial for the effects of these agents: mutations in the GR gene (NR3C1, nuclear receptor subfamily 3, group C, member 1) are the primary cause of a rare, inherited form of GC resistance; in addition, several polymorphisms of this gene have been described and associated with GC response and toxicity. However, the GR is not self-standing in the cell and the receptor-mediated functions are the result of a complex interplay of GR and many other cellular partners. The latter comprise several chaperonins of the large cooperative hetero-oligomeric complex that binds the hormone-free GR in the cytosol, and several factors involved in the transcriptional machinery and chromatin remodeling, that are critical for the hormonal control of target genes transcription in the nucleus. Furthermore, variants in the principal effectors of GCs (e.g. cytokines and their regulators) have also to be taken into account for a comprehensive evaluation of the variability in GC response. Polymorphisms in genes involved in the transport and/or metabolism of these hormones have also been suggested as other possible candidates of interest that could play a role in the observed inter-individual differences in efficacy and toxicity. The best-characterized example is the drug efflux pump P-glycoprotein, a membrane transporter that extrudes GCs from cells, thereby lowering their intracellular concentration. This protein is encoded by the ABCB1/MDR1 gene; this gene presents different known polymorphic sites that can influence its expression and function. This editorial reviews the current knowledge on this topic and underlines the role of genetics in predicting GC clinical response. The ambitious goal of pharmacogenomic studies is to adapt therapies to a patient’s specific genetic background, thus improving on efficacy and safety rates.

Expression profiling identifies Klf15 as a glucocorticoid target that regulates airway hyperresponsiveness

Glucocorticoids (GCs), which activate GC receptor (GR) signaling and thus modulate gene expression, are widely used to treat asthma. GCs exert their therapeutic effects in part through modulating airway smooth muscle (ASM) structure and function. However, the effects of genes that are regulated by GCs on airway function are not fully understood. We therefore used transcription profiling to study the effects of a potent GC, dexamethasone, on human ASM (HASM) gene expression at 4 and 24 hours. After 24 hours of dexamethasone treatment, nearly 7,500 genes had statistically distinguishable changes in expression; quantitative PCR validation of a 40-gene subset of putative GR-regulated genes in 6 HASM cell lines suggested that the early transcriptional targets of GR signaling are similar in independent HASM lines. Gene ontology analysis implicated GR targets in controlling multiple aspects of ASM function. One GR-regulated gene, the transcription factor, Kruppel-like factor 15 (Klf15), was already known to modulate vascular smooth and cardiac muscle function, but had no known role in the lung. We therefore analyzed the pulmonary phenotype of Klf15(-/-) mice after ovalbumin sensitization and challenge. We found diminished airway responses to acetylcholine in ovalbumin-challenged Klf15(-/-) mice without a significant change in the induction of asthmatic inflammation. In cultured cells, overexpression of Klf15 reduced proliferation of HASM cells, whereas apoptosis in Klf15(-/-) murine ASM cells was increased. Together, these results further characterize the GR-regulated gene network in ASM and establish a novel role for the GR target, Klf15, in modulating airway function.

Anti-inflammatory and immunomodulatory effects of RDV-8 [C18H22N2O2S (ethyl 1-butyl-6-methyl-2-phenyl-4-thioxo-1,4-dihydropyrimidine-5-carboxylate)] in a rat model of induced pleurisy and in vitro lymphoproliferation

RDV-8 [C(18)H(22)N(2)O(2)S (ethyl 1-butyl-6-methyl-2-phenyl-4-thioxo-1,4-dihydropyrimidine-5-carboxylate)] is derived from the 4-thioxopyrimidine, and presents important clinical effects. The present study explored the RDV-8 effects in the proliferation of human peripheral blood mononuclear cells (PBMCs), as well as in a pleurisy-induced rat model. PBMCs were directly plated in four different RDV-8 concentrations (0.0125, 0.025, 0.05 and 0.1 mg/mL). RDV-8 decreased cell proliferation and monocyte chemotactic protein 1 synthesis. The interleukin 1 levels and the cytotoxic effect were not significantly affected by RDV-8 treatment. In the carrageenan-induced pleurisy model, the RDV-8 (3 mg/kg) treatment induced a significant reduction in the exudate volume, in the polymorphonuclear leukocyte migration and in the pleural exudate NO levels. The results indicate that RDV-8 may have an immunomodulatory effect, as well as anti-inflammatory actions suggesting that it could represent a new strategy in the inflammatory response modulation.

