Medical countermeasures under the NRBC risk are still insufficient. Indeed, exposure to ionizing radiation can have serious consequences for the health of exposed people and potentially impact many victims. In humans, doses greater than ˜ 6 Gy over a large volume mainly induce bone marrow destruction (HS hematopoietic syndrome) and digestive injury, resulting in rapid death by gastrointestinal syndrome (GIS). Medical management of SH is complex but possible by stimulating residual hematopoiesis through growth factors administration or, if necessary, bone marrow transplantation. On the other hand, the management of the GIS remains confronted with a therapeutic wall and no scientific consensus on a therapeutic solution for the management of the GIS exists today. The preclinical studies described to treat GIS have all been based on mono-therapeutic approaches. The INTRUST project proposes a paradigm shift and a different conceptual approach based on the assumption that only a global and multimodal approach could be truly effective, robust and accessible to a significant number of victims. There is a strong rationale for proposing therapeutic strategies for GIS management based in part on pathophysiological features common to inflammatory bowel disease (IBD) and radiation-induced intestinal injury. Indeed, these two diseases share identical symptoms (abdominal pain, frequent diarrhea, bleeding) associated with inflammation of the digestive tract and intestinal epithelium destruction. The contemporary clinical view of IBD is moving towards global or multimodal approaches that could be applied to GIS. Thus we identify 4 essential components to consider for an effective therapeutic strategy: 1) act quickly after irradiation to physically protect the intestinal mucosa, 2) combine therapeutic agents regenerating the digestive mucosa, 3) control intestinal inflammation by immuno-modulators and finally 4) manage the septic/microbiota parameter The project aims to put in place innovative medical countermeasures for the management of radiological exposure inducing acute intestinal failure. Specifically, the project aims to demonstrate the interest and feasibility of a multimodal therapeutic approach by targeting the first 3 components. Thus we propose 1) to develop innovative biomaterials compatible with regenerative and emergency medicine that can quickly adhere and protect the digestive mucosa (muco-adhesive bio-gels) and find solutions for intestinal delivery. In parallel, innovative biomaterials will also be developed to set up and optimize a tool "mini-organs 3D in vitro" or " human intestinal organoids " to select molecules able to regenerate the intestinal mucosa. Finally 2) we propose to test in vivo multimodal treatment combining muco-adhesive biomaterial administration, selected epithelial regenerating molecules and immuno-modulators that have demonstrated a significant efficacy in IBD. The therapeutic efficacy of this multimodal treatment will be tested on preclinical models of GIS and IBD. The project benefits from a multidisciplinary consortium that has acquired preliminary results essential to the project’s feasibility. The INTRUST project has a very strong dual military and civilian character because the potential benefits are both for soldiers in operations or civil suffering from GIS and for patients suffering from IBD whose incidence continues to increase in young people or digestive toxicity after radiotherapy for the treatment of cancer.

Intracellular cholesterol trafficking is essential for the maintenance of vascular integrity. However, the mechanisms by which cholesterol is transported into the cell are poorly understood. Recently, we showed that a ligand of Wnt signaling, Wnt5a, inhibits intracellular cholesterol accumulation in vascular smooth muscle cells (VSMCs). We show that Wnt5a interacts with lysosomal Niemann-Pick C1/C2 proteins and cholesterol, facilitates its export from the lysosome and protects against atherosclerosis. We also generated antibodies that activate Wnt signaling. We show that these antibodies decrease cholesterol accumulation in VSMCs. The aim of the present project is 1) to study the physiological mechanisms by which Wnt5a facilitates intracellular cholesterol trafficking and interacts with NPCs, 2) to test the therapeutic potential in atherosclerosis of the antibodies we generated and that activate Wnt signaling. 3) In a pilot study, we assayed several Wnt ligands in the sera of 86 patients with familial hypercholesterolemia (FH) and 32 controls. Our results show a marked and significant negative correlation of several of these ligands with the presence of coronary lesions, suggesting that they can be used as biomarkers during atherosclerosis. In a larger study, these markers will be evaluated by Elisa in sera of HF patients from the Rhu Chopin (CHOlesterol Personalized Innovation) registry. This national registry aims to identify new markers of cardiovascular risk. In addition, by sequencing our candidate Wnt genes in FH probands without mutations in the LDLR/APOB/PCSK9/APOE genes, a genetic study will establish the spectrum of variants of these Wnt genes in these patients.

