Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 181
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Mol Cell ; 84(4): 687-701.e7, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38266641

ABSTRACT

Molecular chaperones are critical for protein homeostasis and are implicated in several human pathologies such as neurodegeneration and cancer. While the binding of chaperones to nascent and misfolded proteins has been studied in great detail, the direct interaction between chaperones and RNA has not been systematically investigated. Here, we provide the evidence for widespread interaction between chaperones and RNA in human cells. We show that the major chaperone heat shock protein 70 (HSP70) binds to non-coding RNA transcribed by RNA polymerase III (RNA Pol III) such as tRNA and 5S rRNA. Global chromatin profiling revealed that HSP70 binds genomic sites of transcription by RNA Pol III. Detailed biochemical analyses showed that HSP70 alleviates the inhibitory effect of cognate tRNA transcript on tRNA gene transcription. Thus, our study uncovers an unexpected role of HSP70-RNA interaction in the biogenesis of a specific class of non-coding RNA with wider implications in cancer therapeutics.


Subject(s)
HSP70 Heat-Shock Proteins , Neoplasms , Humans , HSP70 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , Molecular Chaperones/metabolism , RNA , RNA Polymerase III/genetics , RNA Polymerase III/metabolism , RNA, Transfer/genetics , RNA, Untranslated/genetics
2.
Proc Natl Acad Sci U S A ; 120(29): e2303740120, 2023 07 18.
Article in English | MEDLINE | ID: mdl-37428914

ABSTRACT

Defining reliable surrogate markers and overcoming drug resistance are the most challenging issues for improving therapeutic outcomes of antiangiogenic drugs (AADs) in cancer patients. At the time of this writing, no biomarkers are clinically available to predict AAD therapeutic benefits and drug resistance. Here, we uncovered a unique mechanism of AAD resistance in epithelial carcinomas with KRAS mutations that targeted angiopoietin 2 (ANG2) to circumvent antivascular endothelial growth factor (anti-VEGF) responses. Mechanistically, KRAS mutations up-regulated the FOXC2 transcription factor that directly elevated ANG2 expression at the transcriptional level. ANG2 bestowed anti-VEGF resistance as an alternative pathway to augment VEGF-independent tumor angiogenesis. Most colorectal and pancreatic cancers with KRAS mutations were intrinsically resistant to monotherapies of anti-VEGF or anti-ANG2 drugs. However, combination therapy with anti-VEGF and anti-ANG2 drugs produced synergistic and potent anticancer effects in KRAS-mutated cancers. Together, these data demonstrate that KRAS mutations in tumors serve as a predictive marker for anti-VEGF resistance and are susceptible to combination therapy with anti-VEGF and anti-ANG2 drugs.


Subject(s)
Carcinoma , Endothelial Growth Factors , Humans , Endothelial Growth Factors/genetics , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Angiopoietin-2/genetics , Angiopoietin-2/metabolism , Angiopoietin-1/metabolism
3.
Toxicol Appl Pharmacol ; 489: 116995, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38862081

ABSTRACT

Identification of Endocrine-Disrupting Chemicals (EDCs) in a regulatory context requires a high level of evidence. However, lines of evidence (e.g. human, in vivo, in vitro or in silico) are heterogeneous and incomplete for quantifying evidence of the adverse effects and mechanisms involved. To date, for the regulatory appraisal of metabolism-disrupting chemicals (MDCs), no harmonised guidance to assess the weight of evidence has been developed at the EU or international level. To explore how to develop this, we applied a formal Expert Knowledge Elicitation (EKE) approach within the European GOLIATH project. EKE captures expert judgment in a quantitative manner and provides an estimate of uncertainty of the final opinion. As a proof of principle, we selected one suspected MDC -triphenyl phosphate (TPP) - based on its related adverse endpoints (obesity/adipogenicity) relevant to metabolic disruption and a putative Molecular Initiating Event (MIE): activation of peroxisome proliferator activated receptor gamma (PPARγ). We conducted a systematic literature review and assessed the quality of the lines of evidence with two independent groups of experts within GOLIATH, with the objective of categorising the metabolic disruption properties of TPP, by applying an EKE approach. Having followed the entire process separately, both groups arrived at the same conclusion, designating TPP as a "suspected MDC" with an overall quantitative agreement exceeding 85%, indicating robust reproducibility. The EKE method provides to be an important way to bring together scientists with diverse expertise and is recommended for future work in this area.


