Tumour cell expansion in bladder epithelium

Bladder cancer is common in western society. The major problem of patients with superficial bladder cancer is the high recurrence rate and multifocality of these tumours. In 70 % of the patients superficial bladder cancer recurs after local resection of the tumour within 15 years. The tumour recurrences are probably caused by tumour cells that were not removed by the therapy. These residual tumour cells apparently can form secondary tumours at multiple sites in the bladder mucosa. In this respect bladder cancer is different from other carcinomas. Factors involved in the normal physiology of the bladder epithelium may also attribute to the expansion of tumour cells and the recurrence of bladder carcinomas. In order to provide better understanding of the process of bladder cancer recurrence the anatomy and histology of the urinary bladder and the carcinogenesis of bladder carcinoma are described in paragraphs 1.1 and 1.2. In paragraph 1.3 the development of tumour recurrences is described and a hypothesis is developed regarding the role of extracellular matrix components, growth factors and adhesion molecules in the development of recurrences, either by affecting the normal bladder epithelium or by affecting the bladder carcinoma cells themselves (paragraph 1.4)

Modulation of intra-epithelial expansion of human T24 bladder-carcinoma cells in murine urothelium by growth factors and extracellular-matrix components

The high recurrence rate of bladder cancer is probably due to an efficient repopulation of the bladder by residual transformed cells after resection of the tumour. However, the regenerating capacity of the normal urothelial cells is very high. To study the balance between regenerating normal urothelium and outgrowth of transformed urothelial cells, we recently developed an in vitro co-cultivation model. With this model system we studied the effects of growth factors and extracellular-matrix components on the intra-epithelial expansion of human T24 bladder-carcinoma cells in primary mouse-bladder explants. Exposure of the cultures to acidic fibroblast growth factor (aFGF) and laminin led to a dramatic increase in the number of invasive T24 cells into the primary urothelium. Epidermal growth factor (EGF) and collagen types I and IV counteracted the infiltration of individual T24 cells. EGF, aFGF, laminin and collagen types I and IV did not directly affect the migration and proliferation of T24 cells. Apparently, the efficacy of invasion of transformed urothelial cells into primary urothelium is not only dependent on the intrinsic characteristics of the transformed cells, but can be influenced to a considerable extent by exogenous components exerting their influence on the normal urothelium. The clinical relevance of this observation needs to be studied further

An in vitro model of urothelial regeneration: Effects of growth factors and extracellular matrix proteins

Although the cellular turnover of resting urothelium is very low, its regenerative capacity is known to be outstanding. In organotypic mouse urothelial cultures closely mimicking the differentiation and multilayering of normal urothelium, we examined the cell biological mechanisms underlying urothelial regeneration and the specific role of growth factors and several extracellular matrix (ECM) components. Exposure to epidermal growth factor (EGF) and acidic fibroblast growth factor (aFGF) and culture on laminin resulted in enhanced expansion of the urothelium. Microscopy and assessment of proliferative activity revealed that enhanced urothelial expansion due to EGF could be attributed to increased proliferative activity and an increase in cell numbers, whereas aFGF-stimulated expansion must be considered the consequence of increased cellularity and migration. Laminin-enhanced urothelial expansion was shown to be the result of spreading of the entire urothelial organotypic culture. This was associated with a considerable decrease in the number of cell layers. A synergistic effect of growth factors and laminin was not found. This organotypic urothelial cell culture model seems to be very useful in studying strategies to improve urothelial regeneration

Ontwikkeling van een meetlat voor immuuncompetentie in varkens, vleeskuikens en vleeskalveren

Het doel van dit project is om een “meetlat” te ontwikkelen die de effecten van (voedings)interventies gericht op de verbetering van de immuuncompetentie van varkens, pluimvee en vleeskalveren kan vaststellen. Immuuncompetentie is binnen dit project gedefinieerd als het vermogen van dieren om effectieve responsen van het immuunsysteem te tonen op het moment dat de gezondheid van het dier onder druk wordt gezet. Een meetlat voor immuuncompetentie kan in de toekomst door de diervoedingssector gebruikt worden bij de ontwikkeling en evaluatie van nieuwe voerconcepten, ingrediënten en additieven gericht op de verbetering en ondersteuning van diergezondheid. Het is bekend dat de samenstelling van de voeding van jonge dieren invloed heeft op de functionele ontwikkeling van het maagdarmkanaal en op de samenstelling van de daarin aanwezige microbiota. De interacties tussen de microbiota en de weefsels van het darmkanaal (cross talk) hebben een belangrijke invloed op de ontwikkeling van immuuncompetentie. Daarom wordt in dit project gefocust op de effecten van (voedings)interventies op de microbiota, genexpressie veranderingen in darmweefsel, en morfologische en immunologische veranderen in de darm. De hier gepresenteerde meetlat voor immuuncompetentie is gebaseerd op de resultaten van onderzoek binnen het VDI programma van Feed4Foodure (projecten VDI-11; vleeskuikens, VDI-12; biggen, VDI- 13; gespeende biggen en kalveren) waarin m.b.v. model interventies de effecten van variatie in voersamenstelling op de microbiota samenstelling in het darmkanaal, de biologische responsen van darmweefsel en de zoötechnische dierprestaties zijn onderzocht. In de hier gepresenteerde meetlat worden gemeten effecten in deze studies aan elkaar gerelateerd en functioneel inzichtelijk gemaakt. Dit rapport beschrijft de ontwikkeling en totstandkoming van een eerste versie van de meetlat. Hierbij worden gemaakte keuzes, beperkingen en mogelijkheden van de meetlat bediscussieerd. Tenslotte wordt inzicht gegeven in de mogelijkheden tot verdere verfijningen en de toepasbaarheid van de meetlat

Healthy and resilient livestock

Individual animals react differently to similar challenges. Animals relatively unaffected by the challenge or quick to recover are resilient. We will bridge different expertise to unravel the underlying mechanism of resilient animals. Biomarkers and sensors will be used to investigate resilience. The aim will be to understand mechanisms causing variations in responses between individuals after a disturbance. How the balance between health and disease could be influenced. Resulting in resilient animals with a positive effect for animal and human health ‘One health’

Transcription profiling of chickens infected with Eimeria maxima or mock infected and then infected with E. maxima, E. acervulina or mock infected

Eimeria are obligate intracellular protozoan parasites which can affect chickens. After exposure to Eimeria chickens establish (partial) protective immunity to the homologues strain. In this paper we investigate the process responsible for Eimeria protection. In order to find host reactions specificly involved in protection to homologous re-infection we investigated the host reactions after primary infection and a homologous or heterologous secondary infection. Broilers were mock infected or infected with E.maxima (Max) at one week of age. Two weeks later broilers were mock infected, infected with E.maxima or E.acervulina. Oocyst output, T-cell population and cytokine mRNA expression profiles and Eimeria DNA profiles were measured 2, 4 and 7 days pi. Specific regulation of gene expression profiles was monitored by a whole genome oligo-array containing 20.673 oligoﾴs at 8 and 24 hours pi