Proteinase-Activated Receptor-1, CCL2 and CCL7 Regulate Acute Neutrophilic Lung Inflammation

PAR1 plays a central role in mediating the interplay between coagulation and inflammation, but its role in regulating acute neutrophilic inflammation is unknown. We report that antagonism of PAR1 was highly effective at reducing acute neutrophil accumulation in a mouse model of LPS-induced lung inflammation. PAR1 antagonism also reduced alveolar-capillary barrier disruption in these mice. This protection was associated with a reduction in the expression of the chemokines CCL2 and CCL7, but not the pro-inflammatory cytokines TNF and IL-6 or the classic neutrophil chemoattractants CXCL1 and CXCL2. Antibody neutralisation of CCL2 and CCL7 significantly reduced LPS-induced total leukocyte and neutrophil accumulation, recovered from the bronchoalveolar lavage fluid of challenged mice. Immunohistochemical analysis revealed CCL2 predominantly localised to alveolar macrophages and pulmonary epithelial cells, while CCL7 was restricted to the pulmonary epithelium. In keeping with these observations, the intranasal administration of rCCL2 and rCCL7 led to the accumulation of neutrophils within the lung airspaces of naïve mice in the absence of any underlying inflammation. Flow cytometry analysis further demonstrated an increase in Ly6Ghi neutrophils expressing the chemokine receptors CCR1 and CCR2 isolated from mouse lungs compared to circulating neutrophils. Conversely, the expression of CXCR2 decreased on neutrophils isolated from the lung compared to circulating neutrophils. Furthermore, this switch in chemokine receptor expression was accentuated following acute LPS-induced lung inflammation. Collectively, these findings reveal a novel role for PAR1 and the chemokines CCL2 and CCL7 during the early events of acute neutrophilic inflammation

Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media

In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application

Psychological determinants of whole-body endurance performance

Background: No literature reviews have systematically identified and evaluated research on the psychological determinants of endurance performance, and sport psychology performance-enhancement guidelines for endurance sports are not founded on a systematic appraisal of endurance-specific research. Objective: A systematic literature review was conducted to identify practical psychological interventions that improve endurance performance and to identify additional psychological factors that affect endurance performance. Additional objectives were to evaluate the research practices of included studies, to suggest theoretical and applied implications, and to guide future research. Methods: Electronic databases, forward-citation searches, and manual searches of reference lists were used to locate relevant studies. Peer-reviewed studies were included when they chose an experimental or quasi-experimental research design, a psychological manipulation, endurance performance as the dependent variable, and athletes or physically-active, healthy adults as participants. Results: Consistent support was found for using imagery, self-talk, and goal setting to improve endurance performance, but it is unclear whether learning multiple psychological skills is more beneficial than learning one psychological skill. The results also demonstrated that mental fatigue undermines endurance performance, and verbal encouragement and head-to-head competition can have a beneficial effect. Interventions that influenced perception of effort consistently affected endurance performance. Conclusions: Psychological skills training could benefit an endurance athlete. Researchers are encouraged to compare different practical psychological interventions, to examine the effects of these interventions for athletes in competition, and to include a placebo control condition or an alternative control treatment. Researchers are also encouraged to explore additional psychological factors that could have a negative effect on endurance performance. Future research should include psychological mediating variables and moderating variables. Implications for theoretical explanations of endurance performance and evidence-based practice are described

A functional AT/G polymorphism in the 5'-untranslated region (UTR) of SETDB2 in the IgE locus on human chromosome 13q14

The immunoglobulin E (IgE)-associated locus on human chromosome 13q14 influencing asthma-related traits contains the genes PHF11 and SETDB2. SETDB2 is located in the same linkage disequilibrium region as PHF11 and polymorphisms within SETDB2 have been shown to associate with total serum IgE levels. In this report, we sequenced the 15 exons of SETDB2 and identified a single previously ungenotyped mutation (AT/G, rs386770867) in the 5′-untranslated region of the gene. The polymorphism was found to be significantly associated with serum IgE levels in our asthma cohort (P=0.0012). Electrophoretic mobility shift assays revealed that the transcription factor Ying Yang 1 binds to the AT allele, whereas SRY (Sex determining Region Y) binds to the G allele. Allele-specific transcription analysis (allelotyping) was performed in 35 individuals heterozygous for rs386770867 from a panel of 200 British families ascertained through probands with severe stage 3 asthma. The AT allele was found to be significantly overexpressed in these individuals (P=1.26 × 10(−21)). A dual-luciferase assay with the pGL3 luciferase reporter gene showed that the AT allele significantly affects transcriptional activities. Our results indicate that the IgE-associated AT/G polymorphism (rs386770867) regulates transcription of SETDB2

Candidate Causal Regulatory Effects by Integration of Expression QTLs with Complex Trait Genetic Associations

The recent success of genome-wide association studies (GWAS) is now followed by the challenge to determine how the reported susceptibility variants mediate complex traits and diseases. Expression quantitative trait loci (eQTLs) have been implicated in disease associations through overlaps between eQTLs and GWAS signals. However, the abundance of eQTLs and the strong correlation structure (LD) in the genome make it likely that some of these overlaps are coincidental and not driven by the same functional variants. In the present study, we propose an empirical methodology, which we call Regulatory Trait Concordance (RTC) that accounts for local LD structure and integrates eQTLs and GWAS results in order to reveal the subset of association signals that are due to cis eQTLs. We simulate genomic regions of various LD patterns with both a single or two causal variants and show that our score outperforms SNP correlation metrics, be they statistical (r2) or historical (D'). Following the observation of a significant abundance of regulatory signals among currently published GWAS loci, we apply our method with the goal to prioritize relevant genes for each of the respective complex traits. We detect several potential disease-causing regulatory effects, with a strong enrichment for immunity-related conditions, consistent with the nature of the cell line tested (LCLs). Furthermore, we present an extension of the method in trans, where interrogating the whole genome for downstream effects of the disease variant can be informative regarding its unknown primary biological effect. We conclude that integrating cellular phenotype associations with organismal complex traits will facilitate the biological interpretation of the genetic effects on these traits

