The German National Cohort (GNC) is a joint interdisciplinary endeavour of scientists from the Helmholtz and the Leibniz Association, universities, and other research institutes. Its aim is to investigate the causes for the development of major chronic diseases, i.e. cardiovascular diseases, cancer, diabetes, neurodegenerative/-psychiatric diseases, musculoskeletal diseases, respiratory and infectious diseases, and their pre-clinical stages or functional health impairments. Across Germany, a random sample of the general population will be drawn by 18 regional study centres, including a total of 100,000 women and 100,000 men aged 20–69 years. The baseline assessments include an extensive interview and self-completion questionnaires, a wide range of medical examinations and the collection of various biomaterials. In a random subgroup of 20 % of the participants (n = 40,000) an intensified examination (“Level 2”) programme will be performed. In addition, in five of the 18 study centres a total of 30,000 study participants will take part in a magnetic resonance imaging examination programme, and all of these participants will also be offered the intensified Level 2 examinations. After 4–5 years, all participants will be invited for a re-assessment. Information about chronic disease endpoints will be collected through a combination of active follow-up (including questionnaires every 2–3 years) and record linkages. The GNC is planned for an overall duration of 25–30 years. It will provide a major, central resource for population-based epidemiology in Germany, and will help to identify new and tailored strategies for early detection, prediction, and primary prevention of major diseases.

Molecular patterning processes taking place in biological systems are challenging to study in vivo because of their dynamic behavior, subcellular size, and high degree of complexity. In vitro patterning of biomolecules using nanolithography allows simplification of the processes and detailed study of the dynamic interactions. Parallel dip-pen nanolithography (DPN) is uniquely capable of integrating functional biomolecules on subcellular length scales due to its constructive nature, high resolution, and high throughput. Phospholipids are particularly well suited as inks for DPN since a variety of different functional lipids can be readily patterned in parallel. Here DPN is used to spatially pattern multicomponent micro- and nanostructured supported lipid membranes and multilayers that are fluid and contain various amounts of biotin and/or nitrilotriacetic acid functional groups. The patterns are characterized by fluorescence microscopy and photoemission electron microscopy. Selective adsorption of functionalized or recombinant proteins based on streptavidin or histidine-tag coupling enables the semisynthetic fabrication of model peripheral membrane bound proteins. The biomimetic membrane patterns formed in this way are then used as substrates for cell culture, as demonstrated by the selective adhesion and activation of T-cells.

Differential gene expression through alternative premRNA splicing is crucial to various physiological and pathological conditions. Upon activation of B and T lymphocytes during an immune response, variant isoforms of the cell surface molecule CD44 are generated by alternative pre-mRNA splicing. We show here that in primary mouse T cells as well as in the murine LB-17 T-cell line upregulation of variant CD44 mRNA species upon T-cell activation requires activation of the MEK±ERK pathway. By employing mutant signaling molecules and a novel luciferasebased splice reporter system we demonstrate that the Ras±Raf±MEK±ERK signaling cascade, but not the p38 MAP-kinase pathway, activates a mechanism that retains variant CD44 exon v5 sequence in mature mRNA. The ®ndings demonstrate that a highly conserved pleiotropic signaling pathway links extracellular cues to splice regulation, providing an avenue for tissue-speci®c, developmental or pathology-associated splicing decisions.

High‐molecular‐weight splice variants of the CD44 transmembrane protein family have been implicated in tumorigenesis and metastasis formation. By contrast, in certain tumors‐for example, Burkitt's lymphoma, neuroblastomas, and prostate cancer‐loss of CD44 expression seems to accompany transformation. Here we describe two modes of action of CD44 proteins. They can bind growth factors and present them to their authentic high‐affinity receptors, and thus promote proliferation and invasiveness of cells. Under these conditions the CD44 proteins recruit ERM proteins‐for example, ezrin or moesin‐to their cytoplasmic tails, thereby producing links to the cytoskeleton. This mode of action could account for the tumor‐promoting action of CD44 proteins. The second mode of action of CD44 proteins comes into play when cells reach confluent growth conditions. Under specific conditions, binding of another ligand, the ECM component hyaluronate, leads to the activation and binding to the CD44 cytoplasmic tail of the tumor suppressor protein merlin. The activation of merlin confers growth arrest, so‐called contact inhibition. This function of CD44 proteins defines them as tumor suppressors. The type of action of CD44 on a given cell will depend on the isoform pattern of CD44 expressed, on the cellular equipment with ERM protein members, on the nature of the ECM, and on yet‐unknown conditions.

Regulation of alternative pre-mRNA splicing, recognized as increasingly important in causing human disease, was studied using the CD44 gene, whose splice variants have been implicated in tumor progression. We identified heterogeneous ribonucleoprotein (hnRNP) A1 as a protein interacting in vitro and in vivo with regulatory splice elements in CD44 variant exon v5. Transient overexpression of hnRNP A1 prevented v5 exon inclusion, dependent on the exonic elements. HnRNP A1-dependent repression was exon-specific and could be relieved by coexpression of oncogenic forms of Ras and Cdc42. The results define hnRNP A1 as a decisive part of an oncogene-regulated splice-silencing complex, which can select between multiple alternatively spliced exons.Alternative pre-mRNA splicing, an important mechanism of differential gene expression in higher eukaryotes, gives rise to functionally distinct proteins encoded by a single gene. The generation of alternatively spliced mRNAs can be regulated, e.g. according to the developmental or physiological state of cells in an organism (for recent reviews see Refs. 1 and 2). Pre-mRNA splicing is accomplished by large ribonucleoprotein complexes called spliceosomes, which are assembled on pre-mRNA, directed by small conserved sequences localized at the intron ends, the splice sites (3). Several alternatively spliced pre-mRNAs have been shown to contain regulatory sequences, in addition to the splice sites, that can affect splice site selection dependent on developmental cues. Such sequences have been found in exons and introns, both in Drosophila and mammalian pre-mRNAs (reviewed in Refs. 2-4). In Drosophila, sex-specific splice regulators have been cloned by genetic approaches (4 -6). In contrast, in mammalian cells, factors that govern alternative splicing during differentiation processes or in pathological conditions are largely unknown. Likewise, the mechanisms underlying the regulated generation of complex splice patterns due to selection between multiple alternatively spliced exons, a hallmark of many genes encoding highly variable proteins, are still elusive. Selection of splice sites in mammalian cells has been studied primarily by biochemical means. Two groups of proteins have been found that can affect splice site choice: serine/arginine-rich (SR) 1 proteins (for reviews on SR proteins and splicing, see Refs. 7-10) and heterogeneous nuclear ribonucleoproteins (hnRNPs) (for reviews, see Refs. 11-13).Splice site selection plays an important role in human diseases (14 -18), and alternative splicing of several genes has been implicated in tumorigenesis and tumor progression (15, 19 and references therein). The best known example of these genes encodes the cell surface molecule CD44 (for reviews on CD44 splicing and cancer, see Refs. 20 and 21). Alternative pre-mRNA splicing generates variant CD44 isoforms by the inclusion of up to 10 variant exons (v1-v10) during embryonic development, upon activation of lymphocytes (22-25) and of dendritic cells (26) and during tumor progression (20,...