Suppression of innate immune pathology by regulatory T cells during Influenza A virus infection of immunodeficient mice

The viral infection of higher vertebrates elicits potent innate and adaptive host immunity. However, an excessive or inappropriate immune response also may lead to host pathology that often is more severe than the direct effects of viral replication. Therefore, several mechanisms exist that regulate the magnitude and class of the immune response. Here, we have examined the potential involvement of regulatory T (Treg) cells in limiting pathology induced by influenza A virus (IAV) infection. Using lymphocyte-deficient mice as hosts, we showed that Treg cell reconstitution resulted in a significant delay in weight loss and prolonged survival following infection. The adoptively transferred Treg cells did not affect the high rate of IAV replication in the lungs of lymphocyte-deficient hosts, and therefore their disease-ameliorating effect was mediated through the suppression of innate immune pathology. Mechanistically, Treg cells reduced the accumulation and altered the distribution of monocytes/macrophages in the lungs of IAV-infected hosts. This reduction in lung monocytosis was associated with a specific delay in monocyte chemotactic protein-2 (MCP-2) induction in the infected lungs. Nevertheless, Treg cells failed to prevent the eventual development of severe disease in lymphocyte-deficient hosts, which likely was caused by the ongoing IAV replication. Indeed, using T-cell-deficient mice, which mounted a T-cell-independent B cell response to IAV, we further showed that the combination of virus-neutralizing antibodies and transferred Treg cells led to the complete prevention of clinical disease following IAV infection. Taken together, these results suggested that innate immune pathology and virus-induced pathology are the two main contributors to pathogenesis during IAV infection.

MKP1 regulates the induction of MCP1 by Streptococcus pneumoniae pneumolysin in human epithelial cells

Epithelial cells act as the first line of host defense against microbes by producing a range of different molecules for clearance. Chemokines facilitate the clearance of invaders through the recruitment of leukocytes. Thus, upregulation of chemokine expression represents an important innate host defense response against invading microbes such as Streptococcus pneumoniae. In this study, we report that the expression of Monocyte Chemotactic Protein 1 (MCP1) was highly induced in response to S. pneumoniae in vitro and in vivo. Among numerous virulence factors, pneumococcal pneumolysin was found to be the major factor responsible for this induction. Furthermore, MCP1 induction was mediated by the p38 mitogen-activated protein kinase (MAPK) whose activation was controlled by MAPK phosphatase 1 (MKP1). Therefore, this study reveals novel roles of pneumolysin in mediating MKP1 expression for the regulation of MCP1 expression in human epithelial cells.

Serglycin proteoglycan deletion in mouse platelets: physiological effects and their implications for platelet contributions to thrombosis, inflammation, atherosclerosis, and metastasis

Serglycin is found in all nucleated hematopoietic cells and platelets, blood vessels, various reproductive and developmental tissues, and in chondrocytes. The serglycin knockout mouse has demonstrated that this proteoglycan is required for proper generation and function of secretory granules in several hematopoietic cells. The effects on platelets are profound, and include diminishing platelet aggregation responses and formation of platelet thrombi. This chapter will review cell-specific aspects of serglycin structure, its gene regulation, cell and tissue localization, and the effects of serglycin deletion on hematopoietic cell granule structure and function. The effects of serglycin knockout on platelets are described and discussed in detail. Rationales for further investigations into the contribution of serglycin to the known roles of platelets in thrombosis, inflammation, atherosclerosis, and tumor metastasis are presented.

Noncontractile functions of airway smooth muscle cells in asthma

Although pivotal in regulating bronchomotor tone in asthma, airway smooth muscle (ASM) also modulates airway inflammation and undergoes hypertrophy and hyperplasia, contributing to airway remodeling in asthma. ASM myocytes secrete or express a wide array of immunomodulatory mediators in response to extracellular stimuli, and in chronic severe asthma, increases in ASM mass may render the airway irreversibly obstructed. Although the mechanisms by which ASM secretes cytokines and chemokines are the same as those regulating immune cells, there exist unique ASM signaling pathways that may provide novel therapeutic targets. This review provides an overview of our current understanding of the proliferative as well as the synthetic properties of ASM.

