Ayyildiz Dilara, Arga Kazim Yalcin, Avci Fatma Gizem, Altinisik Fatma Ece, Gurer Caglayan, Gulsoy Toplan Gizem, Kazan Dilek, Wozny Katharina, Brügger Britta, Mertoglu Bulent, Sariyar Akbulut Berna
Department of Bioengineering, Faculty of Engineering, Marmara University, Building D, Office:321, 34722, Kadikoy, Istanbul, Turkey.
Department of Pharmacognosy, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey.
Curr Genet. 2017 Aug;63(4):709-722. doi: 10.1007/s00294-016-0673-4. Epub 2016 Dec 24.
Among the different families of plant alkaloids, (-)-roemerine, an aporphine type, was recently shown to possess significant antibacterial activity in Escherichia coli. Based on the increasing demand for antibacterials with novel mechanisms of action, the present work investigates the potential of the plant-derived alkaloid (-)-roemerine as an antibacterial in E. coli cells using microarray technology. Analysis of the genome-wide transcriptional reprogramming in cells after 60 min treatment with 100 μg/mL (-)-roemerine showed significant changes in the expression of 241 genes (p value <0.05 and fold change >2). Expression of selected genes was confirmed by qPCR. Differentially expressed genes were classified into functional categories to map biological processes and molecular pathways involved. Cellular activities with roles in carbohydrate transport and metabolism, energy production and conversion, lipid transport and metabolism, amino acid transport and metabolism, two-component signaling systems, and cell motility (in particular, the flagellar organization and motility) were among metabolic processes altered in the presence of (-)-roemerine. The down-regulation of the outer membrane proteins probably led to a decrease in carbohydrate uptake rate, which in turn results in nutrient limitation. Consequently, energy metabolism is slowed down. Interestingly, the majority of the expressional alterations were found in the flagellar system. This suggested reduction in motility and loss in the ability to form biofilms, thus affecting protection of E. coli against host cell defense mechanisms. In summary, our findings suggest that the antimicrobial action of (-)-roemerine in E. coli is linked to disturbances in motility and nutrient uptake.
在不同的植物生物碱家族中，阿朴啡型的（-）-罗默碱最近被证明对大肠杆菌具有显著的抗菌活性。基于对具有新型作用机制抗菌剂的需求不断增加，本研究使用微阵列技术研究了植物来源的生物碱（-）-罗默碱作为大肠杆菌细胞抗菌剂的潜力。用100μg/mL（-）-罗默碱处理60分钟后，对细胞中全基因组转录重编程的分析表明，241个基因的表达发生了显著变化（p值<0.05且倍数变化>2）。通过qPCR确认了所选基因的表达。将差异表达的基因分类为功能类别，以绘制所涉及的生物学过程和分子途径。在（-）-罗默碱存在下，碳水化合物运输和代谢、能量产生和转换、脂质运输和代谢、氨基酸运输和代谢、双组分信号系统以及细胞运动（特别是鞭毛组织和运动）等细胞活动在代谢过程中发生了改变。外膜蛋白的下调可能导致碳水化合物摄取率降低，进而导致营养限制。因此，能量代谢减慢。有趣的是，大多数表达变化发生在鞭毛系统中。这表明运动性降低和形成生物膜的能力丧失，从而影响大肠杆菌对宿主细胞防御机制的保护。总之，我们的研究结果表明，（-）-罗默碱在大肠杆菌中的抗菌作用与运动性和营养摄取的紊乱有关。
