Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes-RJ, 28013-602, Brazil.
Probiotics Antimicrob Proteins. 2024 Apr;16(2):649-672. doi: 10.1007/s12602-023-10064-8. Epub 2023 Apr 20.
The management of fungal diseases imposes an urgent need for the development of effective antifungal drugs. Among new drug candidates are the antimicrobial peptides, and especially their derivatives. Here, we investigated the molecular mechanism of action of three bioinspired peptides against the opportunistic yeasts Candida tropicalis and Candida albicans. We assessed morphological changes, mitochondrial functionality, chromatin condensation, ROS production, activation of metacaspases, and the occurrence of cell death. Our results indicated that the peptides induced sharply contrasting death kinetics, of 6 h for RR and 3 h for D-RR to C. tropicalis and 1 h for WR to C. albicans. Both peptide-treated yeasts exhibited increased ROS levels, mitochondrial hyperpolarization, cell size reduction, and chromatin condensation. RR and WR induced necrosis in C. tropicalis and C. albicans, but not D-RR in C. tropicalis. The antioxidant ascorbic acid reverted the toxic effect of RR and D-RR, but not WR, suggesting that instead of ROS there is a second signal triggered that leads to yeast death. Our data suggest that RR induced a regulated accidental cell death in C. tropicalis, D-RR induced a programmed cell death metacaspase-independent in C. tropicalis, while WR induced an accidental cell death in C. albicans. Our results were obtained with the LD and within the time that the peptides induce the yeast death. Within this temporal frame, our results allow us to gain clarity on the events triggered by the peptide-cell interaction and their temporal order, providing a better understanding of the death process induced by them.
真菌病的治疗迫切需要开发有效的抗真菌药物。新的候选药物包括抗菌肽，尤其是它们的衍生物。在这里，我们研究了三种受生物启发的肽对机会性酵母热带假丝酵母和白色念珠菌的作用机制。我们评估了形态变化、线粒体功能、染色质凝聚、ROS 产生、介体型半胱氨酸蛋白酶的激活以及细胞死亡的发生。我们的结果表明，这些肽诱导了截然不同的死亡动力学，RR 和 D-RR 对 C. tropicalis 的作用时间为 6 小时，WR 对 C. albicans 的作用时间为 3 小时。两种肽处理的酵母均表现出 ROS 水平升高、线粒体超极化、细胞大小减小和染色质凝聚。RR 和 WR 在 C. tropicalis 和 C. albicans 中诱导坏死，但 D-RR 在 C. tropicalis 中没有。抗氧化剂抗坏血酸使 RR 和 D-RR 的毒性作用逆转，但 WR 没有，这表明不是 ROS，而是触发酵母死亡的第二个信号。我们的数据表明，RR 在 C. tropicalis 中诱导了一种调节性偶然细胞死亡，D-RR 在 C. tropicalis 中诱导了一种不依赖于介体型半胱氨酸蛋白酶的程序性细胞死亡，而 WR 在 C. albicans 中诱导了一种偶然细胞死亡。我们的结果是在 LD 下获得的，并且在肽诱导酵母死亡的时间内。在这个时间框架内，我们的结果使我们能够更清楚地了解肽-细胞相互作用触发的事件及其时间顺序，从而更好地理解它们诱导的死亡过程。