Subject(s)
Endocrine Disruptors , Organophosphates , Animals , Humans , Endocrine Disruptors/toxicity , Expert Testimony , Organophosphates/toxicity , PPAR gamma/metabolism , PPAR gamma/agonists , Risk Assessment
4.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Article in English | MEDLINE | ID: mdl-34725151

ABSTRACT

Liver metastasis is a major cause of mortality for patients with colorectal cancer (CRC). Mismatch repair-proficient (pMMR) CRCs make up about 95% of metastatic CRCs, and are unresponsive to immune checkpoint blockade (ICB) therapy. Here we show that mouse models of orthotopic pMMR CRC liver metastasis accurately recapitulate the inefficacy of ICB therapy in patients, whereas the same pMMR CRC tumors are sensitive to ICB therapy when grown subcutaneously. To reveal local, nonmalignant components that determine CRC sensitivity to treatment, we compared the microenvironments of pMMR CRC cells grown as liver metastases and subcutaneous tumors. We found a paucity of both activated T cells and dendritic cells in ICB-treated orthotopic liver metastases, when compared with their subcutaneous tumor counterparts. Furthermore, treatment with Feline McDonough sarcoma (FMS)-like tyrosine kinase 3 ligand (Flt3L) plus ICB therapy increased dendritic cell infiltration into pMMR CRC liver metastases and improved mouse survival. Lastly, we show that human CRC liver metastases and microsatellite stable (MSS) primary CRC have a similar paucity of T cells and dendritic cells. These studies indicate that orthotopic tumor models, but not subcutaneous models, should be used to guide human clinical trials. Our findings also posit dendritic cells as antitumor components that can increase the efficacy of immunotherapies against pMMR CRC.


Subject(s)
Colorectal Neoplasms/drug therapy , Immune Checkpoint Inhibitors/therapeutic use , Liver Neoplasms, Experimental/drug therapy , Animals , Cell Line, Tumor , Colorectal Neoplasms/immunology , Colorectal Neoplasms/pathology , DNA Mismatch Repair , Dendritic Cells , Drug Screening Assays, Antitumor , Humans , Interferon-gamma/therapeutic use , Liver Neoplasms, Experimental/immunology , Liver Neoplasms, Experimental/secondary , Male , Mice, Inbred C57BL
5.
Chem Res Toxicol ; 36(1): 53-65, 2023 01 16.
Article in English | MEDLINE | ID: mdl-36534483

ABSTRACT

Receptor-mediated molecular initiating events (MIEs) and their relevance in endocrine activity (EA) have been highlighted in literature. More than 15 receptors have been associated with neurodevelopmental adversity and metabolic disruption. MIEs describe chemical interactions with defined biological outcomes, a relationship that could be described with quantitative structure-activity relationship (QSAR) models. QSAR uncertainty can be assessed using the conformal prediction (CP) framework, which provides similarity (i.e., nonconformity) scores relative to the defined classes per prediction. CP calibration can indirectly mitigate data imbalance during model development, and the nonconformity scores serve as intrinsic measures of chemical applicability domain assessment during screening. The focus of this work was to propose an in silico predictive strategy for EA. First, 23 QSAR models for MIEs associated with EA were developed using high-throughput data for 14 receptors. To handle the data imbalance, five protocols were compared, and CP provided the most balanced class definition. Second, the developed QSAR models were applied to a large data set (∼55,000 chemicals), comprising chemicals representative of potential risk for human exposure. Using CP, it was possible to assess the uncertainty of the screening results and identify model strengths and out of domain chemicals. Last, two clustering methods, t-distributed stochastic neighbor embedding and Tanimoto similarity, were used to identify compounds with potential EA using known endocrine disruptors as reference. The cluster overlap between methods produced 23 chemicals with suspected or demonstrated EA potential. The presented models could be utilized for first-tier screening and identification of compounds with potential biological activity across the studied MIEs.


Subject(s)
Endocrine Disruptors , Hazardous Substances , Humans , Hazardous Substances/toxicity , Quantitative Structure-Activity Relationship , Molecular Conformation , Endocrine Disruptors/toxicity
6.
Gut ; 71(1): 129-147, 2022 01.
Article in English | MEDLINE | ID: mdl-33568427

