CD148: a positive regulator of GPVI and α\alphaIIβ\beta3 proximal signalling in platelets

Platelets are small anucleate blood cells that plug holes in damage blood vessels. They do so by adhering to exposed extracellular matrix proteins at sites of injury and aggregating together. Platelet responsiveness to injury is controlled by a diverse repertoire of surface receptors that can be divided into two broad categories based on how they signal; the tyrosine kinased-linked receptors and the G protein-coupled receptors (GPCRs). There has been much work on elucidating the functions of tyrosine kinases in platelets, whereas protein tyrosine phosphatases (PTPs) have been under-investigated. To date, six non-transmembrane PTPs (NTPTPs), PTP-1B, Shp1, Shp2, MEG2-PTP, LMW-PTP and HePTP and a single receptor-like PTP (RPTP), CD148, have been identified in platelets. The main objective of this thesis was to determine the functional role of CD148 in platelets, which had never been studied in platelets. Using a mouse model, I demonstrate that CD148 is a critical positive regulator of signalling from the main collagen activation receptor GPVI and the fibrinogen integrin $\alpha$II$\beta$3, and also plays a minor role in regulating thrombin and thromboxane A_\ (TxA$_2$ mediated aggregation and secretion via the PAR-4 and TP receptors, respectively. The molecular mechanism of how CD148 regulates signalling from so many receptors is by maintaining a pool of active Src family kinases (SFKs) in platelets, which it does by dephosphorylating a tyrosine residue in the C-terminal of all SFKs. In an attempt to identify other PTPs that perform a similar function to CD148 in platelets, I analyzed platelets from PTP-1B- and TC-PTP-deficient mouse models for functional and phosphorylation defects. PTP-1B-deficient platelets exhibited minor aggregation/secretion and phosphorylation defects relative to CD148-deficient platelets; and TC-PTP, which I show to be expressed in human and mouse platelets for the first time, is involved in platelet development. My conclusion is that CD148, PTP-1B and TC-PTP have distinct functional roles in platelets

CD148 : a positive regulator of GPVI and αIIbβ3 proximal signalling in platelets

Platelets are small anucleate blood cells that plug holes in damage blood vessels. They do so by adhering to exposed extracellular matrix proteins at sites of injury and aggregating together. Platelet responsiveness to injury is controlled by a diverse repertoire of surface receptors that can be divided into two broad categories based on how they signal; the tyrosine kinased-linked receptors and the G protein-coupled receptors (GPCRs). There has been much work on elucidating the functions of tyrosine kinases in platelets, whereas protein tyrosine phosphatases (PTPs) have been under-investigated. To date, six non-transmembrane PTPs (NTPTPs), PTP-1B, Shp1, Shp2, MEG2-PTP, LMW-PTP and HePTP and a single receptor-like PTP (RPTP), CD148, have been identified in platelets. The main objective of this thesis was to determine the functional role of CD148 in platelets, which had never been studied in platelets. Using a mouse model, I demonstrate that CD148 is a critical positive regulator of signalling from the main collagen activation receptor GPVI and the fibrinogen integrin αIIbβ3, and also plays a minor role in regulating thrombin and thromboxane A₂ (TxA₂) mediated aggregation and secretion via the PAR-4 and TP receptors, respectively. The molecular mechanism of how CD148 regulates signalling from so many receptors is by maintaining a pool of active Src family kinases (SFKs) in platelets, which it does by dephosphorylating a tyrosine residue in the C-terminal of all SFKs. In an attempt to identify other PTPs that perform a similar function to CD148 in platelets, I analyzed platelets from PTP-1B- and TC-PTP-deficient mouse models for functional and phosphorylation defects. PTP-1B-deficient platelets exhibited minor aggregation/secretion and phosphorylation defects relative to CD148-deficient platelets; and TC-PTP, which I show to be expressed in human and mouse platelets for the first time, is involved in platelet development. My conclusion is that CD148, PTP-1B and TC-PTP have distinct functional roles in platelets.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Artificial light and cloud cover interact to disrupt celestial migrations at night

