ERC FUNDED PROJECTS

The interaction of cells with the extracellular matrix or neighboring cells plays a crucial role in many cellular functions, such as motility, differentiation and controlled cell death. Expanding on pioneering studies on defined 2-D model systems, the role of the currently known determinants (geometry, topography, biochemical functionality and mechanical properties) is currently addressed in more relevant 3-D matrices. However, there is a clear lack in currently available approaches to fabricate well defined microenvironments, which are asymmetric or in which these factors can be varied independently. The central objective of ASMIDIAS is the development of a novel route to asymmetric microenvironments for cell-matrix interaction studies. Inspired by molecular self-assembly on the one hand and guided macroscale assembly on the other hand, directed assembly of highly defined microfabricated building blocks will be exploited to this end. In this modular design approach different building blocks position themselves during assembly on pre-structured surfaces to afford enclosed volumes that are restricted by the walls of the blocks. The project relies on two central elements. For the guided assembly, the balance of attractive and repulsive interactions between the building blocks (and its dependence on the object dimensions) and the structured surface shall be controlled by appropriate surface chemistry and suitable guiding structures. To afford the required functionality, new approaches to (i) topographically structure, (ii) biochemically functionalize and pattern selected sides of the microscale building blocks and (iii) to control their surface elastic properties via surface-attached polymers and hydrogels, will be developed.The resulting unique asymmetric environments will facilitate novel insight into cell-matrix interactions, which possess considerable relevance in the areas of tissue engineering, cell (de)differentiation, bacteria-surface interactions and beyond.

1 484 100 €

Start date: 2011-11-01, End date: 2016-10-31

Cardiovascular disease keeps the top spot in mortality statistics in Europe with 2 million deaths annually and although prevention and therapy have continuously been improved, the prevalence of heart failure continues to rise. While contractile (systolic) dysfunction is readily accessible to pharmacological treatment, there is a lack of therapeutic options for reduced ventricular filling (diastolic dysfunction). The diastolic properties of the heart are largely determined by the giant sarcomeric protein titin, which is alternatively spliced to adjust the elastic properties of the cardiomyocyte. We have recently identified a titin splice factor that plays a parallel role in cardiac disease and postnatal development. It targets a subset of genes that concertedly affect biomechanics, electrical activity, and signal transduction and suggests alternative splicing as a novel therapeutic target in heart disease. Here we will build on the titin splice factor to identify regulatory principles and cofactors that adjust cardiac isoform expression. In a complementary approach we will investigate titin mRNA binding proteins to provide a comprehensive analysis of factors governing titin’s differential splicing in cardiac development, health, and disease. Based on its distinctive role in ventricular filling we will evaluate titin splicing as a therapeutic target in diastolic heart failure and use a titin based reporter assay to identify small molecules to interfere with titin isoform expression. Finally, we will evaluate the effects of altered alternative splicing on diastolic dysfunction in vivo utilizing the splice deficient mutant and our available animal models for diastolic dysfunction. The overall scientific goal of the proposed work is to investigate the regulation of cardiac alternative splicing in development and disease and to evaluate if splice directed therapy can be used to improve diastolic function and specifically the elastic properties of the heart.

1 499 191 €

Start date: 2012-01-01, End date: 2017-06-30

We want to use selective laser melting to pattern a substrate with different solid micro particles at a density of 1 million spots per cm2. First, a homogeneous particle layer is deposited on a substrate and a pattern of micro spots of melted matrix is generated by laser radiation. Then, non-melted particles are blown away. Embedded within the particles are different chemically reactive amino acid derivatives that will start coupling to very small synthesis sites upon melting the particle pattern in an oven. This is done once all of the 20 different amino acid particles have been glued by laser patterning to the surface. Washing away uncoupled material, removing Fmoc protecting group, and repeating the patterning steps according to standard Merrifield synthesis, leads to the combinatorial synthesis of very high-density peptide arrays. The main objective of this proposal is to develop this method up to the level of a semi-automated synthesis machine. In addition, we will use the manufactured very high-density peptide arrays to readout the information that is deposited in the immune system, i.e. find a peptide binder for every one of the 200-500 antibody species that patrol the serum of an individual in elevated levels. These experiments might lead to novel tools to find out the causes of hitherto enigmatic diseases because then we might be able to correlate antibody patterns with disease status without knowing in advance the disease-specific antibodies. Beyond the life sciences, we want to embed 10.000 peptides per cm2 within an insulating layer of alkane thiols, each on a different gold pad of a specially designed screening chip. Then, we could readout I/V characteristics of individual peptide species, and eventually find peptide-based diodes. These could be modified in their sequence and screened again for better performance. This evolution-inspired screening approach might lead to novel materials that could be used in fuel cells.

1 494 600 €

Start date: 2011-11-01, End date: 2016-10-31

The requirements on the eukaryotic cytoskeleton are not only of high complexity, but include demands that are actually contradictory in the first place: While the dynamic character of cytoskeletal structures is essential for the motility of cells, their ability for morphological reorganisations and cell division, the structural integrity of cells relies on the stability of cytoskeletal structures. From a biophysical point of view, this dynamic structure formation and stabilization stems from a self-organisation process that is tightly controlled by the simultaneous and competing function of a plethora of actin binding proteins (ABPs). To understand the self-organisation phenomena observed in the cytoskeleton it is therefore indispensable to first shed light on the functional role of ABPs and their underlying molecular mechanisms. Hereby development of reliable reconstituted model systems as has been proven by the great progress achieved in our understanding of individual crosslinking proteins that turn the cytoskeleton into a viscoelastic physical gel. The advantage of such reconstituted systems is that the biological complexity is decreased to an accessible level that the physical principles can be explored and identified. It is the aim of the present proposal to successively increase the complexity in a well defined manner to further progress in understanding the functional units of a cell. On the way to a sound physical understanding of cellular self organizing principles, the planned major step comprises the incorporation of active processes like the active (de-)polymerisation of filaments and motor mediated active reorganisation and contraction. We plan to develop new tools and approaches to address how the different kinds of ABPs are interacting with each other and how the structure, dynamics and function of the cytoskeleton is locally governed by the competition and interplay between them.

1 495 196 €

Start date: 2011-10-01, End date: 2012-03-31