Der p2 activates airway smooth muscle cells in a TLR2/MyD88-dependent manner to induce an inflammatory response

Der p2 is a major allergen from Dermatophagoides pteronyssinus, the main species of house dust mite and a major inducer of asthma, inducing harmful respiratory inflammatory responses by activating cells in the respiratory tract, leading to an unstable status. We hypothesize that Der p2 may induce local inflammatory responses by directly affecting airway smooth muscle (ASM) cells. In this study, we demonstrated that Der p2 raised nuclear factor-kappa B (NF-kappaB) and extracellular signal-regulated kinase (ERK) 1/2 activation and induced a high level of proinflammatory cytokines expression in primary cultured ASM cells. Der p2 activated the MyD88 signaling pathway through toll-like receptor (TLR) 2, not through TLR4. Notably, Der p2 stimulated ASM cells to increase phosphorylation of ERK1/2 and expression of c-Fos, which were also important in the T helper type 2 (Th2) immune response. These results suggest that Der p2 induces asthma through the MyD88 signaling pathway in respiratory tissue.

Synergistic up-regulation of MCP-2/CCL8 activity is counteracted by chemokine cleavage, limiting its inflammatory and anti-tumoral effects

Chemokines mediate the inflammatory response by attracting various leukocyte types. MCP-2/CC chemokine ligand 8 (CCL8) was induced at only suboptimal levels in fibroblasts and endothelial cells by IL-1beta or IFN-gamma, unless these cytokines were combined. IFN-gamma also synergized with the TLR ligands peptidoglycan (TLR2), dsRNA (TLR3) or LPS (TLR4). Under these conditions, intact MCP-2/CCL8(1-76) produced by fibroblasts was found to be processed into MCP-2/CCL8(6-75), which lacked chemotactic activity for monocytic cells. Furthermore, the capacity of MCP-2/CCL8(6-75) to increase intracellular calcium levels through CCR1, CCR2, CCR3 and CCR5 was severely reduced. However, the truncated isoform still blocked these receptors for other ligands. MCP-2/CCL8(6-75) induced internalization of CCR2, inhibited MCP-1/CCL2 and MCP-2/CCL8 ERK signaling and antagonized the chemotactic activity of several CCR2 ligands (MCP-1/CCL2, MCP-2/CCL8, MCP-3/CCL7). In contrast to MCP-3/CCL7, parvoviral delivery of MCP-2/CCL8 into B78/H1 melanoma failed to inhibit tumor growth, partially due to proteolytic cleavage into inactive MCP-2/CCL8 missing five NH(2)-terminal residues. However, in an alternative tumor model, using HeLa cells, MCP-2/CCL8 retarded tumor development. These data indicate that optimal induction and delivery of MCP-2/CCL8 is counteracted by converting this chemokine into a receptor antagonist, thereby losing its anti-tumoral potential.

Airway smooth muscle as a model for new investigative drugs in asthma

Bronchial asthma as such exists because airway smooth muscle (ASM) contracts excessively in response to various stimuli. After several decades during which research was mainly focused on airway inflammation, increasing attention is now being paid to a possible abnormal behaviour of ASM. Thus, ASM is regarded as a major target for anti-asthma treatments. This review first describes the mechanisms of ASM contraction and airway hyperresponsiveness, through cellular, animal and human models. The developments of new drugs targeting extra and/or intracellular pathway of ASM contraction are discussed.

Airway smooth muscle as an immunomodulatory cell

Although pivotal in regulating bronchomotor tone in asthma, airway smooth muscle (ASM) also modulates airway inflammation in asthma. ASM myocytes secrete or express a wide array of immunomodulatory mediators in response to extracellular stimuli, and in chronic severe asthma, increases in ASM mass may also render the airway irreversibly obstructed. Although the mechanisms by which ASM secretes cytokines and chemokines are shared with those regulating immune cells, there exist unique ASM signaling pathways that may provide novel therapeutic targets. This review provides an overview of our current understanding of the proliferative as well as synthetic properties of ASM.

The effect of interleukin-4 and amphiregulin on the proliferation of human airway smooth muscle cells and cytokine release

