Identification of a novel regulatory mechanism for the disease associated protein, uPAR

Expression quantitative trait loci (eQTLs), as determined through a series of statistical association studies collectively known as genome-wide association (GWA) studies, have provided us with a hypothesis free approach for the investigation into regulatory loci for disease and disease-associated proteins. This has led to the identification of multiple novel gene-disease interactions, especially in the field of respiratory medicine. This review describes the case study of a GWA approach in order to identify eQTLs for the soluble form of the urokinase plasminogen activator receptor (uPAR), a protein associated with obstructive respiratory disease. Molecular and cellular investigations based on the eQTLs identified for this GWA study has led to the identification of a novel regulatory mechanism with implications in the disease processes with which this protein is associated. This highlights the potential of eQTLs defined associations in the identification of novel mechanisms, with implications in disease.peer-reviewe

Interleukin-4 receptor alpha gene variants and allergic disease

The interleukin-4 (IL-4) signalling cascade has been identified as a pathway potentially important in the development of asthma. Genetic variants within this signalling pathway might contribute to the risk of developing asthma in a given individual. A number of polymorphisms have been described within the IL-4 receptor alpha (IL-4Ralpha) gene. In addition polymorphism occurs in the promoter for the IL-4 gene itself. This commentary accompanies a paper by C Ober et al describing the contribution of IL-4Ralpha polymorphism to susceptibility to asthma and atopy in the Hutterite population and other outbred populations collected during the collaborative studies on the genetics of asthma (CSGA) programm

Pharmacogenetics, pharmacogenomics and airway disease

The availability of a draft sequence for the human genome will revolutionise research into airway disease. This review deals with two of the most important areas impinging on the treatment of patients: pharmacogenetics and pharmacogenomics. Considerable inter-individual variation exists at the DNA level in targets for medication, and variability in response to treatment may, in part, be determined by this genetic variation. Increased knowledge about the human genome might also permit the identification of novel therapeutic targets by expression profiling at the RNA (genomics) or protein (proteomics) level. This review describes recent advances in pharmacogenetics and pharmacogenomics with regard to airway diseas

Real time analysis of β2-adrenoceptor-mediated signaling kinetics in Human Primary Airway Smooth Muscle Cells reveals both ligand and dose dependent differences

BACKGROUND: β(2)-adrenoceptor agonists elicit bronchodilator responses by binding to β(2)-adrenoceptors on airway smooth muscle (ASM). In vivo, the time between drug administration and clinically relevant bronchodilation varies significantly depending on the agonist used. Our aim was to utilise a fluorescent cyclic AMP reporter probe to study the temporal profile of β(2)-adrenoceptor-mediated signaling induced by isoproterenol and a range of clinically relevant agonists in human primary ASM (hASM) cells by using a modified Epac protein fused to CFP and a variant of YFP. METHODS: Cells were imaged in real time using a spinning disk confocal system which allowed rapid and direct quantification of emission ratio imaging following direct addition of β(2)-adrenoceptor agonists (isoproterenol, salbutamol, salmeterol, indacaterol and formoterol) into the extracellular buffer. For pharmacological comparison a radiolabeling assay for whole cell cyclic AMP formation was used. RESULTS: Temporal analysis revealed that in hASM cells the β(2)-adrenoceptor agonists studied did not vary significantly in the onset of initiation. However, once a response was initiated, significant differences were observed in the rate of this response with indacaterol and isoproterenol inducing a significantly faster response than salmeterol. Contrary to expectation, reducing the concentration of isoproterenol resulted in a significantly faster initiation of response. CONCLUSIONS: We conclude that confocal imaging of the Epac-based probe is a powerful tool to explore β(2)-adrenoceptor signaling in primary cells. The ability to analyse the kinetics of clinically used β(2)-adrenoceptor agonists in real time and at a single cell level gives an insight into their possible kinetics once they have reached ASM cells in vivo

Clonally expanded human airway smooth muscle cells exhibit morphological and functional heterogeneity

