Effect of a large-sized silicone sheet upon recovery of mastoid aeration after mastoidectomy

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• 作者：Kyosuke Kazama ; Haruo Takahashi ; Satoru Kaieda ; Tetsu Iwanaga ; Tomomi Yamamoto-Fukuda ; Haruo Yoshida ; Hidetaka Kumagami ; Kenji Takasaki
• 关键词：PARP-1 ; DNA repair ; Base excision repair ; Single strand break
• 刊名：Otolaryngology - Head and Neck Surgery
• 出版年：2008
• 出版时间：June 2008
• 年：2008
• 卷：138
• 期：6
• 页码：738-742
• 全文大小：592 K

文摘

Although poly(ADP-ribose) polymerase-1 (PARP-1) has no enzymatic activity involved in DNA damage processing by the base excision repair (BER) pathway, PARP-1 deficient cells are genetically unstable and sensitive to DNA-damaging agents. To explain this paradox, we investigated the impact of PARP-1 on BER in mammalian cells. We reduced cellular PARP-1 protein levels using siRNA, then introduced DNA damage by hydrogen peroxide treatment and examined the repair response. We find that PARP-1 is not involved in recruitment of the major BER proteins to sites of DNA damage. However, we find that PARP-1 protects excessive DNA single strand breaks (SSBs) from converting into DNA double strand breaks (DSBs) thus preserving them for subsequent repair by BER enzymes. This suggests that PARP-1 plays an important role in BER by extending the ability of BER enzymes to process DNA single strand breaks arising directly after mutagen stress or during processing of DNA lesions following extensive DNA damage.