Response kinetics of radiation-induced micronucleated reticulocytes in human bone marrow culture

• Published in: Mutation research. Genetic toxicology and environmental mutagenesis 2011-01, Vol.718 (1), p.38-43
• Main Authors: Sun, Hongliang, Tsai, Ying, Nowak, Irena, Dertinger, Stephen D., Wu, J.H. David, Chen, Yuhchyau
• Format: Article
• Language: English
• Subjects: 3D bone marrow culture; Biological and medical sciences; Bone marrow; Cell culture; DNA damage; Fundamental and applied biological sciences. Psychology; Genetics; Genetics of eukaryotes. Biological and molecular evolution; Genotoxicity; Kinetics; Medical sciences; Micronucleated reticulocytes; Micronuclei; Mutation; Radiation; Toxicology
• ISSN: 1383-5718; 1879-3592
• DOI: 10.1016/j.mrgentox.2010.10.007

▶ Radiation induced micronucleated reticulocytes (MN-RETs) represent radiation genotoxic effects on the bone marrow progenitor and precursor cells for erythropoiesis. The kinetics of MN-RET induction after radiation remains unknown and it requires total body irradiation to healthy humans, which is clearly not feasible. ▶ We describe a long-term human bone marrow culture system using 3D bioreactors that sustain terminal differentiation of erythropoiesis for several weeks. ▶ The kinetics of erythropoiesis in 3D human marrow culture was investigated in this report. ▶ The kinetics of radiation-induced MN-RET of human bone marrow was investigated. This is the first report of this kind in the literature. The data is made possible by experimentation of human bone marrow cultures established in 3D bioreactors that sustain terminal differentiation of red blood cells. ▶ The radiation dose–response of human MN-RET induction in the 3D bone marrow culture system was investigated and reported in this manuscript. The frequency of micronucleated reticulocytes (MN-RETs) in the bone marrow or peripheral blood is a sensitive indicator of cytogenetic damage. While the kinetics of MN-RET induction in rodent models following irradiation has been investigated and reported, information about MN-RET induction of human bone marrow after radiation exposure is sparse. In this report, we describe a human long-term bone marrow culture (LTBMC), established in three-dimensional (3D) bioreactors, which sustains long-term erythropoiesis. Using this system, we measured the kinetics of human bone marrow red blood cell (RBC) and reticulocyte (RET) production, as well as the kinetics of human MN-RET induction following radiation exposure up to 6 Gy. Human bone marrow established in the 3D bioreactor demonstrated an average percentage of RBCs among total viable cells peaking at 21% on day 21. The average percentage of RETs among total viable cells reached a maximum of 11% on day 14, and remained above 5% by day 28, suggesting that terminal erythroid differentiation was still active. Time- and dose-dependent induction of MN-RET by gamma radiation was observed in the human 3D LTBMC, with peak values occurring at approximately 3 days following 1 Gy irradiation. A trend towards delayed peak to 3–5 days post-radiation was observed with radiation doses ≥2 Gy. Our data reveal valuable information on the kinetics of radiation-induced MN-RET of human bone marrow cultured in the 3D bioreactor, a syntheti