ABSTRACT

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignancy and lacks effective treatment. We aimed to understand molecular mechanisms of the intertwined interactions between tumour stromal components in metastasis and to provide a new paradigm for PDAC therapy. DESIGN: Two unselected cohorts of 154 and 20 patients with PDAC were subjected to correlation between interleukin (IL)-33 and CXCL3 levels and survivals. Unbiased expression profiling, and genetic and pharmacological gain-of-function and loss-of-function approaches were employed to identify molecular signalling in tumour-associated macrophages (TAMs) and myofibroblastic cancer-associated fibroblasts (myoCAFs). The role of the IL-33-ST2-CXCL3-CXCR2 axis in PDAC metastasis was evaluated in three clinically relevant mouse PDAC models. RESULTS: IL-33 was specifically elevated in human PDACs and positively correlated with tumour inflammation in human patients with PDAC. CXCL3 was highly upregulated in IL-33-stimulated macrophages that were the primary source of CXCL3. CXCL3 was correlated with poor survival in human patients with PDAC. Mechanistically, activation of the IL-33-ST2-MYC pathway attributed to high CXCL3 production. The highest level of CXCL3 was found in PDAC relative to other cancer types and its receptor CXCR2 was almost exclusively expressed in CAFs. Activation of CXCR2 by CXCL3 induced a CAF-to-myoCAF transition and α-smooth muscle actin (α-SMA) was uniquely upregulated by the CXCL3-CXCR2 signalling. Type III collagen was identified as the CXCL3-CXCR2-targeted adhesive molecule responsible for myoCAF-driven PDAC metastasis. CONCLUSIONS: Our work provides novel mechanistic insights into understanding PDAC metastasis by the TAM-CAF interaction and targeting each of these signalling components would provide an attractive and new paradigm for treating pancreatic cancer.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Carcinoma, Pancreatic Ductal/pathology , Chemokines, CXC/metabolism , Pancreatic Neoplasms/pathology , Tumor-Associated Macrophages/metabolism , Animals , Carcinoma, Pancreatic Ductal/mortality , Cohort Studies , Humans , Interleukin-33/metabolism , Mice, Knockout , Neoplasm Metastasis , Pancreatic Neoplasms/mortality , Up-Regulation
7.
Environ Sci Technol ; 56(14): 10216-10228, 2022 07 19.
Article in English | MEDLINE | ID: mdl-35797464

ABSTRACT

Bisphenol A (BPA) is an industrial chemical, which has raised human health and environmental concerns due to its endocrine-disrupting properties. BPA analogues are less well-studied despite their wide use in consumer products. These analogues have been detected in water and aquatic organisms around the world, with some analogues showing toxic effects in various species including fish. Here, we present novel organ-specific time-course distribution data of bisphenol Z (BPZ) in female zebrafish (Danio rerio), including concentrations in the ovaries, liver, and brain, a rarely sampled organ with high toxicological relevance. Furthermore, fish-specific in vitro biotransformation rates were determined for 11 selected bisphenols. A physiologically based toxicokinetic (PBTK) model was adapted for four of these bisphenols, which was able to predict levels in the gonads, liver, and brain as well as the whole body within a 2-5-fold error with respect to experimental data, covering several important target organs of toxicity. In particular, predicted liver concentrations improved compared to currently available PBTK models. Predicted data indicate that studied bisphenols mainly distribute to the carcass and gonads and less to the brain. Our model provides a tool to increase our understanding on the distribution and kinetics of a group of emerging pollutants.


Subject(s)
Water Pollutants, Chemical , Zebrafish , Animals , Benzhydryl Compounds/toxicity , Brain , Female , Humans , Liver/metabolism , Phenols , Toxicokinetics , Water Pollutants, Chemical/metabolism , Water Pollutants, Chemical/toxicity , Zebrafish/metabolism
8.
Environ Sci Technol ; 56(12): 8363-8372, 2022 06 21.
Article in English | MEDLINE | ID: mdl-35561338

ABSTRACT

Data on toxic effects are at large missing the prevailing understanding of the risks of industrial chemicals. Thyroid hormone (TH) system disruption includes interferences of the life cycle of the thyroid hormones and may occur in various organs. In the current study, high-throughput screening data available for 14 putative molecular initiating events of adverse outcome pathways, related to disruption of the TH system, were used to develop 19 in silico models for identification of potential thyroid hormone system-disrupting chemicals. The conformal prediction framework with the underlying Random Forest was used as a wrapper for the models allowing for setting the desired confidence level and controlling the error rate of predictions. The trained models were then applied to two different databases: (i) an in-house database comprising xenobiotics identified in human blood and ii) currently used chemicals registered in the Swedish Product Register, which have been predicted to have a high exposure index to consumers. The application of these models showed that among currently used chemicals, fewer were overall predicted as active compared to chemicals identified in human blood. Chemicals of specific concern for TH disruption were identified from both databases based on their predicted activity.


