The cellular components of the satellite cell niche participate in the regulation of skeletal muscle regeneration. Beside myogenic cells at different developmental stages, this niche is formed by cells of the immune system, the interstitial connective tissue and the vascular system. Unambiguous determination of the origin of these cell types could contribute to optimization of the cell-based therapy of skeletal muscle disorders. In our work, we intravenously transplanted mouse GFP+ unseparated bone marrow cells into whole-body lethally irradiated immunocompetent mice four weeks before cardiotoxin-induced injury of the recipients' skeletal muscles. Seven and 28 days after the toxin injection, the injured regenerating and contralateral intact muscles were examined for identification of GFP+ bone marrow-derived cells by direct fluorescence, protein immunohistochemistry and immunogold transmission electron microscopy. In both the intact and injured muscles, GFP positivity was determined in immune cells, mainly in macrophages, and in interstitial spindleshaped cells. Moreover, in the injured muscles, rare GFP+ endothelial cells of the blood vessels and newly formed myotubes and muscle fibres were present. Our results confirmed the ability of bone marrowderived cells to contribute to the cellular component of the satellite cell niche in the intact and regenerating skeletal muscle. These cells originated not only from haematopoietic stem cells, but obviously also from other stem or progenitor cells residing in the bone marrow, such as multipotent mesenchymal stromal cells and endothelial progenitors.
- MeSH
- buňky kostní dřeně cytologie MeSH
- fluorescence MeSH
- kosterní svaly zranění patologie ultrastruktura MeSH
- myši inbrední C57BL MeSH
- nika kmenových buněk * MeSH
- regenerace fyziologie MeSH
- satelitní buňky kosterního svalu cytologie MeSH
- zelené fluorescenční proteiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lymphocytes are among the most radiosensitive cells. After exposure of the organism to ionizing radiation, they promptly die by apoptosis at a rate proportional to the dose received. Because of this, they are frequently used in biodosimetry. We demonstrated that one hour after whole-body irradiation of rats, histone H2AX in the lymphocyte nuclei was quickly phosphorylated on serine 139, the phosphorylation process being directly dependent on the gamma radiation dose. In the work presented here, we studied the kinetics of lymphocyte depletion in the peripheral blood and phosphorylation of histone H2AX in the peripheral blood lymphocytes after local (thoracic) irradiation of rats. Twenty-four hours after whole-body irradiation of the rats at a dose of 5 Gy, the lymphocyte count declined to almost zero values, whereas after local irradiation of the thorax area, the counts of lymphocytes in the peripheral blood remained unaltered. The authors employed two methods (flow-cytometric and microscopic) for the gammaH2AX determination in the peripheral blood lymphocytes, 1 h after thoracic irradiation of rats. Flow cytometry revealed a dose dependence on the increase in gammaH2AX in a dose range of 10-30 Gy. The microscopic method was more sensitive in the case of lower radiation doses, the dependence on the dose being obvious from a dose as low as 5 Gy. The methods are able, in the dose range 5-30 Gy, to differentiate between the type of irradiation, i.e. the whole-body or local.
- MeSH
- apoptóza účinky léků účinky záření MeSH
- buněčné jádro účinky záření MeSH
- celotělové ozáření škodlivé účinky MeSH
- financování organizované MeSH
- fosforylace účinky záření MeSH
- histony účinky záření MeSH
- hrudník cytologie účinky záření MeSH
- imunochemie metody MeSH
- leukocyty mononukleární účinky záření MeSH
- lymfocyty účinky léků účinky záření MeSH
- potkani Wistar MeSH
- průtoková cytometrie využití MeSH
- radiometrie využití MeSH
- statistika jako téma MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
