| Abstract [eng] |
The Influence of the Substances Produced by Activated Neutrophils on the Migratory Activity of Mesenchymal Stem Cells Adult mesenchymal stem cells (MSCs) are multipotent stem cells which have the ability to differentiate into cells of multiple organs and systems such as bone, fat, cartilage, muscle, neurons, hepatocytes and insulin-producing cells. That is why they have generated a great deal of interest for their potential use in regenerative medicine and tissue engineering. MSCs are thought to be crucial for tissue regeneration, acting via migration into the site of injury, proliferating and differentiating into functional cells. The lesion of a tissue is always followed by the inflammatory reaction. It means that the MSCs migrate and access to the inflammatory environment. Neutrophil infiltration is a common pathological feature in acute inflammatory disorders. In the pathology sites they release oxygen species and their internal constituents, which are stored in different granules. The goal of this research work was to estimate the influence of the substances produced and released by activated neutrophils on the migratory activity of MSCs. The research work consisted of four groups of experiments. First of all we have determinated the level of the chemokinetic MSCs‘ migration and we have measured the chemotactic reponse to two different stimulus: DMEM suplemented with 10% FCS and 1% human plasma. That was an important stage for planning the further experiments. Secondly, we assessed whether the activated neutrophils‘ supernatant was able to act as a chemoattractant for the MSCs. We also suspended MSCs in the supernatant of neutrophils activated in two different manners (by fMLP and PMA) and we estimated the influence of substanced released during neutrophils‘ degranulation and the influence of the reactive oxygen species to the MSCs chemotaxis and chemokinesis. Chemotactic and chemokinetic responses were measured by a modified Boyden chamber assay using a 10-well chemotaxis chamber AA10 with polycarbonate filters with 8 mm pores. Evaluation of completed transmigration was performed on the stained filters under a light microscope at 20× magnification. The number of migrated cells in control and stimulated wells was counted for 5 random fields per well and the average of the transmigrated cells in each well was calculated. Results: we have determined that the supernatant of activated neutrophils was an effective inducer for chemotaxis of MCSs. The products of neutrophils degranulation released after their activation by fMLP partly arrested MSCs in the upper wells and significantly reduced their chemokinetic and chemotactic activity. Neutrophils‘ degranulation products and reactive oxygen species released after the activation of neutrophils by PMA also caused statistically significant reduction in MSCs chemokinetic and chemotactic activity. Conslusions: the substances produced by activated neutrophils are the chemotactic stimulus for the MSCs and they are able to modulate their migratory activity. These factors are released under inflammatory conditions and may contribute to the homing of MSCs as well as to their arresting in the pathology site where they accomplish their regenerative function. |