The growth of human activity and infrastructure has led to an unprecedented rise in the use of Artificial Light at Night (ALAN) with demonstrable impacts on ecological communities and ecosystem services. However, there remains very little information on how ALAN interacts with or obscures light from celestial bodies, which provide vital orientating cues in a number of species. Furthermore, no studies to date have examined how climatic conditions such as cloud cover, known to influence the intensity of skyglow, interact with lunar irradiance and ALAN over the course of a lunar cycle to alter migratory abilities of species.Our night-time field study aimed to establish how lunar phase and climatic conditions (cloud cover) modulate the impact of ALAN on the abundance and migratory behaviour of Talitrus saltator, a key sandy beach detritivore which uses multiple light associated cues during nightly migrations. Our results showed that the number and size of individuals caught decreased significantly as ALAN intensity increased. Additionally, when exposed to ALAN more T. saltator were caught travelling parallel to the shoreline, indicating that the presence of ALAN is inhibiting their ability to navigate along their natural migration route, potentially impacting the distribution of the population. We found that lunar phase and cloud cover play a significant role in modifying the impact of ALAN, highlighting the importance of incorporating natural light cycles and climatic conditions when investigating ALAN impacts. Critically we demonstrate that light levels as low as 3 lux can have substantial effects on coastal invertebrate distributions. Our results provide the first evidence that ALAN impacted celestial migration can lead to changes to the distribution of a species. <br/

Is measurement uncertainty from sampling related to analyte concentration?

The contribution of sampling to the combined uncertainty of measurement is assessed using a combination of literature review and experimental determination of sampling variability in a range of foodstuffs in order to determine whether there is a consistent relationship between analyte level and proportion of variation attributable to sampling. Experimental determinations used the duplicate method, an economical method of assessing the relative contributions of sampling and analytical variability to the overall variance of results. The experimental work covered sampling of retail foodstuffs. 101 estimates of between-target, between-sampling, and within-sample variance were obtained. It is shown for the first time that sampling variance across the food sector appears to follow a Horwitz-like relationship sufficient to provide estimated between-sample standard deviation to within approximately an order of magnitude. The results from different methods of data processing for sampling uncertainty experiments are also compared. It is shown that for the data sets obtained experimentally in this study, log- transformation is of minor importance while the use of robust statistical methods can have greater but less predictable effects on estimated sampling variance

Association of RENAL nephrometry score with outcomes of minimally invasive partial nephrectomy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98294/1/iju3222.pd

Interacting galaxies in the IllustrisTNG simulations - I : Triggered star formation in a cosmological context

We use the IllustrisTNG cosmological hydrodynamical simulations to investigate how the specific star formation rates (sSFRs) of massive galaxies (M-* > 10(10) M-circle dot) depend on the distance to their closest companions. We estimate sSFR enhancements by comparing with control samples that are matched in redshift, stellar mass, local density, and isolation, and we restrict our analysis to pairs with stellar mass ratios of 0.1 to 10. At small separations (similar to 15 kpc), the mean sSFR is enhanced by a factor of 2.0 +/- 0.1 in the flagship (110.7Mpc)(3) simulation (TNG100-1). Statistically significant enhancements extend out to 3D separations of 280 kpc in the (302.6Mpc)(3) simulation (TNG300-1). We find similar trends in the EAGLE and Illustris simulations, although their sSFR enhancements are lower than those in TNG100-1 by about a factor of two. Enhancements in IllustrisTNG galaxies are seen throughout the redshift range explored (0Peer reviewe

Fusion of RVG or gh625 to Iduronate-2-Sulfatase for the Treatment of Mucopolysaccharidosis Type II

Mucopolysaccharidosis type II (MPSII) is a lysosomal storage disease caused by a mutation in the IDS gene, resulting in deficiency of the enzyme iduronate-2-sulfatase (IDS) causing heparan sulfate (HS) and dermatan sulfate (DS) accumulation in all cells. This leads to skeletal and cardiorespiratory disease with severe neurodegeneration in two thirds of sufferers. Enzyme replacement therapy is ineffective at treating neurological disease, as intravenously-delivered IDS is unable to cross the blood-brain barrier (BBB). Haematopoietic stem cell transplant is also unsuccessful, presumably due to insufficient IDS enzyme production from transplanted cells engrafting in the brain. We used two different peptide sequences (RVG and gh625), both previously published as BBB-crossing peptides, fused to IDS and delivered via haematopoietic stem cell gene therapy (HSCGT). HSCGT with LV.IDS.RVG and LV.IDS.gh625 was compared to LV.IDS.ApoEII and LV.IDS in MPSII mice at 6-months post-transplant. Levels of IDS enzyme activity in the brain and peripheral tissues were lower in LV.IDS.RVG and LV.IDS.gh625 treated mice than in LV.IDS.ApoEII and LV.IDS treated mice, despite comparable vector copy numbers. Microgliosis, astrocytosis and lysosomal swelling were partially normalised in MPSII mice treated with LV.IDS.RVG and LV.IDS.gh625. Skeletal thickening was normalised by both treatments to wild-type levels. Although reductions in skeletal abnormalities and neuropathology are encouraging, given the low levels of enzyme activity compared to control tissue from LV.IDS and LV.IDS.ApoEII transplanted mice, the RVG and gh625 peptides are unlikely to be ideal candidates for HSCGT in MPSII, and are inferior to the ApoEII peptide that we have previously demonstrated to be more effective at correcting MPSII disease than IDS alone

