A highly conserved SOX6 double binding site mediates SOX6 gene downregulation in erythroid cells

The Sox6 transcription factor plays critical roles in various cell types, including erythroid cells. Sox6-deficient mice are anemic due to impaired red cell maturation and show inappropriate globin gene expression in definitive erythrocytes. To identify new Sox6 target genes in erythroid cells, we used the known repressive double Sox6 consensus within the εy-globin promoter to perform a bioinformatic genome-wide search for similar, evolutionarily conserved motifs located within genes whose expression changes during erythropoiesis. We found a highly conserved Sox6 consensus within the Sox6 human gene promoter itself. This sequence is bound by Sox6 in vitro and in vivo, and mediates transcriptional repression in transient transfections in human erythroleukemic K562 cells and in primary erythroblasts. The binding of a lentiviral transduced Sox6FLAG protein to the endogenous Sox6 promoter is accompanied, in erythroid cells, by strong downregulation of the endogenous Sox6 transcript and by decreased in vivo chromatin accessibility of this region to the PstI restriction enzyme. These observations suggest that the negative Sox6 autoregulation, mediated by the double Sox6 binding site within its own promoter, may be relevant to control the Sox6 transcriptional downregulation that we observe in human erythroid cultures and in mouse bone marrow cells in late erythroid maturation

Online Solid-Phase Extraction LC-MS/MS: A Rapid and Valid Method for the Determination of Perfluorinated Compounds at Sub ng·L−1 Level in Natural Water

In this research paper, we report a method able to detect perfluorinated compound at pg·L−1 levels in superficial and underground water samples. An online solid phase extraction HPLC-MS/MS method was developed for the analysis of 12 perfluoroalkyl acids (PFASs). The method is based on injection of 5000 µL of water sample in SPE online WAX column followed by chromatography separation and mass spectrometry determination. SPE online elution was performed by water + 0.05% NH4OH and methanol + 0.05% NH4OH, while separation of target compounds was achieved within 10 min by Gemini chromatographic column operating from 1 to 12 pH range and using a mixture of water-methanol + 0.05% NH4OH. Sub ng·L−1 method detection limits (from 0.2 to 5 ng·L−1), linearity (from 0.2 to 250 ng·L−1), accuracy (from 80 to 120%), and precision (RSD less than 15% at LOQs levels) were achieved. The method is capable of measuring PFAS at trace levels, but above all it can reach the limit of 200 pg·L−1 required by European regulation for PFOS determination in surface and underground waters. The method was validated for quantitative analysis of PFASs in real water samples

Determination of Antibiotics, Pesticides, Herbicides, Fungicides and Hormones in Water Bodies in Italy in Occurrence with European Watch List Mechanism by Using an UHPLC-MS/MS System: Method Validation, Quantification and Evaluations

In recent years, the quality of aquatic ecosystems has received increasing attention from European institutions. The Commission Implementing Decision (EU) 2018/840 drafted a Watch List (WL) of compounds to be monitored in Europe. In this study, we report a method based on solid phase extraction with ultra-high-performance liquid chromatography, coupled with a triple-quadrupole mass spectrometer (UHPLC-MS/MS) to analyze the whole water sample. The method was developed and validated for the determination of 12 listed compounds. The employment of solid-phase extraction by a horizon system ensures the analysis of the entire body of samples and minimizes sample manipulation. Different ng L−1 detection limits (from 2 to 50 ng L−1), linearities (from 2 to 500 ng L−1), accuracy (from 70 to 130%) and levels of precision (RSD less 20% at LOQs levels) were assessed to be satisfactory for quantification and confirmation at the levels of interest. The developed method was applied for quantitative analysis for Watch List compounds (with the exception of hormones) in surface water samples from different Italian sites during monitoring activities by the Regional Environmental Protection Agencies in the years 2019 and 2020

Determination of Antibiotics, Pesticides, Herbicides, Fungicides and Hormones in Water Bodies in Italy in Occurrence with European Watch List Mechanism by Using an UHPLC-MS/MS System: Method Validation, Quantification and Evaluations