Airway smooth muscle (ASM) hyperplasia and angiogenesis are important features associated with airway remodeling. We investigated the effect of IL-4 and amphiregulin, an epidermal growth factor family member, on the proliferation of human ASM cells and on the release of vascular endothelial growth factor (VEGF) and monocyte chemotactic protein (MCP)-1 from human ASM cells. Human ASM cells were growth-arrested for 48 hr and incubated with platelet-derived growth factor (PDGF)- BB, interleukin (IL)-4, amphiregulin, and VEGF to evaluate cell proliferation. The cells were treated with PDGF, IL-4 and amphiregulin to evaluate the release of VEGF, MCP-1. IL-4 suppressed unstimulated and PDGF-stimulated ASM cell proliferation. Amphiregulin stimulated ASM cell proliferation in a dose-dependent manner. VEGF did not have any influence on ASM cell proliferation. IL-4 stimulated VEGF secretion by the ASM cells in a dose-dependent manner and showed added stimulatory effects when co-incubated with PDGF. Amphiregulin did not promote VEGF secretion. IL-4 and amphiregulin showed no stimulatory effects on MCP-1 secretion. The results of this study showed that IL-4 had bifunctional effects on airway remodeling, one was the suppression of the proliferation of the ASM cells and the other was the promotion of VEGF release by the ASM cells, and amphiregulin can promote human ASM cell proliferation.

Gammaherpesvirus modulation of mouse adenovirus type 1 pathogenesis

Immune function is likely to be shaped by multiple infections over time. Infection with one pathogen can confer cross-protection against heterologous pathogens. We tested the hypothesis that latent murine gammaherpesvirus 68 (gammaHV68) infection modulates host inflammatory responses and susceptibility to mouse adenovirus type 1 (MAV-1). Mice were infected intranasally (i.n.) with gammaHV68. 21 days later, they were infected i.n. with MAV-1. We assessed cytokine and chemokine expression by quantitative reverse transcriptase real-time PCR, cellular inflammation by histology, and viral loads by quantitative real-time PCR. Previous gammaHV68 infection led to persistently upregulated IFN-gamma in lungs and spleen and persistently upregulated CCL2 and CCL5 in the lungs. Previous gammaHV68 infection amplified MAV-1-induced CCL5 upregulation and cellular inflammation in the lungs. Previous gammaHV68 infection was associated with lower MAV-1 viral loads in the spleen but not the lung. There was no significant effect of previous gammaHV68 on IFN-gamma expression or MAV-1 viral loads when the interval between infections was increased to 44 days. In summary, previous gammaHV68 infection modulated lung inflammatory responses and decreased susceptibility to a heterologous virus in an organ- and time-dependent manner.

Monocyte chemoattractant protein-1 (CCL-2) integrates mechanical and endocrine signals that mediate term and preterm labor

Recent evidence suggests that leukocytes infiltrate uterine tissues at or around the time of parturition, implicating inflammation as a key mechanism of human labor. MCP-1 (also known as C-C chemokine motif ligand 2, CCL-2) is a proinflammatory cytokine that is up-regulated in human myometrium during labor. Myometrium was collected from pregnant rats across gestation and at labor. Total RNA and proteins were subjected to real-time PCR and ELISA, respectively. Ccl-2 gene and protein expression was significantly up-regulated in the gravid rat myometrium before and during labor, which might suggest that it is regulated positively by mechanical stretch of the uterus imposed by the growing fetus and negatively by physiological withdrawal of progesterone (P4). We confirmed in vivo that: 1) administration of P4 receptor antagonist RU486 induced an increase in Ccl-2 mRNA and preterm labor, whereas 2) artificial maintenance of elevated P4 levels at late gestation caused a significant decrease in gene expression and blocked labor; 3) Ccl-2 was elevated specifically in the gravid horn of unilaterally pregnant rats suggesting that mechanical strain imposed by the growing fetus controls its expression in the myometrium; 4) in vitro static mechanical stretch of primary rat myometrial smooth muscle cells (25% elongation) induced a release of Ccl-2 protein, which was repressed by pretreatment with P4 (1 microM); and 5) stretch enhanced their monocyte chemoattractant activity. These data indicate that Ccl-2 protein serves to integrate mechanical and endocrine signals contributing to uterine inflammation and the induction of labor and thus may represent a novel target for therapeutic prevention of preterm labor in humans.

Posttraumatic stress and immune dissonance

Stress or neuroendocrine response usually occurs soon after trauma, which is central to the maintenance of post-traumatic homeostasis. Immune inflammatory response has been recognized to be a key element both in the pathogenesis of post-traumatic complications and in tissue repair. Despite the existence of multiple and intricate interconnected neuroendocrine pathways, the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system have been considered to be the most important in trauma. Although the short-term and appropriate activation of these stress responses is vital to the host's adaptation, prolonged duration and exaggerative magnitude of their activity leads to deleterious effects on immune function in trauma, causing immune dissonance. The overall appropriate and controlled activation and termination of the neuroendocrine responses that mediate the necessary physiological functions involved in maintaining and restoring homeostasis in the event of trauma are of critical importance. This review will describe the effects of some important neuroendocrine responses on immune system. Present evidences indicate that the neuroendocrine and immune systems form a cohesive and integrated early host response to trauma, and identify areas for further research to fully elucidate the regulatory role of neuroendocrine system in trauma.