Background: Mesenchyme-derived airway cell populations including airway smooth muscle (ASM) cells, fibroblasts and myofibroblasts play key roles in the pathogenesis of airway inflammation and remodeling. Phenotypic and functional characterisation of these cell populations are confounded by their heterogeneity in vitro. It is unclear which mechanisms underlie the creation of these different sub-populations. The study objectives were to investigate whether ASM cells are capable of clonal expansion and if so (i) what proportion possess this capability and (ii) do clonal populations exhibit variation in terms of morphology, phenotype, proliferation rates and pro-relaxant or pro-contractile signaling pathways. Methods: Early passage human ASM cells were subjected to single-cell cloning and their doubling time was recorded. Immunocytochemistry was performed to assess localization and levels of markers previously reported to be specifically associated with smooth muscle or fibroblasts. Finally functional assays were used to reveal differences between clonal populations specifically assessing mitogen-induced proliferation and pro-relaxant and pro-contractile signaling pathways. Results: Our studies provide evidence that a high proportion (58%) of single cells present within early passage human ASM cell cultures have the potential to create expanded cell populations. Despite being clonally-originated, morphological heterogeneity was still evident within these clonal populations as assessed by the range in expression of markers associated with smooth muscle cells. Functional diversity was observed between clonal populations with 10 μM isoproterenol-induced cyclic AMP responses ranging from 1.4 - 5.4 fold cf basal and bradykinin-induced inositol phosphate from 1.8 - 5.2 fold cf basal. Conclusion: In summary we show for the first time that primary human ASM cells are capable of clonal expansion and that the resulting clonal populations themselves exhibit phenotypic plasticity

Genetic risk factors for the development of pulmonary disease identified by genome-wide association

Chronic respiratory diseases are a major cause of morbidity and mortality. Asthma and chronic obstructive pulmonary disease (COPD) combined affect over 500 million people worldwide. While environmental factors are important in disease progression, asthma and COPD have long been known to be heritable with genetic components playing an important role in the risk of developing disease. Identification of genetic variation contributing to disease progression is important for a number of reasons including identification of risk alleles, understanding underlying disease mechanisms and development of novel therapies. Genome?wide association studies (GWAS) have been successful in identifying many loci associated with lung function, COPD and asthma. In recent years, meta?analyses and improved imputation have facilitated the growth of GWAS in terms of numbers of subjects and the number of single nucleotide polymorphisms (SNP) that can be interrogated. As a consequence, there has been a significant increase in the number of signals associated with asthma, COPD and lung function. SNP that have shown association with lung function reassuringly show a significant overlap with SNP associated with COPD giving a glimpse at pathways that may be involved in COPD mechanisms including genes in, for example, developmental pathways. In asthma, association signals are often in or near genes involved in both adaptive and innate immune response pathways, epithelial cell homeostasis and airway structural changes. The challenges now are translating these genetic signals into a new understanding of lung biology, understanding how variants impact health and disease and how they may provide opportunities for therapeutic intervention

Desynchronization of pathological low-frequency brain activity by the hypnotic drug zolpidem.

Reports of the beneficial effects of the hypnotic imidazopyridine, zolpidem, described in persistent vegetative state^1, 2^ have been replicated recently in brain-injured and cognitively impaired patients^3-7^. Previous single photon emission computed tomography (SPECT) studies have suggested that sub-sedative doses of zolpidem increased regional cerebral perfusion in affected areas^5, 8^, implying enhanced neuronal metabolic activity; which has led to speculation that zolpidem 'reawakens' functionally dormant cortex. However, a neuronal mechanism by which this hypnotic drug affords benefits to brain injured patients has yet to be demonstrated. Here, we report the action of sub-sedative doses of zolpidem on neuronal network oscillatory activity in human brain, measured using pharmaco-magnetoencephalography (pharmaco-MEG). Study participant JP suffered a stroke in 1996, causing major damage to the left hemisphere that impaired aspects of both motor and cognitive function. Pharmaco-MEG analyses revealed robust and persistent pathological theta (4-10Hz) and beta (15-30Hz) oscillations within the lesion penumbra and surrounding cortex. Administration of zolpidem (5mg) reduced the power of pathological theta and beta oscillations in all regions of the lesioned hemisphere. This desynchronizing effect correlated well with zolpidem uptake (occurring approximately 40 minutes after acute administration) and was coincident with marked improvements in cognitive and motor function. Control experiments revealed no effect of placebo, while a structurally unrelated hypnotic, zopiclone, administered at a comparable dose (3.5mg) elicited widespread increases in cortical oscillatory power in the beta (15-30Hz) band without functional improvement. These results suggest that in JP, specific motor and cognitive impairments are related to increased low-frequency oscillatory neuronal network activity. Zolpidem is unique amongst hypnotic drugs in its ability to desynchronize such pathological low-frequency activity, thereby restoring cognitive function

