Wild-type p53-induced phosphatase l combined with bmil in repairing ion radiation-induced dna damage in nucleus pulposus cells
10.3724/SP.J.1008.2013.00909
- Author:
Lei YU
1
Author Information
1. Department of Clinical Laboratory, The Tenth Peoples 'Hospital of Shanghai Tongii University'
- Publication Type:Journal Article
- Keywords:
Bmil;
Dnarepair;
Intervertebral disc degeneration;
Radiation injuries;
Wipl
- From:
Academic Journal of Second Military Medical University
2013;34(8):909-913
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the possible role of wild-type p53-induced phosphatase 1 (Wip1) in repairing radiation-induced DNA damage in nucleus pulposus (NP) cells, so as to provide reference for treatment of intervertebral disc degeneration. Methods Human NP cells were cultured in vitro and the expression of Wip1 was knocked down by small interfering (siRNA) technology; the NP cells were exposed to radiation (4,10,15 and 25 Gy). DNA damage and repair were observed by comet assay, and the results were compared with NP cells not treated by siRNA. Co-immunoprecipitation (Co-IP) was used to detect the potential binding protein of Wip1, and based on the screening results, qRT-PCR was used to examine Wip1 expression and expression of potential binding protein. Results Comet assay showed that the repair of DNA damage in Wip1 knockdown NP cells was not affected when exposed to 25 Gy radiation, but DNA damage repair was persistently reactivated. The markermolecules of DNAdamage repair were not detectable 24 h after radiation in the control group, but they could be detected 48 h after radiation in Wip1 knockdown group. Co-IP results showed that the distribution of Wip1 and Bmi1 coincided in the nuclei of normal cells exposed to radiation, aggregating at the DNA damage site, and the coincidence disappeared after knockdown of Wip1. qRT-PCR results showed that, compared with the normal intervertebral tissues, degenerated intervertebral tissues had significantly decreased Wp1 and Bmi1 expression, and the expression of Wip1 was positively correlated with Bmi1 expression (P<0. 05). Conclusion Wip1 plays an important role in the DNA damage repair of NP cells by regulating DNA damage repair phase, and Bmi1 may also participate in this process.
