Testing Strategies of the In Vitro Micronucleus Assay for the Genotoxicity Assessment of Nanomaterials in BEAS-2B Cells

The evaluation of the frequency of micronuclei (MN) is a broadly utilised approach in in vitro toxicity testing. Nevertheless, the specific properties of nanomaterials (NMs) give rise to concerns regarding the optimal methodological variants of the MN assay. In bronchial epithelial cells (BEAS-2B), we tested the genotoxicity of five types of NMs (TiO2: NM101, NM103; SiO2: NM200; Ag: NM300K, NM302) using four variants of MN protocols, differing in the time of exposure and the application of cytochalasin-B combined with the simultaneous and delayed co-treatment with NMs. Using transmission electron microscopy, we evaluated the impact of cytochalasin-B on the transport of NMs into the cells. To assess the behaviour of NMs in a culture media for individual testing conditions, we used dynamic light scattering measurement. The presence of NMs in the cells, their intracellular aggregation and dispersion properties were comparable when tests with or without cytochalasin-B were performed. The genotoxic potential of various TiO2 and Ag particles differed (NM101 < NM103 and NM302 < NM300K, respectively). The application of cytochalasin-B tended to increase the percentage of aberrant cells. In conclusion, the comparison of the testing strategies revealed that the level of DNA damage induced by NMs is affected by the selected methodological approach. This fact should be considered in the interpretation of the results of genotoxicity tests

Ordinary Gasoline Emissions Induce a Toxic Response in Bronchial Cells Grown at Air-Liquid Interface

Gasoline engine emissions have been classified as possibly carcinogenic to humans and represent a significant health risk. In this study, we used MucilAir™, a three-dimensional (3D) model of the human airway, and BEAS-2B, cells originating from the human bronchial epithelium, grown at the air-liquid interface to assess the toxicity of ordinary gasoline exhaust produced by a direct injection spark ignition engine. The transepithelial electrical resistance (TEER), production of mucin, and lactate dehydrogenase (LDH) and adenylate kinase (AK) activities were analyzed after one day and five days of exposure. The induction of double-stranded DNA breaks was measured by the detection of histone H2AX phosphorylation. Next-generation sequencing was used to analyze the modulation of expression of the relevant 370 genes. The exposure to gasoline emissions affected the integrity, as well as LDH and AK leakage in the 3D model, particularly after longer exposure periods. Mucin production was mostly decreased with the exception of longer BEAS-2B treatment, for which a significant increase was detected. DNA damage was detected after five days of exposure in the 3D model, but not in BEAS-2B cells. The expression of CYP1A1 and GSTA3 was modulated in MucilAir™ tissues after 5 days of treatment. In BEAS-2B cells, the expression of 39 mRNAs was affected after short exposure, most of them were upregulated. The five days of exposure modulated the expression of 11 genes in this cell line. In conclusion, the ordinary gasoline emissions induced a toxic response in MucilAir™. In BEAS-2B cells, the biological response was less pronounced, mostly limited to gene expression changes

How Do Stakeholders Working on the Forest-Water Nexus Perceive Payments for Ecosystem Services?

Nowadays, great emphasis is placed on the relationship between forest and water because forests are considered as substantial sources of many water ecosystem services. The aim of this paper is to analyze the stakeholder opinions towards the relationship between forests and water and the potential development of water-related payments for ecosystem services (PES) schemes. The study is developed in the context of COST Action CA15206-PESFOR-W (Forests for Water) aimed at synthesizing current knowledge about the PES schemes across Europe. The stakeholder opinions were mapped out using a structured questionnaire consisting of 20 questions divided into four thematic sections. The data were collected through an online survey. The results showed opinions of 142 stakeholders from 23 countries, mainly from Eastern Europe and the Mediterranean Basin. In order to analyze the collected data, the stakeholders were grouped in buyers, sellers, intermediaries, and knowledge providers. The survey results indicated that the most important category of water ecosystem services according to our sample of stakeholders is regulating services followed by provisioning services. Further findings pointed out the highest importance that shared values and direct changes in land management can have when designing water-related PES schemes. The role of public authorities and collective collaboration of different stakeholders, with emphasis on local and expert knowledge, are also identified as of crucial importance. The results show that stakeholder opinions can serve as a starting point when designing PES schemes