NaviCenta - The disease map for placental research.

The placenta remains the key organ to pregnancy complications, such as preeclampsia, contrarily the pathophysiology underlying the placental dysfunctions remains elusive. Here, we present our Disease Map "NaviCenta", which is an online resource based on the interactions between tissues, cellular compartments, and molecules that mediate disease-related processes in the placenta. We built cellular and molecular interaction networks based upon manual curation and annotation of publicly available information in the scientific literature, pathways resources, and Omics data. NaviCenta (Navigate the plaCenta) serves as an open access, spatio-temporal, multi-scale knowledge base, and analytical tool for enhanced interpretation and hypothesis testing on various placental disease phenotypes.

Ten Topics to Get Started in Medical Informatics Research.

The vast and heterogeneous data being constantly generated in clinics can provide great wealth for patients and research alike. The quickly evolving field of medical informatics research has contributed numerous concepts, algorithms, and standards to facilitate this development. However, these difficult relationships, complex terminologies, and multiple implementations can present obstacles for people who want to get active in the field. With a particular focus on medical informatics research conducted in Germany, we present in our Viewpoint a set of 10 important topics to improve the overall interdisciplinary communication between different stakeholders (eg, physicians, computational experts, experimentalists, students, patient representatives). This may lower the barriers to entry and offer a starting point for collaborations at different levels. The suggested topics are briefly introduced, then general best practice guidance is given, and further resources for in-depth reading or hands-on tutorials are recommended. In addition, the topics are set to cover current aspects and open research gaps of the medical informatics domain, including data regulations and concepts; data harmonization and processing; and data evaluation, visualization, and dissemination. In addition, we give an example on how these topics can be integrated in a medical informatics curriculum for higher education. By recognizing these topics, readers will be able to (1) set clinical and research data into the context of medical informatics, understanding what is possible to achieve with data or how data should be handled in terms of data privacy and storage; (2) distinguish current interoperability standards and obtain first insights into the processes leading to effective data transfer and analysis; and (3) value the use of newly developed technical approaches to utilize the full potential of clinical data.

A proteomic profile of the healthy human placenta.

BACKGROUND: The placenta remains one of the least studied organs within the human body. Yet, placental dysfunction has been associated with various pregnancy complications leading to both maternal and fetal death and long-term health consequences. The aim of this study was to characterise the protein networks of healthy term placental sub-anatomical regions using label free quantification mass spectrometry. METHODS: Three healthy placentae were sampled at five sample sites and each biopsy was dissected into maternal-, middle-, and fetal- sub-anatomical regions. Quadrupole-orbitrap mass spectrometer was used in data dependant analysis mode to identify 1859 unique proteins before detailed differential expression between regions. RESULTS: Protein profiling identified 1081, 1086, and 1101 proteins in maternal, middle, and fetal sub-anatomical regions respectively. Differentially expressed proteins were identified considering the effect between sample site location and sub-anatomical region on protein expression. Of these, 374 differentially expressed proteins (Two-way ANOVA adjusted p-value < 0.05, HSD Tukey adjusted p-value 0.05) were identified between sample site locations and sub-anatomical regions. The placenta specific disease map NaviCenta ( https://www.sbi.uni-rostock.de/minerva/index.xhtml?id=NaviCenta ) was used to focus functional analysis results to the placenta specific context. Subsequently, functional analysis with a focus on senescence, and mitochondrial function were performed. Significant differences were observed between sub-anatomical regions in protein intensity and composition. A decrease in anti-senescent proteins within the maternal sub-anatomical region, and an increase in proteins associated with a switch from ATP to fatty acid consumption as a source of energy between middle and fetal sub-anatomical regions were observed. CONCLUSION: These results suggest that normal proteomic variations exist within the anatomical structure of the placenta, thus recommending serial sectioning methodology for consistent placental research.

Single extracellular vesicle analysis in human amniotic fluid shows evidence of phenotype alterations in preeclampsia.

Amniotic fluid surrounding the developing fetus is a complex biological fluid rich in metabolically active bio-factors. The presence of extracellular vesicles (EVs) in amniotic fluid has been mainly related to foetal urine. We here characterized EVs from term amniotic fluid in terms of surface marker expression using different orthogonal techniques. EVs appeared to be a heterogeneous population expressing markers of renal, placental, epithelial and stem cells. Moreover, we compared amniotic fluid EVs from normal pregnancies with those of preeclampsia, a hypertensive disorder affecting up to 8% of pregnancies worldwide. An increase of CD105 (endoglin) expressing EVs was observed in preeclamptic amniotic fluid by bead-based cytofluorimetric analysis, and further confirmed using a chip-based analysis. HLA-G, a typical placental marker, was not co-expressed by the majority of CD105+ EVs, in analogy with amniotic fluid stromal cell derived-EVs. At a functional level, preeclampsia-derived EVs, but not normal pregnancy EVs, showed an antiangiogenic effect, possibly due to the decoy effect of endoglin. Our results provide a characterization of term amniotic fluid-EVs, supporting their origin from foetal and placental cells. In preeclampsia, the observed antiangiogenic characteristics of amniotic fluid-EVs may reflect the hypoxic and antiangiogenic microenvironment and could possibly impact on the developing fetus or on the surrounding foetal membranes.