Subject(s)
Endocrine Disruptors , Computer Simulation , Endocrine Disruptors/toxicity , High-Throughput Screening Assays , Humans , Thyroid Hormones/metabolism , Xenobiotics
9.
J Am Chem Soc ; 143(9): 3416-3429, 2021 03 10.
Article in English | MEDLINE | ID: mdl-33626278

ABSTRACT

The extra hepatic delivery of antisense oligonucleotides (ASOs) remains a challenge and hampers the widespread application of this powerful class of therapeutic agents. In that regard, pancreatic beta cells are a particularly attractive but challenging cell type because of their pivotal role in diabetes and the fact that they are refractory to uptake of unconjugated ASOs. To circumvent this, we have expanded our understanding of the structure activity relationship of ASOs conjugated to Glucagon Like Peptide 1 Receptor (GLP1R) agonist peptide ligands. We demonstrate the key role of the linker chemistry and its optimization to design maleimide based conjugates with improved in vivo efficacy. In addition, truncation studies and scoping of a diverse set of GLP1R agonists proved fruitful to identify additional targeting ligands efficacious in vivo including native hGLP1(7-36)NH2. Variation of the carrier peptide also shed some light on the dramatic impact of subtle sequence differences on the corresponding ASO conjugate performance in vivo, an area which clearly warrant further investigations. We have confirmed the remarkable potential of GLP1R agonist conjugation for the delivery of ASOs to pancreatic beta cell by effectively knocking down islet amyloid polypeptide (IAPP) mRNA, a potential proapoptotic target, in mice.


Subject(s)
Drug Carriers/chemistry , Glucagon-Like Peptide-1 Receptor/chemistry , Insulin-Secreting Cells/drug effects , Oligonucleotides, Antisense/pharmacology , Peptides/chemistry , Amino Acid Sequence , Animals , Glucagon-Like Peptide-1 Receptor/agonists , HEK293 Cells , Humans , Islet Amyloid Polypeptide/genetics , Mice, Inbred C57BL , Molecular Structure , RNA, Messenger/metabolism , Structure-Activity Relationship
10.
Environ Sci Technol ; 55(2): 1088-1098, 2021 01 19.
Article in English | MEDLINE | ID: mdl-33381962

ABSTRACT

Transformation products ought to be an important consideration in chemical alternatives assessment. In this study, a recently established hazard ranking tool for alternatives assessment based on in silico data and multicriteria decision analysis (MCDA) methods was further developed to include chemical transformation products. Decabromodiphenyl ether (decaBDE) and five proposed alternatives were selected as case chemicals; biotic and abiotic transformation reactions were considered using five in silico tools. A workflow was developed to select transformation products with the highest occurrence potential. The most probable transformation products of the alternative chemicals were often similarly persistent but more mobile in aquatic environments, which implies an increasing exposure potential. When persistence (P), bioaccumulation (B), mobility in the aquatic environment (M), and toxicity (T) are considered (via PBT, PMT, or PBMT composite scoring), all six flame retardants have at least one transformation product that can be considered more hazardous, across diverse MCDA. Even when considering transformation products, the considered alternatives remain less hazardous than decaBDE, though the range of hazard of the five alternatives was reduced. The least hazardous of the considered alternatives were melamine and bis(2-ethylhexyl)-tetrabromophthalate. This developed tool could be integrated within holistic alternatives assessments considering use and life cycle impacts or additionally prioritizing transformation products within (bio)monitoring screening studies.


Subject(s)
Flame Retardants , Hazardous Substances , Computer Simulation
11.
Brain ; 143(3): 976-992, 2020 03 01.
Article in English | MEDLINE | ID: mdl-32091109

