Promotor: Prof.dr. G.P. van Wezel

This thesis consists of three chapters, the first two of which concern division points of elements of the multiplicative group of a number field.

The aim of this thesis is to study cell-cell interactions and the development of an assay to explore and quantify the exchange of membrane compounds.

Streptomyces present a valuable platform for natural product discovery. Lugdunomycin is a novel angucycline-derived polyketide from Streptomyces sp QL37, with unprecedented skeleton and antimicrobial activity.

Wiskunde en Natuurwetenschappen, Leiden Academic Centre for Drug Research (LACDR)

Latent variable modeling of students' solution strategies and performance

Despite being the object of intense study, embryonic development has been difficult to model due to a number of reasons. First, complex tissues can be comprised of many cell types, of which we probably only know a subset.

Mechanical interactions between cells and their environment play an important role in many biological processes.

Promotor: Prof.dr. J. Kuiper

Cardiovascular disease is a major global burden and atherosclerosis is the main underlying pathological process.

Promotor: Prof.dr. T. Schmidt

Epithelial-mesenchymal plasticity (EMP) and tumor cell migration play an important role in cancer progression, and an improved understanding of the mechanisms underlying these concepts is essential for developing new targeted approaches.

A new type of tripodal squaramide-based supramolecular hydrogels is developed and studied.

During embryonic growth, cells proliferate, differentiate, and collectively migrate to form different tissues at the right position and time in the body.

Almost all bacteria are enveloped by a cell wall that provides cellular protection.

Traditional drug discovery approaches have been hampered by (in vitro) cell-culture models that poorly represent the situation in the human body.

Aspergillus niger is an important industrial producer of organic acids and enzymes producing large amounts of spent fungal biomass.

In this research project, we aimed to obtain more insight in the role of mast cells in the immune driven disorders rheumatoid arthritis and atherosclerosis.

There is an urgent need for more physiologically relevant cell culture methods to guide compound selection in pre-clinical stages of the drug development pipeline.

This thesis focuses on two processes involved in fighting infections: metabolism and immune cell motility and navigation.

This thesis describes the design and synthesis of fragments of various cell wall carbohydrates of the Streptococcus species, including the branched Group B-specific antigen (GBC) of Group B Streptococcus, glycerol phosphate (GroP) modified group A carbohydrate (GAC), and the O-acetylated type 1 capsular…

Mechanical forces are known to play an important role in bacterial colonies. In this dissertation, we study the self-organization at various stages of growing bacterial colonies, and focus on the mechanical effects of cell growth.

CONCLUSION: This study demonstrates that human macrophages can be induced to exert direct anti-tumor activity against osteosarcoma cells. Our observation that the induction of macrophage anti-tumor activity by L-MTP-PE required IFN-gamma may be of relevance for the optimization of L-MTP-PE therapy in…

In order to gain a better insight into the basis of the rapid jasmonic acid (JA)-mediated stress response, an integrated approach using a targeted high-resolution mass spectrometry-based (HRMS) platform, was conducted to monitor the metabolism of JA using the model system of cell suspension cultures…

This thesis describes the functional analysis of the Arabidopsis AHL15 gene.

Bacteria have the ability to alter their morphology in order to adapt to changing environments.

Promotores: Prof.dr. G.F.A. Kersten, W. Jiskoot, Co-promotor: J-P. Amorij

Synthetic hydrogels that mimic the natural extracellular matrix in the biophysical and biochemical cues it provides to cells are in high demand, however the cell phenotypes as they are observed in vivo in numerous cases have yet to be attained.

Streptomyces are multicellular, Gram-positive bacteria in the phylum of actinobacteria which produce a high amount of bioactive natural products of which the expression is tightly coordinated with the life cycle.

Cytotoxic T-cells (CTLs) are involved in the clearance of viruses and killing of tumor cells.

Promotor: C.A.J. Knibbe, Co-promotor: J.J. Boelens, R.G.M. Bredius

Promotores: H. Schiessel, G.T. Barkema

Supervisor: P.J.J. Hooykaas

Promotor: Prof.dr. R. Verpoorte, Co-Promotores: N.R. Mustafa, A.E. Schulte

Light-Harvesting Complex II (LHCII) is responsible for light absorption and excitation energy transfer in plants and photosynthetic algae, while in high light it undergoes conformational changes by which it quenches excitations to prevent photodamage.

The deeper understanding of an organism's pathology is important for developing treatments. Over centuries of systematic research, clinical researchers have demonstrated that the more information they acquire about the cellular properties and their organisation in the tissue, the better they can understand…

This thesis describes the antimicrobial discovery strategy developed in our group, the den Hertog Group at the Hubrecht Institute. It includes a cultivation-based screening approach for novel antimicrobial agents from the source of fungi, and a bacterial time-lapse imaging approach for antimicrobial…

Promotor: A.H. Meijer, Co-promotor: B.E. Snaar-Jagalska

The way organisms develop from the initial single-cellular state to a complex final assembly like the human body, and how the final body is maintained throughout life, is one of the greatest mysteries and it’s understanding one of the biggest scientific challenges.

In this thesis, the focus lies on studying glucocorticoid receptor dynamics in living cells with the aim of understanding how this transcription factor finds its DNA target sites to regulate transcription.

Promotie

Promotor: G.A. van der Marel, Co-promotor: J.D.C. Codée

This dissertation contains four works during my PhD. Different biomaterials have been designed based on coiled-coil peptides. These biomaterials have a range of applications, inclusing drug delivery, cell sorting to cell-cell fusion.

The main aim of this thesis was to unravel the signaling and regulatory networks that drive tumor cell migration during breast cancer metastasis.

Details kunnen zien van een zieke of gezonde cel, dat is mogelijk met de supermicroscoop van het consortium Cyttron. Niet alleen de microscoop is vernieuwend in zijn soort: ook de vorm waarop de partijen samenwerken past in de huidige tijd. “Toegang tot elkaars techniek, daar draait het om in ons samenwerkingsverband”,…

Met de nodige maatregelen starten onderzoekers hun werkzaamheden in verschillende laboratoria weer deels op. Het Leidse Cell Observatory is één van de plekken waar wetenschappers sinds 11 mei hun labwerk hervatten.

Streptomyces are filamentous bacteria that produce more than two-thirds of known antibiotics.

This thesis describes our search to identify and understand possible regulatory mechanisms of integrin α6β4 in cell-matrix adhesion and intracelular signaling.