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

Diatoms are major contributors of primary production in the ocean and participate in carbon sequestration over geologically relevant timescales. As key components of the Earth’s carbon cycle and marine food webs we need to understand the eco-evolutionary underpinnings of their ecological success to forecast their fate in a future ocean impacted by anthropogenic change. Genomes and epigenomes from model diatoms, as well as hundreds of transcriptomes from multiple species, have revealed genetic and epigenetic processes regulating gene expression in response to changing environments. The Tara Oceans survey has in parallel generated resources to explore diatom abundance, diversity and gene expression in the world’s ocean in widely contrasting conditions. DIATOMIC will build on these resources to understand how evolutionary and ecological processes combine to influence diatom adaptations to their environment at unprecedented spatiotemporal scales. To examine these processes over timescales relevant to current climate change, DIATOMIC includes the pioneering exploration of ancient diatom DNA from the sub-seafloor to reveal the genetic and epigenetic bases of speciation and adaptation that have impacted their ecological success during the last 100,000 years, when Earth experienced major climatological events and an increase in anthropogenic impacts. As a model for exploring eco-evolutionary processes in the past and contemporary ocean we will focus primarily on Chaetoceros because this diatom genus is ancient, ubiquitous, abundant and contributes significantly to carbon export. Key findings will be additionally supported by lab-based studies using the diatom Phaeodactylum for which exemplar molecular tools exist. Specifically, the project will address: 1. What molecular features characterize genome evolution in diatoms? 2. Which processes determine diatom metapopulation structure? 3. What can ancient DNA tell us about diatom adaptations to environmental change in the past?

2 495 753 €

Start date: 2019-11-01, End date: 2024-10-31

The overall aim of the IMMUNOTHROMBOSIS project is to clarify the mechanisms underlying the recently identified synergism between thrombosis and inflammation. Thrombus formation and inflammation are vital host responses that ensure homeostasis, but can also drive cardiovascular disease, including myocardial infarction and stroke, the major causes of death in Europe. My group and others discovered, that thrombosis and inflammation are not to be considered separate processes. They are tightly interrelated and synergize in immune defence, but also in inflammatory and thrombotic diseases in a process we termed immunothrombosis. Targeting this synergism has great potential to identify innovative and unconventional strategies to more specifically prevent undesired activation of thrombotic and inflammatory pathways. However, this requires a deeper mechanistic understanding of immunothrombosis. I recently identified two ground-breaking novel immunothrombotic principles: I discovered that platelets have the ability to migrate autonomously, which assists immune cells in fighting pathogens. Further, I revealed that immune cells play a central role in controlling the production of platelets from their megakaryocyte precursors. The physiological and pathophysiological relevance of both processes is unclear. This is the starting point and focus of the IMMUNOTHROMBOSIS project. My aim is to define how platelets use their ability to migrate to support immune cells in protection of vascular integrity (objective 1) and to identify the contribution of platelet migration to different cardiovascular diseases involving immunothrombotic tissue damage (objective 2). Finally, I will clarify how inflammatory responses feedback to the production of thrombotic effectors and dissect inflammatory mechanisms that control platelet production (objective 3). IMMUNOTHROMBOSIS will identify new options for specific prevention or treatment of thrombotic and inflammatory cardiovascular diseases.

2 321 416 €

Start date: 2019-09-01, End date: 2024-08-31

Research over the last few decades has revealed that animal life span is malleable and regulated by conserved metabolic signaling pathways, including reduced insulin/IGF signaling, mTOR, mitochondrial function, dietary restriction, and signals from the reproductive system. Whether these various pathways converge on common processes, however, has remained elusive. We recently discovered the nucleolus to be a crucial focal point of regulation in all these pathways. The nucleolus is a subnuclear organelle dedicated to rRNA production and ribogenesis, but also controls assembly of other ribonucleoprotein complexes including spliceosomes, signal recognition particle, small RNA processing, stress granules, and responds to growth and stress signaling. Remarkably we found that small nucleoli are a cellular hallmark of longevity in diverse species, and a correlate of metabolic health in humans. At the molecular level, long-lived animals show reduced levels of the nucleolar ribosomal RNA methylase, fibrillarin (FIB-1), and knockdown of C. elegans FIB-1 reduces nucleolar size, extends life span, and enhances innate immunity. Conversely, knockout of NCL-1/TRIM2 expands nucleolar size, suppresses life extension of major longevity pathways, and renders animals pathogen sensitive, revealing key regulators of nucleolargenesis, immunity and longevity. Here I propose to (Aim 1) clarify the mechanism of action of NCL-1, FIB-1 and interacting molecules (2) perform novel genetic screens for nucleolargenesis in C. elegans (3) uncover global transcriptomic and proteomic changes induced by NCL-1 and FIB-1 and survey several candidate nucleolar processes in regulating longevity and immunity (4) probe NCL-1/TRIM2 regulation of longevity in the short-lived killifish, Notobranchius furzeri, and develop nucleolar biomarkers of metabolic health in humans. These groundbreaking studies should illuminate how conserved signaling pathways work through the nucleolus to regulate health and life span.

2 500 000 €

Start date: 2020-01-01, End date: 2024-12-31