Interleukin-4 activates large-conductance, calcium-activated potassium (BKCa) channels in human airway smooth muscle cells

Large-conductance, calcium-activated potassium (BK(Ca)) channels are regulated by voltage and near-membrane calcium concentrations and are determinants of membrane potential and excitability in airway smooth muscle cells. Since the T helper-2 (Th2) cytokine, interleukin (IL)-4, is an important mediator of airway inflammation, we investigated whether IL-4 rapidly regulated BK(Ca) activity in normal airway smooth muscle cells. On-cell voltage clamp recordings were made on subconfluent, cultured human bronchial smooth muscle cells (HBSMC). Interleukin-4 (50 ng ml(-1)), IL-13 (50 ng ml(-1)) or histamine (10 microm) was added to the bath during the recordings. Immunofluorescence studies with selective antibodies against the alpha and beta1 subunits of BK(Ca) were also performed. Both approaches demonstrated that HBSMC membranes contained large-conductance channels (>200 pS) with both calcium and voltage sensitivity, all of which is characteristic of the BK(Ca) channel. Histamine caused a rapid increase in channel activity, as expected. A new finding was that perfusion with IL-4 stimulated rapid, large increases in BK(Ca) channel activity (77.2 +/- 63.3-fold increase, P < 0.05, n = 18). This large potentiation depended on the presence of external calcium. In contrast, IL-13 (50 ng ml(-1)) had little effect on BK(Ca) channel activity, but inhibited the effect of IL-4. Thus, HBSMC contain functional BK(Ca) channels whose activity is rapidly potentiated by the cytokine, IL-4, but not by IL-13. These findings are consistent with a model in which IL-4 rapidly increases near-membrane calcium concentrations to regulate BK(Ca) activity.

Endogenous lipid mediators in the resolution of airway inflammation

Acute inflammation in the lung is fundamentally important to host defence, but chronic or excessive inflammation leads to several common respiratory diseases, including asthma and acute respiratory distress syndrome. The resolution of inflammation is an active process. In health, events at the onset of acute inflammation establish biosynthetic circuits for specific chemical mediators that later serve as agonists to orchestrate a return to tissue homeostasis. In addition to an overabundance of pro-inflammatory stimuli, pathological inflammation can also result from defects in resolution signalling. The understanding of anti-inflammatory, pro-resolution molecules and their counter-regulatory signalling pathways is providing new insights into the molecular pathophysiology of lung disease and opportunities for the design of therapeutic strategies. In the present review, the growing family of lipid mediators of resolution is examined, including lipoxins, resolvins, protectins, cyclopentenones and presqualene diphosphate. Roles are uncovered for these compounds, or their structural analogues, in regulating airway inflammation.

Monocyte chemotactic protein-1 and its role in insulin resistance

PURPOSE OF REVIEW

In obesity, there is a strong link between increased adipose tissue mass and development of insulin resistance in tissues such as liver and muscle. Under these conditions, adipose tissue synthesizes various pro-inflammatory chemokines such as monocyte chemotactic protein-1. This review provides a summary of recent knowledge on the role of monocyte chemotactic protein-1 in adipose tissue inflammation and insulin resistance.

RECENT FINDINGS

Monocyte chemotactic protein-1 is a proinflammatory adipokine that is believed to play a role in the pathogenesis of obesity and diabetes. New in-vitro data demonstrate that monocyte chemotactic protein-1 has the ability to induce insulin resistance in adipocytes and skeletal muscle cells. By using mice that either overexpress monocyte chemotactic protein-1 or are deficient in monocyte chemotactic protein-1 or its receptor, exciting new insights have been obtained into the role of monocyte chemotactic protein-1 in adipose tissue inflammation and insulin resistance.

SUMMARY

Monocyte chemotactic protein-1 is an adipokine with insulin-resistance-inducing capacity that is related to increased adipose tissue mass in obesity and insulin resistance. It plays an important role in adipose tissue inflammation by recruiting macrophages into fat. Monocyte chemotactic protein-1 is thus a therapeutic target, and may represent an important factor linking adipose tissue inflammation, obesity and type 2 diabetes.