Gualandris Davide, Rotondo Davide, Lorusso Candida, La Terza Antonietta, Calisi Antonio, Dondero Francesco
Department of Science and Technological Innovation, Università degli Studi del Piemonte Orientale, Viale Michel 11, 15121 Alessandria, Italy.
School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy.
Toxics. 2024 Oct 8;12(10):725. doi: 10.3390/toxics12100725.
Metallothioneins are multifunctional proteins implicated in various cellular processes. They have been used as biomarkers of heavy metal exposure and contamination due to their intrinsic ability to bind heavy metals and their transcriptional response to both physiological and noxious metal ions such as cadmium (Cd) and mercury (Hg). In this study, we aimed to clarify the role of iron and reactive oxygen species (ROSs) in the induction of the metallothionein system (Mtt) in the ciliate protozoan . We investigated the relative mRNA abundances of the metallothionein genes Mtt1, Mtt2/4, and Mtt5, revealing for the first time their responsiveness to iron exposure. Furthermore, by using inhibitors of superoxide dismutase (SOD) and catalase (CAT), alone or in combination with iron, we highlighted the roles of superoxide ion and endogenous hydrogen peroxide, as well as the complex interplay between the metal and ROSs. These results enhance our understanding of the metallothionein system in ciliates and suggest that ROSs may be a primary evolutionary driver for the selection of these proteins in nature.
金属硫蛋白是参与多种细胞过程的多功能蛋白质。由于它们具有结合重金属的内在能力以及对生理和有害金属离子（如镉（Cd）和汞（Hg））的转录反应，它们已被用作重金属暴露和污染的生物标志物。在本研究中，我们旨在阐明铁和活性氧（ROS）在纤毛虫原生动物中金属硫蛋白系统（Mtt）诱导中的作用。我们研究了金属硫蛋白基因Mtt1、Mtt2/4和Mtt5的相对mRNA丰度，首次揭示了它们对铁暴露的反应性。此外，通过单独或与铁联合使用超氧化物歧化酶（SOD）和过氧化氢酶（CAT）抑制剂，我们突出了超氧离子和内源性过氧化氢的作用，以及金属与ROS之间的复杂相互作用。这些结果增进了我们对纤毛虫中金属硫蛋白系统的理解，并表明ROS可能是自然界中选择这些蛋白质的主要进化驱动力。