Fibrosis is defined as an excessive accumulation of extracellular matrix (ECM) components such as certain collagens, and is the leading cause of morbidity and mortality in chronic diseases. Major efforts have focused on preventing ECM synthesis, but these have been unsuccessful and conceptually unsuitable for the clinical situation where fibrosis is usually detected at an advanced stage of the disease, when organs already display advanced fibrotic lesions. The NanoKFT project proposes to change the paradigm of fibrosis treatment by focusing on ECM degradation instead of on ECM synthesis in the context of chronic kidney disease. Interstitial collagen accumulation depends on the balance between synthesis and proteolytic degradation. A partially uncoiled conformation of the collagen fiber is necessary for proteases to have an optimal physical access to their cleavage site. Increasing the temperature is a way to promote uncoiling of collagen fibers, thereby facilitating their degradation. This can be achieved by using the properties of nanoparticles capable of releasing thermal energy upon exposure to alternating high frequency magnetic fields. In NanoKFT, we propose a highly innovative, non-invasive anti-fibrotic strategy using targeted nanotherapy. We aim to generate moderate and non-lethal hyperthermia in the fibrotic kidney ex-vivo (WP1) and in vivo (WP2) using functionalized iron oxide nanoparticles (IONPs) designed to specifically target interstitial collagen fibers. The hypothesis is that localized hyperthermia will cause collagen fibers to uncoil, thereby promoting the accessibility of endogenous proteases to their cleavage site and thus the degradation of interstitial collagen. To carry out this ambitious interdisciplinary project, NanoKFT brings together experts in renal fibrosis and targeted nanotherapy.

The goal of the SuperMagStemCells project is to produce cardiac-primed engineered tissues, starting from magnetic stem cells, and using remote magnets for tissue formation and stimulation. To do so, it must resolve the impact that magnetic nanoparticles may have on stem cells functions, especially at high intracellular magnetic dose, probably linked to the intracellular release of degradation products. Our main hypothesis is that shielding the magnetic core from degradation will prevent any biological impact on stem cells. We will provide non-degrading magnetic nanoparticles by designing nanohybrids featuring a magnetic core protected by a continuous gold shell. A specific attention will be paid to the optimization of the magnetic properties of the core, to generate in fine ultra-magnetic@gold nanohybrids. A parallel approach will be explored to escape toxicity through an unprecedented biosynthesis route we have just reported in stem cells. The final goal will be to deliver (super)magnetic and functional stem cells. In this context, the three objectives of SuperMagStemCells are: (1) to develop (ultra)magnetic nanohybrids (magnetic@gold) that would be totally protected from the harsh intracellular environment; (2) to fully understand all potential long-term risks in iron oxide long-term intracellular degradation, and to explore a biosynthetic approach to make the stem cells produce their own, inherently biocompatible, magnetic nanoparticles; and (3) to produce and test in vivo magnetically-organized and stimulated stem-cells-based tissue substitutes for cardiac tissue regeneration.

Marfan syndrome (MFS) is a connective tissue disorder associated with autosomal dominant inheritance. MFS is caused by mutations in the FBN1 gene (15q21), responsible for fibrillin-1 protein deficiency or dysfunction. MFS is a multisystem disorder with manifestations in the skeletal, cardiovascular, pulmonary, and ocular systems and in skin, and dura. Cardiovascular disorders and more specifically aortic dissections are the most life-threatening clinical manifestations of MFS, mostly preceded by aortic root dilation occurring in approximately 80% of the MFS patients. Therapeutic options for MFS aortopathy are limited including ß-blockers and type 1 angiotensin receptors antagonists whose effectiveness is not optimal. Replacement of the ascending aorta is the most important manner to prevent aortic dissection and rupture but surgery remains associated with morbidity, mortality and need for re-operation. Therefore, more efforts have to be deployed towards the development of therapeutic approaches targeting pathophysiological pathways involved in MFS aortopathy progression and complications. The pathophysiology of MFS is complex combining fibrillin deficiency, elastin layer degradation, smooth muscle cell dysfunction and death. There are accumulating evidence that immune-inflammatory responses are locally impaired in MFS patients with the accumulation of vascular tissue macrophages and local release of pro-inflammatory cytokines and chemokines. Based on promising preliminary results in murine models of MFS, we hypothesized that TREM-2 a receptor expressed by vascular macrophages orchestrates local inflammatory responses and protects against both aortic aneurysm progression and complications. In this ambitious project combining experiments in murine models and analysis of human samples, we aim to explore the role of TREM-2 in the pathophysiology of MFS and to test a therapeutic approach using agonistic anti-TREM-2 antibody. We will use different mouse models to assess the effects of global TREM-2 deficiency or specific TREM-2 deficiency in macrophage subsets (monocyte-derived or resident) on aortic pathology. We will study the consequences of TREM-2 deficiency on matrix remodeling, the local inflammatory response and ultimately on aortic dilatation and its complications. Therapeutic approaches using monoclonal antibodies to stimulate TREM-2 will be evaluated at early and late stages of the pathology in a murine model of Marfan syndrome. Finally, the clinical relevance of our data will be assessed on human aortic tissue from Marfan patients.