Abstract
The concept of hormesis describes a phenomenon of adaptive response to low-dose ionizing radiation (LDIR). Similarly, the concept of mitohormesis states that the adaptive program in mitochondria is activated in response to minor stress effects. The mechanisms of hormesis effects are not clear, but it is assumed that they can be mediated by reactive oxygen species. Here, we studied effects of LDIR on mitochondria in mesenchymal stem cells. We have found that X-ray radiation at a dose of 10 cGy as well as oxidized fragments of cell-free DNA (cfDNA) at a concentration of 50 ng/mL resulted in an increased expression of a large number of genes regulating the function of the mitochondrial respiratory chain complexes in human mesenchymal stem cells (MSC). Several genes remained upregulated within hours after the exposure. Both X-ray radiation and oxidized cfDNA resulted in upregulation of FIS1 and MFN1 genes, which regulated fusion and fission of mitochondria, within 3–24 h after the exposure. Three hours after the exposure, the number of copies of mitochondrial DNA in cells had increased. These findings support the hypothesis that assumes oxidized cell-free DNA as a mediator of MSC response to low doses of radiation.
Highlights
The effects of low-dose ionizing radiation (
We have studied the expression of nuclear DNA genes NDUFA1, NDUFA4, NDUFA5, NDUFA10, NDUFB10, NDUFC2, NDUFS7, NDUFS2, NDUFV1, NDUFS1, NDUFA9, and ACAD9 as well as mitochondrial DNA genes ND6, ND5, and ND4L that control the synthesis of proteins, which are the part of the Complex I of the mitochondrial respiratory chain or regulate its function
The results demonstrate that both radiation at a dose of 10 cGy and cfDNAox causes an increase in the expression of nuclear DNA genes NDUFA1, NDUFA4, NDUFA5, NDUFA10, NDUFC2, NDUFS2, NDUFS1, and ACAD9 as well as mitochondrial DNA genes ND4L, ND2, and ND6 within 3 h after exposure
Summary
The effects of low-dose ionizing radiation (
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have