ABSTRACT

Research into hippocampal self-regulation abilities may help determine the clinical significance of hippocampal hyperactivity throughout the pathophysiological continuum of Alzheimer's disease. In this study, we aimed to identify the effects of amyloid-ß peptide 42 (amyloid-ß42) and phosphorylated tau on the patterns of functional connectomics involved in hippocampal downregulation. We identified 48 cognitively unimpaired participants (22 with elevated CSF amyloid-ß peptide 42 levels, 15 with elevated CSF phosphorylated tau levels, mean age of 62.705 ± 4.628 years), from the population-based 'Alzheimer's and Families' study, with baseline MRI, CSF biomarkers, APOE genotyping and neuropsychological evaluation. We developed a closed-loop, real-time functional MRI neurofeedback task with virtual reality and tailored it for training downregulation of hippocampal subfield cornu ammonis 1 (CA1). Neurofeedback performance score, cognitive reserve score, hippocampal volume, number of apolipoprotein ε4 alleles and sex were controlled for as confounds in all cross-sectional analyses. First, using voxel-wise multiple regression analysis and controlling for CSF biomarkers, we identified the effect of healthy ageing on eigenvector centrality, a measure of each voxel's overall influence based on iterative whole-brain connectomics, during hippocampal CA1 downregulation. Then, controlling for age, we identified the effects of abnormal CSF amyloid-ß42 and phosphorylated tau levels on eigenvector centrality during hippocampal CA1 downregulation. Across subjects, our main findings during hippocampal downregulation were: (i) in the absence of abnormal biomarkers, age correlated with eigenvector centrality negatively in the insula and midcingulate cortex, and positively in the inferior temporal gyrus; (ii) abnormal CSF amyloid-ß42 (<1098) correlated negatively with eigenvector centrality in the anterior cingulate cortex and primary motor cortex; and (iii) abnormal CSF phosphorylated tau levels (>19.2) correlated with eigenvector centrality positively in the ventral striatum, anterior cingulate and somatosensory cortex, and negatively in the precuneus and orbitofrontal cortex. During resting state functional MRI, similar eigenvector centrality patterns in the cingulate had previously been associated to CSF biomarkers in mild cognitive impairment and dementia patients. Using the developed closed-loop paradigm, we observed such patterns, which are characteristic of advanced disease stages, during a much earlier presymptomatic phase. In the absence of CSF biomarkers, our non-invasive, interactive, adaptive and gamified neuroimaging procedure may provide important information for clinical prognosis and monitoring of therapeutic efficacy. We have released the developed paradigm and analysis pipeline as open-source software to facilitate replication studies.


Subject(s)
Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/diagnostic imaging , Amyloid beta-Peptides/cerebrospinal fluid , CA1 Region, Hippocampal/metabolism , Neurofeedback/methods , Peptide Fragments/cerebrospinal fluid , tau Proteins/cerebrospinal fluid , Age Factors , Aged , Alzheimer Disease/complications , Apolipoprotein E4/genetics , Biomarkers/cerebrospinal fluid , Case-Control Studies , Cognitive Dysfunction/complications , Cognitive Dysfunction/metabolism , Connectome , Cross-Sectional Studies , Down-Regulation , Female , Genotype , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuroimaging , Neuropsychological Tests , Phosphorylation , Software , Virtual Reality
12.
Arch Toxicol ; 95(6): 2123-2136, 2021 06.
Article in English | MEDLINE | ID: mdl-33961089

ABSTRACT

Antisense oligonucleotides (ASOs) are a promising therapeutic modality. However, failure to predict acute kidney injury induced by SPC5001 ASO observed in a clinical trial suggests the need for additional preclinical models to complement the preceding animal toxicity studies. To explore the utility of in vitro systems in this space, we evaluated the induction of nephrotoxicity and kidney injury biomarkers by SPC5001 in human renal proximal tubule epithelial cells (HRPTEC), cultured in 2D, and in a recently developed kidney proximal tubule-on-a-chip. 2D HRPTEC cultures were exposed to the nephrotoxic ASO SPC5001 or the safe control ASO 556089 (0.16-40 µM) for up to 72 h, targeting PCSK9 and MALAT1, respectively. Both ASOs induced a concentration-dependent downregulation of their respective mRNA targets but cytotoxicity (determined by LDH activity) was not observed at any concentration. Next, chip-cultured HRPTEC were exposed to SPC5001 (0.5 and 5 µM) and 556089 (1 and 10 µM) for 48 h to confirm downregulation of their respective target transcripts, with 74.1 ± 5.2% for SPC5001 (5 µM) and 79.4 ± 0.8% for 556089 (10 µM). During extended exposure for up to 20 consecutive days, only SPC5001 induced cytotoxicity (at the higher concentration; 5 µM), as evaluated by LDH in the perfusate medium. Moreover, perfusate levels of biomarkers KIM-1, NGAL, clusterin, osteopontin and VEGF increased 2.5 ± 0.2-fold, 3.9 ± 0.9-fold, 2.3 ± 0.6-fold, 3.9 ± 1.7-fold and 1.9 ± 0.4-fold respectively, in response to SPC5001, generating distinct time-dependent profiles. In conclusion, target downregulation, cytotoxicity and kidney injury biomarkers were induced by the clinically nephrotoxic ASO SPC5001, demonstrating the translational potential of this kidney on-a-chip.