Smoking among morbidly obese patients

<p>Abstract</p> <p>Background</p> <p>Smokers usually have a lower Body Mass Index (BMI) when compared to non-smokers. Such a relationship, however, has not been fully studied in obese and morbidly obese patients. The objective of this study was to evaluate the relationship between smoking and BMI among obese and morbidly obese subjects.</p> <p>Methods</p> <p>In a case-control study design, 1022 individuals of both genders, 18-65 years of age, were recruited and grouped according to their smoking status (smokers, ex-smokers, and non-smokers) and nutritional state according to BMI (normal weight, overweight, obese, and morbidly obese).</p> <p>Results</p> <p>No significant differences were detected in the four BMI groups with respect to smoking status. However, there was a trend towards a higher frequency of smokers among the overweight, obese, and morbidly obese subjects compared to normal weight individuals (p = 0.078). In a logistic regression, after adjusting for potential confounders, morbidly obese subjects had an adjusted OR of 2.25 (95% CI, 1.52-3.34; p < 0.001) to be a smoker when compared to normal weight individuals.</p> <p>Discussion</p> <p>In this sample, while the frequency of smokers diminished in normal weight subjects as the BMI increased, such a trend was reversed in overweight, obese, and morbidly obese patients. In the latter group, the prevalence of smokers was significantly higher compared to the other groups. A patient with morbid obesity had a 2-fold increased risk of becoming a smoker. We speculate that these finding could be a consequence of various overlapping risk behaviors because these patients also are generally less physically active and prefer a less healthy diet, in addition to having a greater alcohol intake in relation to their counterparts. The external validity of these findings must be confirmed.</p

Tumor Necrosis Factor-α +489G/A gene polymorphism is associated with chronic obstructive pulmonary disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by a chronic inflammatory process, in which the pro-inflammatory cytokine Tumor Necrosis Factor (TNF)-α is considered to play a role. In the present study the putative involvement of TNF-α gene polymorphisms in pathogenesis of COPD was studied by analysis of four TNF-α gene polymorphisms in a Caucasian COPD population. METHODS: TNF-α gene polymorphisms at positions -376G/A, -308G/A, -238G/A, and +489G/A were examined in 169 Dutch COPD patients, who had a mean forced expiratory volume in one second (FEV1) of 37 ± 13%, and compared with a Dutch population control group of 358 subjects. RESULTS: The data showed that the TNF-α +489G/A genotype frequency tended to be different in COPD patients as compared to population controls, which was due to an enhanced frequency of the GA genotype. In line herewith, carriership of the minor allele was associated with enhanced risk of development of COPD (odds ratio = 1.9, p = 0.009). The other TNF-α gene polymorphisms studied revealed no discrimination between patients and controls. No differences in the examined four TNF-α polymorphisms were found between subtypes of COPD, which were stratified for the presence of radiological emphysema. However, comparison of the COPD subtypes with controls showed a significant difference in the TNF-α +489G/A genotype in patients without radiological emphysema (χ(2)-test: p < 0.025 [Bonferroni adjusted]), while no differences between COPD patients with radiological emphysema and controls were observed. CONCLUSION: Based on the reported data, it is concluded that COPD, and especially a subgroup of COPD patients without radiological emphysema, is associated with TNF-α +489G/A gene polymorphism

The role of ALOX5AP, LTA4H and LTB4R polymorphisms in determining baseline lung function and COPD susceptibility in UK smokers

<p>Abstract</p> <p>Background</p> <p>We have previously shown evidence that polymorphisms within genes controlling leukotriene B₄(LTB₄) production (<it>ALOX5AP </it>and <it>LTA4H</it>) are associated with asthma susceptibility in children. Evidence also suggests a potential role of LTB₄in COPD disease mechanisms including recruitment of neutrophils to the lung. The aim of the current study was to see if these SNPs and those spanning the receptor genes for LTB₄(<it>LTB4R1 </it>and <it>LTB4R2</it>) influence baseline lung function and COPD susceptibility/severity in smokers.</p> <p>Methods</p> <p>Eight <it>ALOX5AP</it>, six <it>LTA4H </it>and six <it>LTB4R </it>single nucleotide polymorphisms (SNPs) were genotyped in a UK Smoking Cohort (n = 992). Association with baseline lung function (FEV₁and FEV₁/FVC ratio) was determined by linear regression. Logistic regression was used to compare smoking controls (n = 176) with spirometry-defined COPD cases (n = 599) and to more severe COPD cases (GOLD stage 3 and 4, n = 389).</p> <p>Results</p> <p>No association with <it>ALOX5AP</it>, <it>LTA4H </it>or <it>LTB4R </it>survived correction for multiple testing. However, we showed modest association with <it>LTA4H </it>rs1978331C (intron 11) with increased FEV₁(p = 0.029) and with increased FEV₁/FVC ratio (p = 0.020).</p> <p>Conclusions</p> <p>These data suggest that polymorphisms spanning <it>ALOX5AP</it>, <it>LTA4H </it>and the <it>LTB4R </it>locus are not major determinants of baseline lung function in smokers, but provide tentative evidence for <it>LTA4H </it>rs1978331C (intron 11) in determining baseline FEV₁and FEV₁/FVC ratio in Caucasian Smokers in addition to our previously identified role in asthma susceptibility.</p