Project R-2336

Therapeutic application of multipotent stem cells in an animal model of multiple sclerosis (Research)

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS), characterized by multifocal zones of inflammation, demyelination and neurodegeneration. To date, MS remains an incurable disease that to a limited extent can be slowed or stabilized. The current therapies are limited in having only immune modulatory effects. One of the major challenges in the MS research is the development of therapeutic products which also induce remyelinisation and/or neuroregeneration in addition to an anti-inflammatory effect. In the search for appropriate strategies the concept of stem cell transplantation or injection of myelin forming progenitor cells is promising. It has already been shown that neural stem cells derived from fetal or adult brain have therapeutic effects in EAE, the animal model for MS. The beneficial effects of these stem cells included both tissue repair and modulation of autoimmune processes. However, from a clinical point of view it is impossible to isolate neural stem cells from humans, since this would require dangerous invasive surgery. The aim of this research project is to determine the therapeutic potential of easily obtainable stem cells for use in MS. 2 types of stem cells are examined: stem cells from the umbilical cord (umbilical cord-derived stem cells: UCMS) and from the bone marrow (multipotent adult progenitor cells: MAPC). These cells already showed therapeutic effects in animal models for other (neuro) degenerative diseases such as Parkinsons disease spinal cord injury & stroke. In the first instance, human UCMS will be characterized and compared to the already known properties of MAPC. Here, the expression of relevant mesenchymal surface markers, embryonic markers and immunological molecules will be determined by means of immunocytochemistry and flow cytometry. Also, in the context of transplantation in MS, the expression of functional chemokine receptors and adhesion molecules will be examined. In addition, the differentiation capacity of UCMS towards neural progenitor cells using specially defined differentiation medium or co-culture with astrocytes is investigated (objective 1). Next, (pre-differentiated) UCMS and MAPC will be transplanted in a rat model of chronic EAE. The effect on clinical course, pathology and immune response will be examined, using immunohistochemical stains of brain, spinal cord and lymph nodes slices of EAE animals. The tissue will be specifically examined for the presence of stem cells, T cells and macrophages (objective 2). Furthermore, the possible mechanisms by which remyelinisation and/or immunomodulation are induced will be examined in vivo. To this end, stem cells are transplanted into a chronic rat EAE model and ethidium bromide demyelination model. Post-mortem tissue of brain, spinal cord and lymph nodes is investigated by means of flow cytometry and immunohistochemistry for the presence of differentiated stem cells and immune cells (objective 3). Finally, it is investigated whether genetic manipulation of UCMS and MAPC can increase their clinical potential. By means of electroporation genes coding for specific chemokine receptors and neurotrophic factors will be inserted in the stem cells. The effect of this manipulation will once again be tested in the chronic rat EAE model (objective 4).

01 January 2010 - 31 December 2013