Laboratório de Sistemática de Collembola e Conservação, Universidade Estadual da Paraíba Campus V, Centro de Ciências Biológicas e Sociais Aplicadas, Depto. Biologia. 58070-450 João Pessoa, PB, Brazil; Laboratório de Ecofisiologia Animal, Universidade Estadual da Paraíba Campus V, Centro de Ciências Biológicas e Sociais Aplicadas, Depto. Biologia. 58070-450 João Pessoa, PB, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Zoologia, Universidade Federal da Paraíba Campus I, Centro de Ciências Exatas e da Natureza, Depto. Biologia. 58051-900 João Pessoa, PB, Brazil.
Laboratório de Sistemática de Collembola e Conservação, Universidade Estadual da Paraíba Campus V, Centro de Ciências Biológicas e Sociais Aplicadas, Depto. Biologia. 58070-450 João Pessoa, PB, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Zoologia, Universidade Federal da Paraíba Campus I, Centro de Ciências Exatas e da Natureza, Depto. Biologia. 58051-900 João Pessoa, PB, Brazil.
Comp Biochem Physiol C Toxicol Pharmacol. 2021 Jan;239:108850. doi: 10.1016/j.cbpc.2020.108850. Epub 2020 Aug 7.
ATP-binding cassette (ABC) efflux pumps mediate the activity of the Multixenobiotic Resistance (MXR) mechanism and have been proposed as a biomarker of environmental pollution mainly in aquatic invertebrates. MXR activity was never investigated in Collembola and represents a potential tool for soil biomonitoring. This study aimed to characterize for the first time the activity of ABC efflux pumps in the gut of collembolan species, and investigate its responsiveness to cadmium (Cd), a common stressor found in polluted soils. We performed in vitro rhodamine-B accumulation assays in the presence of model inhibitors of ABC efflux pumps: verapamil hydrochloride as P-gp (P-glycoprotein) inhibitor, and MK571, as MRPs (multidrug resistance-related proteins) inhibitor. We also performed rhodamine-B accumulation assays under Cd-exposure (209 μg/L;1 μM). Our results showed that all species presented basal (noninduced) level of MXR activity in their gut. Efflux pumps P-gp and/or MRPs activity were confirmed in Cyphoderus innominatus, Cyphoderus similis, and Folsomia candida, the standard species. The rhodamine-B accumulation assays performed with Cd, applied as soil pollutant, showed that the gut of non-standard species C. similis and Trogolaphysa sp. presented an increase of MXR activity for both P-gp and MRP transporters, indicating the potential of these species as test organisms for soil ecotoxicology studies in Neotropical region. Our findings suggest a functional role of ABC transporters in the collembolan gut and their cellular involvement in Cd defense response, corroborating that MXR phenotype in Collembola can be a promising tool for bioindication of soil contamination.
三磷酸腺苷结合盒（ABC）外排泵介导多药耐药（MXR）机制的活性，并且已被提议作为主要在水生无脊椎动物中环境污染的生物标志物。MXR 活性从未在弹尾目动物中进行过研究，它是土壤生物监测的潜在工具。本研究旨在首次表征弹尾目物种肠道中 ABC 外排泵的活性，并研究其对镉（Cd）的响应，Cd 是污染土壤中常见的应激物。我们在存在 ABC 外排泵模型抑制剂的情况下进行了体外罗丹明 B 积累测定：盐酸维拉帕米作为 P-糖蛋白（P-gp）抑制剂，MK571 作为多药耐药相关蛋白（MRPs）抑制剂。我们还在 Cd 暴露（209μg/L；1μM）下进行了罗丹明 B 积累测定。我们的结果表明，所有物种的肠道都表现出基础（未诱导）水平的 MXR 活性。在 Cyphoderus innominatus、Cyphoderus similis 和 Folsomia candida 等标准物种中，确认了外排泵 P-gp 和/或 MRPs 的活性。用 Cd 进行的罗丹明 B 积累测定，作为土壤污染物应用，表明非标准物种 C. similis 和 Trogolaphysa sp. 的肠道中 P-gp 和 MRP 转运蛋白的 MXR 活性增加，表明这些物种作为新热带地区土壤生态毒理学研究的测试生物的潜力。我们的研究结果表明 ABC 转运蛋白在弹尾目肠道中具有功能作用，并且它们在 Cd 防御反应中的细胞参与，证实了弹尾目 MXR 表型可以作为土壤污染生物标志物的有前途的工具。
