Tissue Eng Regen Med.  2017 Aug;14(4):421-432. 10.1007/s13770-017-0045-2.

Low-Dose Ionizing γ-Radiation Promotes Proliferation of Human Mesenchymal Stem Cells and Maintains Their Stem Cell Characteristics

• Cho W
• Kim ES
• Kang CM
• Ji YH
• Kim JI
• Park SJ
• Son Y
• Kim CH

• KMID: 2394976
• DOI: http://doi.org/10.1007/s13770-017-0045-2

Abstract

Mesenchymal stem cells (MSCs), which are multipotent and have self-renewal ability, support the regeneration of damaged normal tissue. A number of external stimuli promote migration of MSCs into peripheral blood and support their participation inwound healing. In an attempt to harness the potential beneficial effects of such external stimuli, we exposed human MSCs (hMSCs) to one such stimulus-low-dose ionizing radiation (LDIR)-and examined their biological properties. To this end, we evaluated differences in proliferation, cell cycle, DNA damage, expression of surface markers (CD29, CD34, CD90, and CD105), and differentiation potential ofhMSCs before and after irradiation with γ-rays generated using a ¹³â· CSirradiator.At doses less than 50 mGy, LDIR had no significant effect on the viability or apoptosis of hMSCs. Interestingly, 10 mGyofLDIR increased hMSC viability by 8% (p<0.001) comparedwith non-irradiatedhMSCs.At doses less than 50 mGy, LDIR did not induceDNA damage, including DNA strand breaks, or cause cellular senescence or cell-cycle arrest. Surface marker expression and in vitro differentiation potential of hMSCs were maintained after two exposures to LDIR at 10 mGy per dose. In conclusion, a two-dose exposure to LDIR at 10 mGy per dose not only facilitates proliferation of hMSCs, it alsomaintains the stem cell characteristics of hMSCswithout affecting their viability.These results provide evidence for the potential ofLDIRas an external stimulus for in vitro expansion of hMSCs and application in tissue engineering and regenerative medicine.

Keyword

Low dose ionizing radiation; Human mesenchymal stem cells; Proliferation; DNA damages; Differentiation

MeSH Terms

Apoptosis
Cell Aging
Cell Proliferation
DNA
DNA Damage
Humans*
In Vitro Techniques
Mesenchymal Stromal Cells*
Radiation, Ionizing
Regeneration
Regenerative Medicine
Stem Cells*
Tissue Engineering
DNA