Extracellular mutant mitochondrial DNA content is sharply elevated in the blood plasma of irradiated mice
Abdullaev, S.A.; Antipova, V.N.; Gaziev, A.I.
Molekuliarnaia Biologiia 43(6): 1063-1069
2009
ISSN/ISBN: 0026-8984 PMID: 20088383 Document Number: 633214
Nucleic acids circulating in blood plasma and other biological fluids may be of interest as potential markers for diagnosis of various pathologies and monitoring of stress influences. For many genotoxic agents, mitochondrial DNA (mtDNA) is a more vulnerable target than nuclear DNA, and mutations of mitochondrial genome may be markers of many diseases. In the present study extracellular mtDNA with mutations was determined in the blood plasma of mice exposed to X-radiation at a dose of 5 Gy. Mutations were assessed from cleavage by CEL-endonuclease (mismatch specific cleavage enzyme) of heteroduplexes obtained by hybridization of mtDNA PCR amplikons (gene ND3 and D-loop region) from the blood plasma of irradiated and control mice. The total number of copies of mtDNA (gene ND4) against nuclear DNA (gene GAPDH) was measured by the Real-Time PCR method. A content of mtDNA with mutations in the blood plasma of mice was elevated during one month of the post-radiation period, however, the levels were not the same at different time periods (1, 4, 8, 14, 28 days), the highest one being detected on the 14 day after irradiation. The increased content of extracellular mutant mtDNA in blood plasma of X-irradiated mice can be considered as a sensitive biomarker for assessing radiation injury and effects of other genotoxic agents.