ERC FUNDED PROJECTS

Celiac disease affects at least 1% of the world population. Its onset is triggered by gluten, a common dietary protein, however, its etiology is poorly understood. More than 80% of patients are not properly diagnosed and they therefore do not follow a gluten-free diet, thereby increasing their risk for disease-associated complications and early death. A better understanding of the disease biology would improve the diagnosis, prevention, and treatment of celiac disease. This project investigates the disease mechanisms in celiac disease by using predisposing genes and genetic variants as disease initiating factors. Specifically, it will investigate if long, intergenic non-coding RNAs (lincRNAs) are causally involved in celiac disease pathogenesis by regulating protein-coding genes and pathways associated with the disease. This project is based on two important observations by my group: (1) Our genetic studies, which led to identifying 39 celiac disease risk loci, suggest that the mechanism underlying the disease is largely governed by dysregulation of gene expression. (2) We uncovered a previously unrecognized role for lincRNAs that provides clues as to exactly how genetic variation causes disease, as this class of biologically important RNA molecules regulate gene expression. The research will be performed in CD4+ T cells, a severely affected cell type in disease pathology. I will first use celiac disease-associated protein-coding genes to delineate their regulatory pathways and then study the transcriptional programs of lincRNAs present in celiac disease loci. Next I will combine the information and investigate if the expressed lincRNAs modulate the pathways and affect T cell function, thereby discovering if lincRNAs are a missing link between non-coding genetic variation and protein-coding genes. Our findings may well lead to potential therapeutic targets and provide a solid scientific basis for new diagnostic markers, particularly biomarkers, based on genetics.

2 319 914 €

Start date: 2013-02-01, End date: 2018-11-30

"Our cells receive tens of thousands of different DNA lesions per day. Failure to repair these lesions will lead to cell death, mutations and genome instability, which contribute to human diseases such as neurodegenerative disorders and cancer. Efficient recognition and repair of DNA damage, however, is complicated by the fact that genomic DNA is packaged, through histone and non-histone proteins, into a condensed structure called chromatin. The DNA repair machinery has to circumvent this barrier to gain access to the damaged DNA and repair the lesions. Our recent work suggests that chromatin-modifying enzymes (CME) help to overcome this barrier at sites of DNA damage. However, the identity of these CME, their mode of action and interconnections with DNA repair pathways remain largely enigmatic. The aim of this project is to systematically identify and characterize the CME that operate during DNA repair processes in both yeast and human cells. To reach this goal we will use a cross-disciplinary approach that combines novel and cutting-edge genomics approaches with bioinformatics, genetics, biochemistry and high-resolution microscopy. Epigenetics-IDentifier (Epi-ID) will be used as a tool to unveil novel CME, whereas RNAi-interference and genetic interaction mapping studies will pinpoint the CME that may potentially regulate repair of DNA damage. A series of functional assays will eventually characterize their role in distinct DNA repair pathways, focusing on those that counteract DNA strand breaks and replication stress. Together these studies will provide insight into how CME assist cells to repair DNA damage in chromatin and inform on the relevance of CME to maintain genome stability and counteract human diseases."

1 999 575 €

Start date: 2014-03-01, End date: 2019-02-28

The 3D organization of chromosomes within the nucleus is of great importance to control gene expression. The cohesin complex plays a key role in such higher-order chromosome organization by looping together regulatory elements in cis. How these often megabase-sized looped structures are formed is one of the main open questions in chromosome biology. Cohesin is a ring-shaped complex that can entrap DNA inside its lumen. However, cohesin’s default behaviour is that it only transiently entraps and then releases DNA. Our recent findings indicate that chromosomes are structured through the processive enlargement of chromatin loops, and that the duration with which cohesin embraces DNA determines the degree to which loops are enlarged. The goal of this proposal is two-fold. First, we plan to investigate the mechanism by which chromatin loops are formed, and secondly we wish to dissect how looped structures are maintained. We will use a multi-disciplinary approach that includes refined genetic screens in haploid human cells, chromosome conformation capture techniques, the tracing in vivo of cohesin on individual DNA molecules, and visualization of chromosome organization by super-resolution imaging. With unbiased genetic screens, we have identified chromatin regulators involved in the formation of chromosomal loops. We will investigate how they drive loop formation, and also whether cohesin’s own enzymatic activity plays a role in the enlargement of loops. We will study whether and how these factors control the movement of cohesin along individual DNA molecules, and whether chromatin loops pass through cohesin rings during their formation. Ultimately, we plan to couple cohesin’s linear trajectory along chromatin to the 3D consequences for chromosomal architecture. Together our experiments will provide vital insight into how cohesin structures chromosomes.

1 998 375 €

Start date: 2018-04-01, End date: 2023-03-31

The DNA within our cells is constantly being damaged by both environmental and endogenous agents; of the many forms of DNA damage, the DNA double-strand break (DSB) is considered to be most dangerous. Correct processing of DSBs is not only essential for maintaining genomic integrity but is also required in specific biological processes, such as meiotic recombination and V(D)J recombination, in which DNA breaks are deliberately generated. In animals, defects in the proper response to DSBs can thus have different outcomes: cancer predisposition, embryonic lethality, or compromised immunity. Many genes that play a role in the processing of DSBs have been identified over the past decades, mainly by cloning genes that are responsible for specific human genomic instability or immune deficiency syndromes, and by genetic approaches using unicellular eukaryotes and rodent cell lines. It is, however, evident that many components required in higher eukaryotes are not yet known and the identification of those will be a major challenge for future research. Here, we will for the first time systematically test all genes encoded by an animals genome directly for their involvement in the cellular response to DSB in both somatic and germline tissues: we will use our recently developed transgenic animal models (C. elegans) that visualizes repair of a single localized genomic DNA break in genome wide RNAi screenings to identify (and then characterize) the complement of genes that are required to keep our genome stable, and when mutated can predispose humans to cancer. In parallel, we will study the cellular response to single DNA breaks that are artificially generated during different stages of gametogenesis, as well as address the developmental consequences of DSB induction during the earliest stages of embryonic development – an almost completely unexplored area in the field of genome instability and DNA damage responses.

1 060 000 €

Start date: 2008-05-01, End date: 2014-04-30