ERC FUNDED PROJECTS

Tissue homeostasis requires coordinated barrier function in blood and lymphatic vessels. Opening of junctions between endothelial cells (ECs) lining blood vessels leads to tissue fluid accumulation that is drained by lymphatic vessels. A pathological increase in blood vessel permeability or lack or malfunction of lymphatic vessels leads to edema and associated defects in macromolecule and immune cell clearance. Unbalanced barrier function between blood and lymphatic vessels contributes to neurodegeneration, chronic inflammation, and cardiovascular disease. In this proposal, we seek to gain mechanistic understanding into coordination of barrier function between blood and lymphatic vessels, how this process is altered in disease models and how it can be manipulated for therapeutic purposes. We will focus on two critical barriers with diametrically opposing functions, the blood-brain barrier (BBB) and the lymphatic capillary barrier (LCB). ECs of the BBB form very tight junctions that restrict paracellular access to the brain. In contrast, open junctions of the LCB ensure uptake of extravasated fluid, macromolecules and immune cells, as well as lipid in the gut. We have identified novel effectors of BBB and LCB junctions and will determine their role in adult homeostasis and in disease models. Mouse genetic gain and loss of function approaches in combination with histological, ultrastructural, functional and molecular analysis will determine mechanisms underlying formation of tissue specific EC barriers. Deliverables include in vivo validated targets that could be used for i) opening the BBB on demand for drug delivery into the brain, and ii) to lower plasma lipid uptake via interfering with the LCB, with implications for prevention of obesity, cardiovascular disease and inflammation. These pioneering studies promise to open up new opportunities for research and treatment of neurovascular and cardiovascular disease.

2 499 969 €

Start date: 2019-07-01, End date: 2024-06-30

Introduction: The ability of a cancer cell to invade into the surrounding tissue is the main feature of malignant cancer progression. Diffuse Intrinsic Pontine Glioma (DIPG) is a paediatric high-grade brain tumour with no chance of survival due to its highly invasive nature. Goal: By combining state-of-the-art imaging and transcriptomics, we aim to identify and target the key mechanisms driving the highly invasive growth of DIPG. Technology advances: Two unique single cell resolution imaging techniques that we have recently developed will be implemented: Large-scale Single-cell Resolution 3D imaging (LSR-3D) that allows visualization of complete tumour specimens and intravital microscopy using a cranial imaging window that allows imaging of tumour cell behaviour in living mice. In addition, we will apply a technique of live imaging Patch-seq to perform behaviour studies together with single cell RNA profiling. Expected results: Using a glioma murine model in which the disease is induced in neonates and a new embryonic model based on in utero electroporation, we expect to gain knowledge on the progression of DIPG in maturing brain. LSR-3D imaging on human and murine specimens will provide insight into the cellular tumour composition and its integration in the neuroglial network. With intravital imaging, we will characterize invasive cancer cell behaviour and functional connections with healthy brain cells. In combination with Patch-seq, we will identify transcriptional program(s) specific to invasive behaviour. Altogether, we expect to identify novel key players in cancer invasion and assess their potential to prevent DIPG progression.  Future perspective: With the studies proposed, we will gain fundamental insights into the cancer cell invasion mechanisms that govern DIPG which may provide new potential therapeutic target(s) for this dismal disease. Overall, the knowledge and advanced technologies obtained here will be of great value for the tumour biology field.

1 500 000 €

Start date: 2019-01-01, End date: 2023-12-31

In recent years, genome-wide association studies (GWAS) have discovered hundreds of single nucleotide polymorphisms (SNPs) which are significantly associated with coronary artery disease (CAD). However, the SNPs identified by GWAS explain typically only small portion of the trait heritability and vast majority of variants do not have known biological roles. This is explained by variants lying within noncoding regions such as in cell type specific enhancers and additionally ‘the lead SNP’ identified in GWAS may not be the ‘the causal SNP’ but only linked with a trait associated SNP. Therefore, a major priority for understanding disease mechanisms is to understand at the molecular level the function of each CAD loci. In this study we aim to bring the functional characterization of SNPs associated with CAD risk to date by focusing our search for causal SNPs to enhancers of disease relevant cell types, namely endothelial cells, macrophages and smooth muscle cells of the vessel wall, hepatocytes and adipocytes. By combination of massively parallel enhancer activity measurements, collection of novel eQTL data throughout cell types under disease relevant stimuli, identification of the target genes in physical interaction with the candidate enhancers and establishment of correlative relationships between enhancer activity and gene expression we hope to identify causal enhancer variants and link them with target genes to obtain a more complete picture of the gene regulatory events driving disease progression and the genetic basis of CAD. Linking these findings with our deep phenotypic data for cardiovascular risk factors, gene expression and metabolomics has the potential to improve risk prediction, biomarker identification and treatment selection in clinical practice. Ultimately, this research strives for fundamental discoveries and breakthrough that advance our knowledge of CAD and provides pioneering steps towards taking the growing array of GWAS for translatable results.

1 498 647 €

Start date: 2019-01-01, End date: 2023-12-31

Obesity is a metabolic disorder leading to various health risks and reduced life expectancy. Insulin resistance is a major obesity related disorder, and a main cause for the onset of type 2 diabetes. During cold exposure or caloric restriction (CR), brown adipocytes emerge within the white fat (known as “beige” cells). This process, referred to as fat browning, increases the metabolic capacity of the adipose tissues to combust energy and is seen as promising anti-obesity and anti-diabetic strategy. The intestinal microbiota co-develops with the host; microbiota depletion, or cold-induced shift of its composition are sufficient to improve insulin sensitivity and glucose metabolism, in part mediated by the innate immune system-mediated fat browning. The microbial signals and composition, critical for our understanding of the microbiota-host mutualism and metabolic improvements during cold and CR, remain unclear. By integrating expertise from several areas including physiology, bioinformatics, immunology, microbiology and developmental biology; and by developing computational approaches for comparing the metagenomics, metabolomics and transcriptomics data from the CR- and the cold-exposed mice with cohorts of human subjects, we will establish the microbiota role in orchestrating the CR-induced metabolic improvements and innate immune response, and provide mechanistic explanations on the microbiota-host mutualism during CR and cold. Finally, by using lineage-tracing studies and developing transgenic mouse models, we will determine the importance of the beige fat in the CR-induced beneficial effects on the host, and the importance of the microbiota in mediating this process. Manipulating the gut microbiota and exploiting the mechanistic links revealed by this study would be of conceptual importance for our understanding of microbiota-host mutualism in the metabolic homeostasis, and could lead to development of novel therapeutics for improving metabolic health.

1 999 999 €

Start date: 2019-06-01, End date: 2024-05-31