In recent years, the quality of aquatic ecosystems has received increasing attention from European institutions. The Commission Implementing Decision (EU) 2018/840 drafted a Watch List (WL) of compounds to be monitored in Europe. In this study, we report a method based on solid phase extraction with ultra-high-performance liquid chromatography, coupled with a triple-quadrupole mass spectrometer (UHPLC-MS/MS) to analyze the whole water sample. The method was developed and validated for the determination of 12 listed compounds. The employment of solid-phase extraction by a horizon system ensures the analysis of the entire body of samples and minimizes sample manipulation. Different ng L−1 detection limits (from 2 to 50 ng L−1), linearities (from 2 to 500 ng L−1), accuracy (from 70 to 130%) and levels of precision (RSD less 20% at LOQs levels) were assessed to be satisfactory for quantification and confirmation at the levels of interest. The developed method was applied for quantitative analysis for Watch List compounds (with the exception of hormones) in surface water samples from different Italian sites during monitoring activities by the Regional Environmental Protection Agencies in the years 2019 and 2020

Summary recommendations on “Analytical methods for substances in the Watch List under the Water Framework Directive”

The Watch List (WL) is a monitoring program under the European Water Framework Directive (WFD) to obtain high-quality Union-wide monitoring data on potential water pollutants for which scarce monitoring data or data of insufficient quality are available. The main purpose of the WL data collection is to determine if the substances pose a risk to the aquatic environment at EU level and subsequently to decide whether a threshold, the Environmental Quality Standards (EQS) should be set for them and, potentially to be listed as priority substance in the WFD. The first WL was established in 2015 and contained 10 individual or groups of substances while the 4th WL was launched in 2022. The results of monitoring the substances of the first WL showed that some countries had difficulties to reach an analytical Limit of Quantification (LOQ) below or equal to the Predicted No-Effect Concentrations (PNEC) or EQS. The Joint Research Centre (JRC) of the European Commission (EC) organised a series of workshops to support the EU Member States (MS) and their activities under the WFD. Sharing the knowledge among the Member States on the analytical methods is important to deliver good data quality. The outcome and the discussion engaged with the experts are described in this paper, and in addition a literature review of the most important publications on the analysis of 17-alpha-ethinylestradiol (EE2), amoxicillin, ciprofloxacin, metaflumizone, fipronil, metformin, and guanylurea from the last years is presented

Estrogenicity of chemical mixtures revealed by a panel of bioassays

International audienceEstrogenic compounds are widely released to surface waters and may cause adverse effects to sensitive aquatic species. Three hormones, estrone, 17β-estradiol and 17α-ethinylestradiol, are of particular concern as they are bioactive at very low concentrations. Current analytical methods are not all sensitive enough for monitoring these substances in water and do not cover mixture effects. Bioassays could complement chemical analysis since they detect the overall effect of complex mixtures. Here, four chemical mixtures and two hormone mixtures were prepared and tested as reference materials together with two environmental water samples by eight laboratories employing nine in vitro and in vivo bioassays covering different steps involved in the estrogenic response. The reference materials included priority substances under the European Water Framework Directive, hormones and other emerging pollutants. Each substance in the mixture was present at its proposed safety limit concentration (EQS) in the European legislation. The in vitro bioassays detected the estrogenic effect of chemical mixtures even when 17β-estradiol was not present but differences in responsiveness were observed. LiBERA was the most responsive, followed by LYES. The additive effect of the hormones was captured by ERα-CALUX, MELN, LYES and LiBERA. Particularly, all in vitro bioassays detected the estrogenic effects in environmental water samples (EEQ values in the range of 0.75–304 × EQS), although the concentrations of hormones were below the limit of quantification in analytical measurements. The present study confirms the applicability of reference materials for estrogenic effects' detection through bioassays and indicates possible methodological drawbacks of some of them that may lead to false negative/positive outcomes. The observed difference in responsiveness among bioassays – based on mixture composition - is probably due to biological differences between them, suggesting that panels of bioassays with different characteristics should be applied according to specific environmental pollution conditions