Loss of p16Ink4a Function Rescues Cellular Senescence Induced by Telomere Dysfunction

International Journal of Molecular Sciences

Xiufeng Zhang¹  Xiaoming Wu¹  Wenru Tang¹ 

[1] Faculty of Environmental Science and Engineering, Kunming University of Science & Technology, Kunming 650224, China; E-Mails:

关键词: p16^Ink4a;    Werner Syndrome;    telomere dysfunction;   

DOI  :  10.3390/ijms13055866

来源: mdpi

【 摘 要 】

p16^Ink4a is a tumor suppressor and a marker for cellular senescence. Previous studies have shown that p16^Ink4a plays an important role in the response to DNA damage signals caused by telomere dysfunction. In this study, we crossed Wrn^−/− and p16^Ink4a−/− mice to knock out the p16^Ink4a function in a Wrn null background. Growth curves showed that loss of p16^Ink4a could rescue the growth barriers that are observed in Wrn^−/− mouse embryonic fibroblasts (MEFs). By challenging the MEFs with the global genotoxin doxorubicin, we showed that loss of p16^Ink4a did not dramatically affect the global DNA damage response of Wrn^−/− MEFs induced by doxorubicin. However, in response to telomere dysfunction initiated by the telomere damaging protein TRF2^ΔBΔM, loss of p16^Ink4a could partially overcome the DNA damage response by disabling p16^Ink4a up-regulation and reducing the accumulation of γ-H2AX that is observed in Wrn^−/− MEFs. Furthermore, in response to TRF2^ΔBΔM overexpression, Wrn^−/− MEFs senesced within several passages. In contrast, p16^Ink4a−/− and p16^Ink4a−/−Wrn^−/− MEFs could continuously grow and lose expression of the exogenous TRF2^ΔBΔM in their late passages. In summary, our data suggest that in the context of telomere dysfunction, loss of p16^Ink4a function could prevent cells from senescence. These results shed light on the anti-aging strategy through regulation of p16^Ink4a expression.

【 授权许可】

CC BY   
© 2012 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.