ERC FUNDED PROJECTS

Angiogenesis research has focused on the sprouting of new capillaries. The mechanisms of vessel maturation are much less well understood. Yet, the maintenance of a mature, quiescent, and organotypically-differentiated layer of endothelial cells (ECs) lining the inside of all blood vessels is vital for human health. The goal of ANGIOMATURE is to identify, validate, and implement novel mechanisms of vascular maturation and organotypic EC differentiation that are active during development, maintenance of vascular stability in adults, and undergo changes in aging. We recently identified previously unrecognized gene expression signatures of vascular maturation in a genome-wide screen of ECs isolated from newborn and adult mice. Epigenetic mechanisms were identified that control the EC transcriptome through gain and loss of DNA methylation as well as EC differentiation and signaling specification. These findings pave the way for groundbreaking novel opportunities to study vascular maturation. By characterizing functionally diverse types of blood vessels, including continuous ECs in lung and brain and sinusoidal ECs in liver and bone marrow, the ANGIOMATURE project will (1) determine up to single cell resolution the transcriptional and epigenetic program(s) of vascular maturation and organotypic differentiation during adolescence, (2) analyze the functional consequences of such program(s) in differentiated ECs and their adaptation to challenge, and (3) study changes of maturation and differentiation program(s) and vascular responses during aging. We will towards this end employ an interdisciplinary matrix of approaches involving omics, systems biology, conditional gene targeting, organoid cell culture, and experimental pathology to create a high-resolution structural and functional organotypic angioarchitectural map. The project will thereby yield transformative mechanistic insights into vital biological processes that are most important for human health and healthy aging.

2 338 918 €

Start date: 2018-08-01, End date: 2023-07-31

The heart is one of the first and most complex organs formed during human embryogenesis. While its anatomy and physiology have been extensively studied over centuries, the normal development of human heart and dysregulation in disease still remain poorly understood at the molecular/cellular level. Stem cell technologies hold promise for modelling development, analysing disease mechanisms, and developing potential therapies. By combining multidisciplinary approaches centred on human induced pluripotent stem cells (hiPSCs), BIOCARD aims at decoding the cellular and molecular principles of human cardiogenesis and developing advanced inter-chimeric human-pig models of cardiac development and disease. State-of-the-art genetic modification techniques and functional genomics will be used to establish a molecular atlas of cell type intermediates of human cardiogenesis in vitro and unravel how their proliferation, differentiation and lineage choice are regulated in health and disease. This in vitro approach will be complemented by detailed analyses of how distinct hiPSC-derived cardiac progenitor populations commit and contribute to specific cardiac compartments in interspecies chimeric hearts in vivo. Finally, we will capitalize on the novel concept that combinations of different well-defined hiPSC-derived cardiac progenitor pools with timely-matched, native extracellular matrix from embryonic hearts will accomplish for the first time the realization of human heart organoids as 3D culture systems of developing heart structures. Clearly, BIOCARD will open game-changing opportunities for devising novel biomedical applications, such as human heart chamber-specific disease modelling, large-scale drug testing in appropriate human 3D cardiac bio-mimics, and regenerative cell therapies based on functional ventricular-muscle patches and direct cell conversion in vivo.

2 285 625 €

Start date: 2018-09-01, End date: 2023-08-31

Sphingolipids including ceramides are building blocks of cell membranes, but also act as regulated intracellular messenger molecules. Emerging data indicate that sphingolipids are dynamically regulated by nutrients, and in turn control systemic metabolism, for example, by modulating insulin secretion, proliferation and cell death of pancreatic beta cells. Dysfunction and death of beta cells are key events during the development of diabetes, from which more than 400 million patients suffer worldwide. While pharmacological inhibition of general ceramide biosynthesis is protective against diabetes in animal studies, side effects of total loss of ceramides prevent medical implementation. The de novo synthesis of ceramides is fully dependent on six ceramide synthase enzymes (CerS 1-6), which are expressed in a tissue specific manner, and generate ceramides with different chain lengths. Currently, the functional roles and regulatory modulators of each CerS are unknown in pancreatic beta cells. Importantly, the downstream mechanisms by which ceramides impair beta cell function and eventually cause diabetes are not defined. Here, I propose to combine genomics, proteomics and lipidomics to assess the function of ceramide synthases expressed in mouse and human beta cells. Furthermore, both the subcellular localisation and the post-translational modifications of CerS will be determined. The ceramide-interacting proteins mediating the deleterious effects of ceramides will be identified by lipid-protein crosslinking and functionally tested. Finally, in a translational approach, we will test the ability of recently generated novel specific CerS inhibitors with improved specificity to ameliorate beta cell stress, and improve insulin secretion in mouse and human beta cells. In sum, we will identify, characterize, validate and target ceramide synthases involved in beta cell biology and development of diabetes.

1 492 314 €

Start date: 2018-01-01, End date: 2022-12-31

Targeted therapy (TT) is frequently used to treat metastatic cancer. Although TT can achieve effective tumor control for several months, durable treatment responses are rare, due to emergence of aggressive, drug-resistant clones (RCs) with high metastatic competence. Tumor heterogeneity and plasticity result in multifaceted resistance mechanisms and targeting RCs poses a daunting challenge. To better understand the clinical emergence of RCs, my work focuses on the poorly understood events during TT-induced tumor regression. We recently reported that during this phase drug-responsive cancer cells release a therapy-induced secretome, which remodels the tumor microenvironment (TME) and propagates disease relapse by promoting the survival of drug-sensitive cells and stimulating the outgrowth of RCs. Consequently, intervening with combination therapies during the tumor regression period has the potential to prevent the clinical emergence of RCs in the first place. Here, we outline strategies to (1) understand how RCs emerge and (2) to leverage our findings on the TME remodeling for combination therapies. First, we will develop a novel and innovative parental clone-lookup method, that will allow us to identify and isolate treatment-naïve, parental clones (PCs) that gave rise to RCs. In functional experiments, we will assess (i) whether PCs were already resistant before or developed resistance during TT, (ii) whether PCs have a higher susceptibility to develop resistance than random clones, and (iii) the mechanistic basis for metastatic competence in different clones. Second, we will study the TT-induced TME remodeling, focusing on the effects on tumor vasculature and immune cells. We will utilize our results to target PCs and RCs by combining TT in the phase of tumor regression with other therapies, such as immunotherapies. Our study will provide new mechanistic insights into the biological processes during tumor regression and aims for novel therapeutic strategies.

1 500 000 €

Start date: 2018-03-01, End date: 2023-02-28