Subject(s)
Acute Kidney Injury/chemically induced , Kidney Tubules, Proximal/drug effects , Oligonucleotides, Antisense/toxicity , Oligonucleotides/toxicity , Acute Kidney Injury/pathology , Biomarkers/metabolism , Cells, Cultured , Dose-Response Relationship, Drug , Humans , Kidney Tubules, Proximal/pathology , L-Lactate Dehydrogenase/metabolism , Lab-On-A-Chip Devices , Oligonucleotides/administration & dosage , Oligonucleotides, Antisense/administration & dosage , RNA, Messenger/metabolism , Time Factors
13.
Toxicol Pathol ; 48(8): 981-993, 2020 12.
Article in English | MEDLINE | ID: mdl-33084520

ABSTRACT

Sensitive kidney safety assessment is important for successful drug development in both preclinical and clinical stages. The Food and Drug Administration recently qualified a composite measure of 6 urine creatinine-normalized biomarkers, such as clusterin, cystatin C, kidney injury molecule 1 (KIM-1), N-acetyl-ß-d-glucosaminidase, neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin, for monitoring kidney toxicity in early clinical trials. The qualification was based on small molecule drugs in humans, and the full panel has not been assessed in other species or for other drug modalities. This study evaluated the effects on these biomarkers for a constrained ethyl antisense oligonucleotide (tool ASO) with demonstrated kidney toxicity in mice compared to a control ASO of the same chemistry. Dosing 50 mg/kg of the tool ASO resulted in mild proximal tubular pathology and elevations in KIM-1, clusterin, NGAL, and cystatin C. A lower dose resulted in milder histopathology and lower biomarker increases. Unexpectedly, the control ASO induced mild elevations in KIM-1, NGAL, and cystatin C, despite the lack of pathology. Both KIM-1 and clusterin were most closely associated with kidney pathology and increased with the severity of injury. Altogether, our data suggest that a biomarker panel is a sensitive tool for the detection of preclinical ASO-induced kidney pathology.


Subject(s)
Acute Kidney Injury , Oligonucleotides, Antisense , Animals , Biomarkers , Kidney , Mice , Oligonucleotides, Antisense/toxicity , Urinalysis
14.
Environ Sci Technol ; 54(8): 4876-4885, 2020 04 21.
Article in English | MEDLINE | ID: mdl-32186175

ABSTRACT

Plastic materials contain various additives, which can be released during the entire lifespan of plastics and pose a threat to the environment and human health. Despite our knowledge on leakage of additives from products, accurate and rapid approaches to study emission kinetics are largely lacking, in particular, methodologies that can provide in-depth understanding of polymer/additive interactions. Here, we report on a novel approach using quartz crystal microbalance (QCM) to measure emissions of additives to water from polymer films spin-coated on quartz crystals. The methodology, being accurate and reproducible with a standard error of ±2.4%, was applied to a range of organophosphate esters (OPEs) and polymers with varying physicochemical properties. The release of most OPEs reached an apparent steady-state within 10 h. The release curves for the studied OPEs could be fitted using a Weibull model, which shows that the release is a two-phase process with an initial fast phase driven by partitioning of OPEs readily available at or close to the polymer film surface, and a slower phase dominated by diffusion in the polymer. The kinetics of the first emission phase was mainly correlated with the hydrophobicity of the OPEs, whereas the diffusion phase was weakly correlated with molecular size. The developed QCM-based method for assessing and studying release of organic chemicals from a polymeric matrix is well suited for rapid screening of additives in efforts to identify more sustainable replacement polymer additives with lower emission potential.


Subject(s)
Polymers , Quartz Crystal Microbalance Techniques , Esters , Humans , Organophosphates , Quartz , Water
15.
Int J Mol Sci ; 21(10)2020 May 14.
Article in English | MEDLINE | ID: mdl-32423144

