Involvement of Wnt signaling in the injury of murine mesenchymal stem cells exposed to X-radiation.
OBJECTIVE
To investigate the injury of murine mesenchymal stem cells (mMSC) exposed to 4 Gy X-radiation and the role of canonical and non-canonical wingless-type (Wnt) signaling in the radiation injury.


METHODS
C3H10T1/2 cells were submitted to 4 Gy X-radiation. At different time points after radiation, Hoechst33258 staining and Annexin V-fluorescein isothiocyanate (FITC) flow cytometry analysis were performed to assess cellular apoptosis. Senescence-associated β-galactosidase (SA-β-gal) staining was performed to analyze cellular senescence. Cell cycle was measured by flow cytometry. P53, p21, Wnt3a, Wnt5a, sonic hedgehog (Shh) mRNA was detected by Real time polymerase chain reaction (PCR) and Wnt5a protein was determined by Western blot.


RESULTS
A time-dependent cellular apoptosis was observed with a peak level 12 hours after radiation. Cellular senescence was detected 72 h after radiation. A remarkable up-regulation of Wnt5a mRNA expression (∼ 269-fold) and protein expression was seen 72 h after radiation.


CONCLUSIONS
The effect of 4 Gy X-radiation to mMSC was time-dependent in the form of cellular apoptosis in the early period and cellular senescence in the late period. Non-canonical Wnt signaling may be involved in mMSC senescence induced by 4 Gy X-radiation.
Department of Hematology, Weifang People's Hospital, Weifang, P.R. China.
Wenxia
W
Su
Yonghong
Y
Chen
Wen
W
Zeng
Wenli
W
Liu
Hanying
H
Sun
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000528:radiation effects; D016193:G1 Phase / Q000528:radiation effects; D059630:Mesenchymal Stem Cells / Q000528:radiation effects*; D051379:Mice; D051153:Wnt Proteins / Q000502:physiology; D060449:Wnt Signaling Pathway / Q000502:physiology*; D000071818:Wnt-5a Protein; D060509:Wnt3A Protein / Q000502:physiology; D014965:X-Rays
D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D060509:Wnt3A Protein; C555511:Wnt3a protein, mouse; C438615:Wnt5a protein, mouse