Kowalska Patrycja, Mierzejewska Jolanta, Skrzeszewska Paulina, Witkowska Aleksandra, Oksejuk Katarzyna, Sitkiewicz Ewa, Krawczyk Mariusz, Świadek Magdalena, Głuchowska Agata, Marlicka Klaudia, Sobiepanek Anna, Milner-Krawczyk Małgorzata
Chair of Drug and Cosmetics Biotechnology, Warsaw University of Technology, Warsaw, Poland.
Doctoral School Warsaw University of Technology, Warsaw, Poland.
Appl Microbiol Biotechnol. 2024 Dec 5;108(1):529. doi: 10.1007/s00253-024-13358-1.
Violacein is a natural indole-derived purple pigment of microbial origin that has attracted attention for its remarkable biological properties. Due to its poor solubility in aqueous media, most studies of this pigment use extracts of the compound obtained with common solvents. Violacein is also transported in bacterial extracellular vesicles (EVs) and transferred via this type of carrier remains stable in an aqueous environment. This paper is the first to present an in-depth study of Janthinobacterium lividum EVs as violacein carriers. J. lividum EVs were studied for their contribution to violacein translocation, size, morphology and protein composition. The production of violacein encapsulated in EVs was more efficient than the intracellular production of this compound. The average size of the violacein-containing EVs was 124.07 ± 3.74 nm. Liquid chromatography-tandem mass spectrometry analysis (LC-MS/MS) revealed 932 proteins common to three independent EVs isolations. The high proportion of proteins with intracellular localisation, which are involved in many fundamental cellular processes, suggests that J. lividum EVs could be generated in a cell lysis model, additionally stimulated by violacein production. Using human keratinocytes and melanoma cell lines, it was confirmed that J. lividum EVs are able to react with and deliver their cargo to mammalian cells. The EVs-delivered violacein was shown to retain its activity against melanoma cells, and the dose and timing of treatment can be selected to target only cancer cells. The characterisation of J. lividum EVs, described in the following paper, represents a milestone for their future potential anticancer application. KEY POINTS: • This report focuses on the investigation of Janthinobacterium lividum EVs as a new delivery vehicle for violacein, a compound with a previously demonstrated broad spectrum of activity. • EVs were characterised for size, morphology and protein composition. • Studies on human keratinocytes and a melanoma cell model confirmed that the activity of violacein applied in the encapsulated form of EVs is similar to that of its organic solvent extract, but their production is much more environmentally friendly.
紫罗碱是一种源自微生物的天然吲哚类紫色色素，因其显著的生物学特性而备受关注。由于其在水性介质中的溶解度较差，对这种色素的大多数研究都使用用常见溶剂获得的该化合物提取物。紫罗碱也会被运输到细菌细胞外囊泡（EVs）中，并且通过这种类型的载体转运在水性环境中保持稳定。本文首次对作为紫罗碱载体的青枯假单胞菌EVs进行了深入研究。对青枯假单胞菌EVs在紫罗碱转运、大小、形态和蛋白质组成方面的作用进行了研究。包裹在EVs中的紫罗碱的产生比该化合物的细胞内产生更有效。含紫罗碱的EVs的平均大小为124.07±3.74纳米。液相色谱-串联质谱分析（LC-MS/MS）揭示了三次独立的EVs分离中共有的932种蛋白质。参与许多基本细胞过程的具有细胞内定位的蛋白质比例很高，这表明青枯假单胞菌EVs可能是在细胞裂解模型中产生的，此外还受到紫罗碱产生的刺激。使用人角质形成细胞和黑色素瘤细胞系，证实了青枯假单胞菌EVs能够与哺乳动物细胞反应并递送其货物。EVs递送的紫罗碱显示出对黑色素瘤细胞保持其活性，并且可以选择治疗的剂量和时间仅靶向癌细胞。下文所述的青枯假单胞菌EVs的表征代表了它们未来潜在抗癌应用的一个里程碑。要点：• 本报告重点研究了青枯假单胞菌EVs作为紫罗碱的一种新的递送载体，紫罗碱是一种先前已证明具有广泛活性谱的化合物。• 对EVs的大小、形态和蛋白质组成进行了表征。• 对人角质形成细胞和黑色素瘤细胞模型的研究证实，以EVs包裹形式应用的紫罗碱的活性与其有机溶剂提取物的活性相似，但其生产对环境更友好。