ABSTRACT

The purpose of this project report is to introduce the European "GOLIATH" project, a new research project which addresses one of the most urgent regulatory needs in the testing of endocrine-disrupting chemicals (EDCs), namely the lack of methods for testing EDCs that disrupt metabolism and metabolic functions. These chemicals collectively referred to as "metabolism disrupting compounds" (MDCs) are natural and anthropogenic chemicals that can promote metabolic changes that can ultimately result in obesity, diabetes, and/or fatty liver in humans. This project report introduces the main approaches of the project and provides a focused review of the evidence of metabolic disruption for selected EDCs. GOLIATH will generate the world's first integrated approach to testing and assessment (IATA) specifically tailored to MDCs. GOLIATH will focus on the main cellular targets of metabolic disruption-hepatocytes, pancreatic endocrine cells, myocytes and adipocytes-and using an adverse outcome pathway (AOP) framework will provide key information on MDC-related mode of action by incorporating multi-omic analyses and translating results from in silico, in vitro, and in vivo models and assays to adverse metabolic health outcomes in humans at real-life exposures. Given the importance of international acceptance of the developed test methods for regulatory use, GOLIATH will link with ongoing initiatives of the Organisation for Economic Development (OECD) for test method (pre-)validation, IATA, and AOP development.


Subject(s)
Diabetes Mellitus/epidemiology , Endocrine Disruptors/adverse effects , Fatty Liver/epidemiology , Obesity/epidemiology , Adipocytes/drug effects , Adipocytes/pathology , Diabetes Mellitus/chemically induced , Diabetes Mellitus/prevention & control , Fatty Liver/chemically induced , Fatty Liver/prevention & control , Humans , Metabolic Networks and Pathways/drug effects , Obesity/chemically induced , Obesity/prevention & control , Risk Assessment
16.
Int J Mol Sci ; 21(11)2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32492937

ABSTRACT

Ubiquitous exposure to endocrine-disrupting chemicals (EDCs) has caused serious concerns about the ability of these chemicals to affect neurodevelopment, among others. Since endocrine disruption (ED)-induced developmental neurotoxicity (DNT) is hardly covered by the chemical testing tools that are currently in regulatory use, the Horizon 2020 research and innovation action ENDpoiNTs has been launched to fill the scientific and methodological gaps related to the assessment of this type of chemical toxicity. The ENDpoiNTs project will generate new knowledge about ED-induced DNT and aims to develop and improve in vitro, in vivo, and in silico models pertaining to ED-linked DNT outcomes for chemical testing. This will be achieved by establishing correlative and causal links between known and novel neurodevelopmental endpoints and endocrine pathways through integration of molecular, cellular, and organismal data from in vitro and in vivo models. Based on this knowledge, the project aims to provide adverse outcome pathways (AOPs) for ED-induced DNT and to develop and integrate new testing tools with high relevance for human health into European and international regulatory frameworks.


Subject(s)
Endocrine Disruptors/toxicity , Environmental Monitoring/standards , Nervous System/drug effects , Toxicity Tests/standards , Animals , Endocrine System/drug effects , Environmental Exposure/adverse effects , Guidelines as Topic , Humans , Mice , Neurons/metabolism , Rats , Risk Assessment , Transcriptome
17.
Neuroimage ; 200: 332-343, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31247298

ABSTRACT

Visual imagery has been suggested to recruit occipital cortex via feedback projections from fronto-parietal regions, suggesting that these feedback projections might be exploited to boost recruitment of occipital cortex by means of real-time neurofeedback. To test this prediction, we instructed a group of healthy participants to perform peripheral visual imagery while they received real-time auditory feedback based on the BOLD signal from either early visual cortex or the medial superior parietal lobe. We examined the amplitude and temporal aspects of the BOLD response in the two regions. Moreover, we compared the impact of self-rated mental focus and vividness of visual imagery on the BOLD responses in these two areas. We found that both early visual cortex and the medial superior parietal cortex are susceptible to auditory neurofeedback within a single feedback session per region. However, the signal in parietal cortex was sustained for a longer time compared to the signal in occipital cortex. Moreover, the BOLD signal in the medial superior parietal lobe was more affected by focus and vividness of the visual imagery than early visual cortex. Our results thus demonstrate that (a) participants can learn to self-regulate the BOLD signal in early visual and parietal cortex within a single session, (b) that different nodes in the visual imagery network respond differently to neurofeedback, and that (c) responses in parietal, but not in occipital cortex are susceptible to self-rated vividness of mental imagery. Together, these results suggest that medial superior parietal cortex might be a suitable candidate to provide real-time feedback to patients suffering from visual field defects.


