与DNA修复相关的核酶在对UVA1和UVB的连续暴露后诱导双链断裂
Mai Narimichi1, Yukako Komaki1,2, Takashi Suzuki1
1Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
概括
连续的UVA1和UVB暴露会导致角质细胞中的DNA双链断裂 (DSB). 这发生在UVB损伤的核酸切除修复 (NER) 被UVA1稳定时,通过EXO1和MRE11核酶导致DSB形成.
科学领域:
- 分子生物学分子生物学
- 皮肤病学 皮肤病学
- 遗传学 是一个遗传学.
背景情况:
- 太阳紫外线 (UV) 辐射,包括UVA和UVB,具有明显的生物效应.
- 顺序性UVA1和UVB暴露对人类角质细胞及其潜在机制的综合影响仍然不完全理解.
- 之前的研究表明,在顺序的UVA1和UVB照射后,严重的细胞死亡和DNA双链断裂 (DSB) 形成.
研究的目的:
- 在连续UVA1和UVB暴露后确认DSB的形成.
- 研究驱动人类角质细胞中DSB形成的分子机制.
- 为了确定参与这个过程的特定核酶.
主要方法:
- 使用偏向的正弦形场凝电泳,验证DSB形成.
- 作为DNA损伤标记物,检测化组合素H2AX和RPA.
- 在Xeroderma pigmentosum (XP) 突变细胞系中评估DSB诱导.
- 在紫外线损坏的地点分析RPA和PCNA的积累.
- 通过敲击和特定抑制研究核酶EXO1和MRE11的作用.
主要成果:
- 经过连续的UVA1和UVB暴露后证实了DSB的形成.
- 在XP突变细胞系中没有DSB诱导,这意味着核酸切除修复 (NER) 在这个过程中.
- 在UVA1前辐射稳定了NER介导的单链DNA (ssDNA) 缺口,由持续的RPA积累表明.
- Knockdown 的 EXO1 和 MRE11 显著抑制了 DSB 的形成.
- 抑制MRE11内核酶活性,但不抑制外核酶活性,抑制了DSB的形成.
结论:
- 紫外线B诱导的胺二聚体的NER,通过UVA1暴露稳定,触发DSB的形成.
- EXO1扩展了ssDNA间隙,MRE11引入了一个,导致DSB形成.
- 这一途径突出了UV诱导的DNA损伤的新机制.
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