Expression and possible mechanism of c-ski, a novel tissue repair-related gene during normal and radiation-impaired wound healing.
C-ski is a complicated regulating factor for fibroblast proliferation and an important co-repressor of Smad3. Although inhibiting Smad3 activity can markedly promote wound healing because Smad3 mediates the role of transforming growth factor-beta in inhibiting cell proliferation and inducing cell apoptosis; there has been no report on whether c-ski is expressed during wound healing and the relationship between its expression and wound healing. By establishing animal models of normal and radiation-impaired wound healing and using immunohistochemistry, in situ hybridization, and reverse transcription-polymerase chain reaction, we found that c-ski was expressed after wounding and reached its peak on day 9 and then significantly decreased. C-ski was present in all repair cells, and was especially prominent in fibroblasts. Compared with the control side, the irradiated side showed a lower expression of c-ski on postwound days 3-9, but higher on day 15, and not significantly different after the wound was healed. The expression of Smad3 was in contrast to the c-ski and cellular proliferation was similar to that of c-ski expression. The apoptosis index was significantly higher on the irradiated side on days 3-9 compared with the control side. In vitro, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide results showed that c-ski could reverse the inhibitory role of Smad3 on fibroblast proliferation. Flow cytometry analysis found that c-ski also diminished fibroblast apoptosis induced by Smad3 transfection. These results suggest that there is not only obvious expression of this regulatory protein but there is also a significant change in the levels of c-ski during wound healing. Its in vivo expression pattern and experiments in vitro suggest that c-ski may be involved in tissue repair by repressing Smad3 activity. Radiation can reduce c-ski and increase Smad3 expression, resulting in elevated Smad3 activity, resulting in diminished cell proliferation, cell apoptosis, and wound-healing delays.
Liu
Xia
X
Molecular Biology Center, Research Institute of Surgery, Da Ping Hospital, Chongqing City, People's Republic of China.
Zhang
En
E
Li
Ping
P
Liu
Jianzhong
J
Zhou
Ping
P
Gu
Da-yong
DY
Chen
Xingyun
X
Cheng
Tianmin
T
Zhou
Yuanguo
Y
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects; D005434:Flow Cytometry; D015870:Gene Expression; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D051900:Smad3 Protein / Q000037:antagonists & inhibitors; D014945:Wound Healing / Q000502:physiology* / Q000528:radiation effects
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D051900:Smad3 Protein