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The Role of Eicosanoids in the Cardiovascular Actions of Inhaled Nanoparticles

Nanoparticles (NPs) are minute pieces of material to which we are exposed every day in the air we breathe. Some are naturally occurring and have no impact on health, whereas others are produced from urban air pollution and can worsen diseases, particularly in the lungs and blood vessels. However, there is great interest in developing new NPs because of their unique properties that are useful for many applications, such as engineering, electronics and for drug delivery. At present it is unclear exactly what effects inhaled NPs have. Our current programme of research is designed to assess whether a specialized group of fats made in the body (called eicosanoids) drive the cardiovascular effects of NPs. The changes in the profiles of these fats will provide unique fingerprints that could be used to predict the actions of new NPs. In the proposed clinical study we shall investigate the effects of both environmental and manufactured carbonaceous NPs on the lungs, blood vessels, blood clotting, and levels of eicosanoids in blood and urine. We have previously investigated the cardiovascular effects of carbon nanoparticles after inhalation in man, and these experiments will investigate how the shape, size and composition of carbon particles influence these responses. These experiments will provide new insight into how NPs affect the body and pave the way for new ways to predict the toxic effects of NPs (reducing the need for animal experiments). The findings will enable the design of novel NP without the harmful characteristics of those found in air pollution.

Start: October 2018
Assessing Deformable Image Registration in the Lung Using Hyperpolarized-gas MRI

Recently, the investigators have demonstrated a novel hyperpolarized helium tagging Magnetic Resonance Image (MRI) technique that is capable of directly, in vivo, and non-invasively measuring physiological lung deformation on a regional basis. This unique imaging technique holds great promise for assessing, validating, and improving the use of Deformable image Registration (DIR) algorithms in the lung. Our long term aim is to apply hyperpolarized gas tagging MRI to study lung biomechanics, develop more physiologically sound DIR algorithms for the lungs, and eventually improve radiotherapy of lung cancer. The overall aim of this application is to optimize the hyperpolarized helium tagging MRI technology and establish its usefulness for DIR assessment. Our first objective is to develop and optimize a methodology based on 3 Dimensional (3D) hyperpolarized helium tagging MRI of healthy subjects, for directly measuring lung deformation between inhalation and exhalation. Our second objective is to develop physiologically sound digital thorax phantoms based on helium-3 tagging MRI of healthy subjects and demonstrate their use for DIR assessment in the lung. These phantoms will be used to evaluate a range different DIR algorithms, by comparing the errors between the DIR-derived deformation vector fields and the ground truth represented in the digital phantom. Successful completion of these aims will yield a novel methodology for DIR assessment in the lung for radiotherapy.

Start: July 2016
GROSS-HIST : Quantification of the Main Circulating Histones During Normal Pregnancy and Pregnancies With Placenta-mediated Complications

Pregnancy generates an increased thrombotic risk, and placental-mediated diseases are a risk factor for cardiovascular diseases, in particular: pre-eclampsia (PE), intrauterine growth retardation (IUGR), retroplacental hematomas (HRP), late intrauterine fetal deaths (LIFD) of placental origin and preterm deliveries of vascular origin. They are responsible for significant maternal-fetal morbidity/mortality. Data published in 2007 by the Haute Autorité de Santé (HAS) show that hypertension and pre-eclampsia are, in France, at the origin of 3 to 8% of the risk of perinatal mortality. During pregnancy, a transitional organ of foetal origin, the placenta, is established, which is essential for the maintenance and harmonious development of the pregnancy. The chorionic villus, in contact with maternal blood in the intervilleous chamber, is the structural and functional unit of the placenta. After the initial implantation phase, the trophoblastic cell constituting the main part of the placental villi differs in two ways: (A) into "citrus cytotrophoblasts" whose cells will fuse to generate the multinucleated outer layer giving the syncytiotrophoblast that ensures fetal-maternal exchanges and endocrine functions of the placenta; (B) into "invasive extra-city cytotrophoblasts" essential for the effective anchoring of the placenta in the decidualized uterine mucosa and for the remodelling of the terminal uterine spiral arteries, whose resistance to blood flow must collapse to allow effective oxygenation of the villi. Extra-city trophoblasts change from an epithelial phenotype to an endothelial phenotype. They may thus be exposed to pro-thrombotic factors such as endothelial cells. A lack of trophoblastic invasion and incomplete remodelling of the spiral uterine arteries are responsible for placental hypo-perfusion, hypoxia and the occurrence of placenta-mediated pathologies (pre-eclampsia, intrauterine growth retardation, retroplacental hematoma, fetal loss and fetal death in utero). The most common placental-mediated disease is pre-eclampsia (5% of births). It corresponds to a complication occurring from the second trimester of pregnancy and which is clinically characterized by high blood pressure, oedema and proteinuria. It is responsible for premature deliveries and is a major cause of intrauterine growth restriction. To date, there is no specific and early biomarker for the occurrence of placental vascular pathologies. Recent developments raise, for example, the question of circulating angiogenesis inhibitory factors (sFlt1, sEng) in pre-eclampsia. With regard to treatment, early administration of low-dose aspirin before 16 weeks of pregnancy seems to reduce the risk of pre-eclampsia, hence the importance of having very early markers of the disease. Discovering such markers is therefore one of the major challenges in strengthening women's follow-up and avoiding subsequent complications. For fetal losses and retroplacental hematoma, the administration of low molecular weight heparin has been shown to be effective. However, these treatments are not specific to placental vascular pathologies. Thus, understanding and exploring the cellular and molecular mechanisms of vascular-placental interface dysfunctions remains necessary to enable targeted management of patients feeding the general principle of precision medicine. Compare the concentrations of (i) circulating histones involved in inflammation, proliferation, migration or cell differentiation (H3-citrullinated histone, acetylated histones (Pan-histones), H1 histone) and (ii) free HMGB1 protein between the three patient groups ("GrossN", "GrossC", "VolS"). The histones H3-citrullinated, acetylated histones (Pan-histones), H1 histone as well as the free HMGB1 protein will be quantified. This choice corresponds to the histones involved in inflammation, proliferation, migration or cell differentiation and can be quantified to date.

Start: March 2019