Institut National de la Santé et de la Recherche Médicale (INSERM) U1001, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine Paris Descartes, Paris, France.
bioMérieux SA, Microbiology Unit, R&D Microbiology, La Balme les Grottes, France.
Sci Rep. 2018 Aug 14;8(1):12088. doi: 10.1038/s41598-018-30623-2.
Prokaryotic and eukaryotic cells exhibit an intrinsic natural fluorescence due to the presence of fluorescent cellular structural components and metabolites. Therefore, cellular autofluorescence (AF) is expected to vary with the metabolic states of cells. We examined how exposure to the different stressors changes the AF of Escherichia coli cells. We observed that bactericidal treatments increased green cellular AF, and that de novo protein synthesis was required for the observed AF increase. Excitation and emission spectra and increased expression of the genes from the flavin biosynthesis pathway, strongly suggested that flavins are major contributors to the increased AF. An increased expression of genes encoding diverse flavoproteins which are involved in energy production and ROS detoxification, indicates a cellular strategy to cope with severe stresses. An observed increase in AF under stress is an evolutionary conserved phenomenon as it occurs not only in cells from different bacterial species, but also in yeast and human cells.
由于荧光细胞结构成分和代谢物的存在，原核细胞和真核细胞表现出固有天然荧光。因此，细胞自发荧光（AF）预计会随细胞代谢状态而变化。我们研究了暴露于不同应激源如何改变大肠杆菌细胞的 AF。我们观察到杀菌处理增加了绿色细胞 AF，并且观察到的 AF 增加需要从头合成蛋白质。激发和发射光谱以及黄素生物合成途径基因的表达增加，强烈表明黄素是增加 AF 的主要贡献者。参与能量产生和 ROS 解毒的各种黄素蛋白编码基因的表达增加，表明细胞有策略来应对严重压力。在应激下观察到的 AF 增加是一种进化上保守的现象，因为它不仅发生在来自不同细菌物种的细胞中，也发生在酵母和人类细胞中。