In the Shadow of the Tower: The View of the Undergraduate Experience

This paper reports the initial findings of a survey (N=388) conducted in Winter 1991 focusing on the quality of the academic experience for Arts and Science students at a medium size post-secondary institution in eastern Canada. Our purposes are: 1) to set out the context in which undergraduates conduct their academic work, 2) to document what their experience entails, and 3) to present some of their perceptions of the higher education process. While most students have vocational goals in mind, they are also keenly interested in acquiring a solid general education. Undergraduates attend most of their classes, are heavily committed to completing their programs, and work quite diligently in pursuit of their goals in the face of what many of them consider to be heavy workloads. They are not, however, completely satisfied with the services that they receive in return for their tuition fees and for Canadians' tax dollars. While satisfaction levels vary with the type of services provided, it is clear that there does exist substantial room in which institutions can make improvements. Specifically, our data suggest that the primary goals of universities seeking to better the undergraduate experience should be to encourage more effective teaching and its evaluation, to reduce class sizes, to increase formal and informal interaction among faculty members and students, to improve the quality of academic advising, and to support the creation of more equitable financial assistance programs for students.Cet article présente les premiers résultats d'une enquête (N=388) menée durant l'hiver 1991 portant sur la qualité de l'expérience universitaire d'étudiants en arts et en sciences inscrits à une institution de moyenne importance dans l'est du Canada. Nos intentions sont: 1) d'établir le contexte dans lequel les étudiants accomplissent leur travail scolaire, 2) de documenter en quoi consiste cette expérience et 3) de décrire quelques-unes de leurs impressions sur le système d'éducation supérieure. Bien que la plupart des étudiants poursuivent des buts professionnels, ils s'intéressent aussi vivement à acquérir une éducation générale à bases solides. Les étudiants de premier cycle assistent à la plupart de leurs cours, se sont voués à compléter leurs études, et travaillent diligemment afin de réaliser leurs buts malgré ce que beaucoup d'entre eux estiment être des programmes exigeants. Toutefois, ils ne sont pas entièrement satisfaits des services qu'ils reçoivent en échange de leurs frais de scolarité et des impôts prélevés aux Canadiens. Alors que le degré de satisfaction varie selon les services offerts, il est clair que des améliorations s'imposent dans plusieurs domaines. Plus précisément, nos donnés suggèrent que les universités cherchant à améliorer l'expérience des étudiants au niveau du premier cycle devraient se proposer comme buts prioritaires d'encourager un enseignement plus efficace et de mieux l'évaluer, de réduire la taille des classes, de favoriser l'interaction formelle et informelle entre les professeurs et les étudiants, d'améliorer la qualité des services d'orientation scolaire, et de promouvoir la création de programmes d'aide financière plus équitable pour les étudiants

The Optical/Near-IR Colors of Broad Absorption Line Quasars, Including the Candidate Radio-Loud BAL Quasar 1556+3517

A candidate radio-loud broad absorption line quasar (RLBAL) has been reported by Becker et al. (1997). We present JHK observations of this object and three other radio-detected BALs taken with the new Michigan-Dartmouth-MIT/Ohio State/Aladdin IR Camera (MOSAIC) on the KPNO 4-meter. The candidate RLBAL 1556+3517 has B-K=6.63, redder than all but one or two known z>1 quasars. This strongly suggests the observed continuum of this quasar is reddened by dust. Even when this extreme reddening is taken into account 1556+3517 is still probably radio-loud, although near-IR spectroscopy to measure its Balmer decrement will be needed to verify this. In addition, since it is a flat-spectrum object, VLBI observations to determine the extent (if any) to which beaming affects our estimate of its radio luminosity will be needed before 1556+3517 can be unequivocally declared a radio-loud BAL. We also use our data and data from the literature to show that optically selected BALs as a class have B-K colors consistent with the observed distribution for optically selected quasars as a whole. Thus there is currently no evidence that the tendency of optically selected BALs to be preferentially radio-intermediate (Hooper, Francis, & Impey 1993) is due to extinction artificially lowering estimated BAL optical luminosities. However, as most quasar surveys, both radio and optical, would be insensitive to a population of reddened radio-quiet BALs, the existence of a large population of reddened BALs similar to 1556+3517 cannot yet be ruled out.Comment: Accepted to ApJ Letters; 10 pages including 1 figure and 2 tables. This version somewhat revised from initial submission, with a better figur