Stem cells are pluripotent (capable to differentiate into any type of tissue, and adult, which are responsible for a renewal of the particular tissue (hematopoietic neural, intestinal etc.). Recent research has shown that a border between these stem cells makes the expression of just few transcription factors. Stem cell needs an external stimulation to manifest its genetic information. This supplies external microenvironment that communicates with stem cells.
The basic component of extracellular matrix is a niche composed of several stromal accessory cells. These cells are in direct cell-to-cell communication with a stem cell, and they secrete cytokines influencing stem cell behaviour. Stem cell needs also other soluble signals including metabolic compounds, oxygen and other gas tension, adhesion to extracellular matrix proteins, as well as neural stimulation.
Our project is based on adult hematopoietic stem cells. These stem cells are used for stem cell transplantations to patients with hematopoietic disorders. The transplanted stem cells should find bone marrow (homing), migrate to available niches (seeding), and start to produce differentiated blood cells (engraftment).
We want to focus mainly to analysis of niche availability for transplanted normal and leukaemic haematopoietic stem/progenitor cells. This can be biased by regeneration of damaged haematopoietic tissue of the host caused by conditioning. We want also to compare murine bone marrow (medullar) and spleen (extramedullar) niches in terms of support, cell composition, and particularly significance of SDF-1 (CXCL12) cytokine interaction with its receptor CXCR4 for homing and engraftment of transplanted hematopoietic stem cells.
More info at http://biocev.lf1.cuni.cz