Marine artificial light at night:An empirical and technical guide

The increasing illumination of our world by artificial light at night (ALAN) has created a new field of global change research with impacts now being demonstrated across taxa, biological ranks and spatial scales. Following advances in terrestrial ecology, marine ALAN has become a rapidly growing research area attracting scientists from across all biomes. Technological limitations, complexities of researching many coastal and marine ecosystems and the interdisciplinary nature of ALAN research present numerous challenges. Drawing on expertise from optical oceanographers, modellers, community ecologists, experimental and molecular biologists, we share practical advice and solutions that have proven useful for marine ALAN research. Discussing lessons learnt early on can help in the effective and efficient development of a field. The guide follows a sensory ecology approach to marine light pollution and consolidates physics, ecology and biology. First, we introduce marine lightscapes highlighting how these differ from terrestrial ones and provide an overview of biological adaptations to them. Second, we discuss study design and technology to best quantify ALAN exposure of and impacts on marine and coastal organisms including molecular tools and approaches to scale-up marine ALAN research. We conclude that the growing field of marine ALAN research presents opportunities not only for improving our understanding of this globally widespread stressor, but also for advancing fundamental marine photobiology, chronobiology and night-time ecology. Interdisciplinary research will be essential to gain insights into natural marine lightscapes shaping the ecology and evolution coastal and marine ecosystems

The tyrosine phosphatase CD148 is an essential positive regulator of platelet activation and thrombosis

Platelets play a fundamental role in hemostasis and thrombosis. They are also involved in pathologic conditions resulting from blocked blood vessels, including myocardial infarction and ischemic stroke. Platelet adhesion, activation, and aggregation at sites of vascular injury are regulated by a diverse repertoire of tyrosine kinase–linked and G protein–coupled receptors. Src family kinases (SFKs) play a central role in initiating and propagating signaling from several platelet surface receptors; however, the underlying mechanism of how SFK activity is regulated in platelets remains unclear. CD148 is the only receptor-like protein tyrosine phosphatase identified in platelets to date. In the present study, we show that mutant mice lacking CD148 exhibited a bleeding tendency and defective arterial thrombosis. Basal SFK activity was found to be markedly reduced in CD148-deficient platelets, resulting in a global hyporesponsiveness to agonists that signal through SFKs, including collagen and fibrinogen. G protein–coupled receptor responses to thrombin and other agonists were also marginally reduced. These results highlight CD148 as a global regulator of platelet activation and a novel antithrombotic drug targe

Developing an intervention to facilitate family communication about inherited genetic conditions, and training genetic counsellors in its delivery.

Many families experience difficulty in talking about an inherited genetic condition that affects one or more of them. There have now been a number of studies identifying the issues in detail, however few have developed interventions to assist families. The SPRinG collaborative have used the UK Medical Research Council's guidance on Developing and Evaluating Complex Interventions, to work with families and genetic counsellors (GCs) to co-design a psycho-educational intervention to facilitate family communication and promote better coping and adaptation to living with an inherited genetic condition for parents and their children (<18 years). The intervention is modelled on multi-family discussion groups (MFDGs) used in psychiatric settings. The MFDG was developed and tested over three phases. First focus groups with parents, young people, children and health professionals discussed whether MFDG was acceptable and proposed a suitable design. Using evidence and focus group data, the intervention and a training manual were developed and three GCs were trained in its delivery. Finally, a prototype MFDG was led by a family therapist and co-facilitated by the three GCs. Data analysis showed that families attending the focus groups and intervention thought MFDG highly beneficial, and the pilot sessions had a significant impact on their family' functioning. We also demonstrated that it is possible to train GCs to deliver the MFDG intervention. Further studies are now required to test the feasibility of undertaking a definitive randomised controlled trial to evaluate its effectiveness in improving family outcomes before implementing into genetic counselling practice.The National Institute of Health Research funded the study but any views expressed do not necessarily reflect those of the Authority. Funded by NIHR reference number: RP-DG-1211-10015