Subject(s)
Functional Neuroimaging/methods , Imagination/physiology , Nerve Net/physiology , Neurofeedback/physiology , Occipital Lobe/physiology , Parietal Lobe/physiology , Pattern Recognition, Visual/physiology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Young Adult
18.
Environ Sci Technol ; 53(11): 6341-6351, 2019 06 04.
Article in English | MEDLINE | ID: mdl-31081616

ABSTRACT

Alternatives assessment is applied for minimizing the risk of unintentionally replacing a hazardous chemical with another hazardous chemical. Central challenges are the diversity of properties to consider and the lack of high-quality experimental data. To address this, a novel alternatives assessment procedure was developed based on in silico data and multicriteria decision analysis (MCDA) methods. As a case study, 16 alternatives to the flame retardant decabromodiphenyl ether were considered. The hazard properties included persistence (P), bioaccumulation potential (B), toxicities (T), and mobility in water (M). Databases were consulted and 2866 experimental data points were collected for the target chemicals; however, these were mostly replicate data points for some hazard criteria for a subset of alternatives. Therefore, in silico data and three MCDA strategies were tested including heat mapping, multiattribute utility theory (MAUT), and Elimination Et Choix Traduisant la REalité (ELECTRE III). The heat map clearly showed that none of the target chemicals are hazard-free, whereas MAUT and ELECTRE III agreed on ranking the "least worst" choices. This study identified several challenges and the complexity in the alternatives assessment processes motivating more case studies combining in silico and MCDA approaches.


Subject(s)
Flame Retardants , Hazardous Substances , Decision Support Techniques , Halogenated Diphenyl Ethers , Risk Assessment
19.
J Environ Manage ; 246: 920-928, 2019 Sep 15.
Article in English | MEDLINE | ID: mdl-31279249

ABSTRACT

A bench-scale column experiment was performed to study the removal of 31 selected organic micropollutants (MPs) and phosphorus by lignite, xyloid lignite (Xylit), granular activated carbon (GAC), Polonite® and sand over a period of 12 weeks. In total 29 out of the 31 MPs showed removal efficiency >90% by GAC with an average removal of 97 ±â€¯6%. Xylit and lignite were less efficient with an average removal of 80 ±â€¯28% and 68 ±â€¯29%, respectively. The removal efficiency was found to be impacted by the characterization of the sorbents and physicochemical properties of the compounds, as well as the interaction between the sorbents and compounds. For instance, Xylit and lignite performed well for relatively hydrophobic (log octanol/water partition coefficient (Kow) ≥3) MPs, while the removal efficiency of moderately hydrophilic, highly hydrophilic and negatively charged MPs were lower. The organic sorbents were found to have more functional groups at their surfaces, which might explain the higher adsorption of MPs to these sorbents. The removal of several MPs improved after four weeks in sand, Xylit, GAC and lignite which may be related to increased biological activity and biofilm development. GAC and sand had limited ability to remove phosphorus (12 ±â€¯27% and 14 ±â€¯2%, respectively), while the calcium-silicate material Polonite® precipitated phosphorus efficiently and increased the total phosphorus removal from 12% to 96% after the GAC filter.


Subject(s)
Water Pollutants, Chemical , Water Purification , Adsorption , Charcoal , Phosphorus , Waste Disposal, Fluid , Wastewater
20.
Hum Brain Mapp ; 39(3): 1313-1326, 2018 03.
Article in English | MEDLINE | ID: mdl-29235185

ABSTRACT

Object recognition benefits maximally from multimodal sensory input when stimulus presentation is noisy, or degraded. Whether this advantage can be attributed specifically to the extent of overlap in object-related information, or rather, to object-unspecific enhancement due to the mere presence of additional sensory stimulation, remains unclear. Further, the cortical processing differences driving increased multisensory integration (MSI) for degraded compared with clear information remain poorly understood. Here, two consecutive studies first compared behavioral benefits of audio-visual overlap of object-related information, relative to conditions where one channel carried information and the other carried noise. A hierarchical drift diffusion model indicated performance enhancement when auditory and visual object-related information was simultaneously present for degraded stimuli. A subsequent fMRI study revealed visual dominance on a behavioral and neural level for clear stimuli, while degraded stimulus processing was mainly characterized by activation of a frontoparietal multisensory network, including IPS. Connectivity analyses indicated that integration of degraded object-related information relied on IPS input, whereas clear stimuli were integrated through direct information exchange between visual and auditory sensory cortices. These results indicate that the inverse effectiveness observed for identification of degraded relative to clear objects in behavior and brain activation might be facilitated by selective recruitment of an executive cortical network which uses IPS as a relay mediating crossmodal sensory information exchange.


Subject(s)
Auditory Perception/physiology , Parietal Lobe/physiology , Recognition, Psychology/physiology , Visual Perception/physiology , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Parietal Lobe/diagnostic imaging
SELECTION OF CITATIONS
SEARCH DETAIL