Gozzi Kevin, Ching Carly, Paruthiyil Srinand, Zhao Yinjuan, Godoy-Carter Veronica, Chai Yunrong
Department of Biology, Northeastern University, Boston, MA 02115 USA.
College of Forestry resources and environment, Nanjing Forestry University, Nanjing, 210037 China.
NPJ Biofilms Microbiomes. 2017 Mar 24;3:8. doi: 10.1038/s41522-017-0016-3. eCollection 2017.
Bacteria switch between free-living and a multicellular state, known as biofilms, in response to cellular and environmental cues. It is important to understand how these cues influence biofilm development as biofilms are not only ubiquitous in nature but are also causative agents of infectious diseases. It is often believed that any stress triggers biofilm formation as a means of bacterial protection. In this study, we propose a new mechanism for how cellular and environmental DNA damage may influence biofilm formation. We demonstrate that prevents biofilm formation and cell differentiation when stressed by oxidative DNA damage. We show that during biofilm development, a subpopulation of cells accumulates reactive oxygen species, which triggers the DNA damage response Surprisingly, DNA damage response induction shuts off matrix genes whose products permit individual cells to stick together within a biofilm. We further revealed that DDR cells and matrix producers are mutually exclusive and spatially separated within the biofilm, and that a developmental checkpoint protein, Sda, mediates the exclusiveness. We believe this represents an alternative survival strategy, ultimately allowing cells to escape the multicellular community when in danger.
细菌会根据细胞和环境信号在自由生活状态和称为生物膜的多细胞状态之间转换。了解这些信号如何影响生物膜的形成很重要,因为生物膜不仅在自然界中普遍存在,而且还是传染病的病原体。人们通常认为任何压力都会触发生物膜形成,作为细菌保护的一种手段。在这项研究中,我们提出了一种关于细胞和环境DNA损伤如何影响生物膜形成的新机制。我们证明,当受到氧化性DNA损伤应激时,会阻止生物膜形成和细胞分化。我们表明,在生物膜发育过程中,一部分细胞会积累活性氧,这会触发DNA损伤反应。令人惊讶的是,DNA损伤反应的诱导会关闭其产物允许单个细胞在生物膜内粘在一起的基质基因。我们进一步揭示,DDR细胞和基质产生细胞在生物膜内相互排斥且在空间上分离,并且一种发育检查点蛋白Sda介导了这种排斥性。我们认为这代表了一种替代的生存策略,最终使细胞在危险时能够逃离多细胞群落。