Computational Models on Pathological Redox Signalling Driven by Pregnancy: A Review.

Oxidative stress is associated with a myriad of diseases including pregnancy pathologies with long-term cardiovascular repercussions for both the mother and baby. Aberrant redox signalling coupled with deficient antioxidant defence leads to chronic molecular impairment. Abnormal placentation has been considered the primary source for reactive species; however, placental dysfunction has been deemed secondary to maternal cardiovascular maladaptation in pregnancy. While various therapeutic interventions, aimed at combating deregulated oxidative stress during pregnancy have shown promise in experimental models, they often result as inconclusive or detrimental in clinical trials, warranting the need for further research to identify candidates. The strengths and limitations of current experimental methods in redox research are discussed. Assessment of redox status and oxidative stress in experimental models and in clinical practice remains challenging; the state-of-the-art of computational models in this field is presented in this review, comparing static and dynamic models which provide functional information such as protein-protein interactions, as well as the impact of changes in molecular species on the redox-status of the system, respectively. Enhanced knowledge of redox biology in during pregnancy through computational modelling such as generation of Systems Biology Markup Language model which integrates existing models to a larger network in the context of placenta physiology.

COVID19 Disease Map, a computational knowledge repository of virus-host interaction mechanisms.

We need to effectively combine the knowledge from surging literature with complex datasets to propose mechanistic models of SARS-CoV-2 infection, improving data interpretation and predicting key targets of intervention. Here, we describe a large-scale community effort to build an open access, interoperable and computable repository of COVID-19 molecular mechanisms. The COVID-19 Disease Map (C19DMap) is a graphical, interactive representation of disease-relevant molecular mechanisms linking many knowledge sources. Notably, it is a computational resource for graph-based analyses and disease modelling. To this end, we established a framework of tools, platforms and guidelines necessary for a multifaceted community of biocurators, domain experts, bioinformaticians and computational biologists. The diagrams of the C19DMap, curated from the literature, are integrated with relevant interaction and text mining databases. We demonstrate the application of network analysis and modelling approaches by concrete examples to highlight new testable hypotheses. This framework helps to find signatures of SARS-CoV-2 predisposition, treatment response or prioritisation of drug candidates. Such an approach may help deal with new waves of COVID-19 or similar pandemics in the long-term perspective.

Placental mitochondrial function as a driver of angiogenesis and placental dysfunction.

The placenta is a highly vascularized and complex foetal organ that performs various tasks, crucial to a healthy pregnancy. Its dysfunction leads to complications such as stillbirth, preeclampsia, and intrauterine growth restriction. The specific cause of placental dysfunction remains unknown. Recently, the role of mitochondrial function and mitochondrial adaptations in the context of angiogenesis and placental dysfunction is getting more attention. The required energy for placental remodelling, nutrient transport, hormone synthesis, and the reactive oxygen species leads to oxidative stress, stemming from mitochondria. Mitochondria adapt to environmental changes and have been shown to adjust their oxygen and nutrient use to best support placental angiogenesis and foetal development. Angiogenesis is the process by which blood vessels form and is essential for the delivery of nutrients to the body. This process is regulated by different factors, pro-angiogenic factors and anti-angiogenic factors, such as sFlt-1. Increased circulating sFlt-1 levels have been linked to different preeclamptic phenotypes. One of many effects of increased sFlt-1 levels, is the dysregulation of mitochondrial function. This review covers mitochondrial adaptations during placentation, the importance of the anti-angiogenic factor sFlt-1in placental dysfunction and its role in the dysregulation of mitochondrial function.

Overexpression of microRNAs miR-25-3p, miR-185-5p and miR-132-3p in Late Onset Fetal Growth Restriction, Validation of Results and Study of the Biochemical Pathways Involved.

In a prospective study, 48 fetuses were evaluated with Doppler ultrasound after 34 weeks and classified, according to the cerebroplacental ratio (CPR) and estimated fetal weight (EFW), into fetuses with normal growth and fetuses with late-onset fetal growth restriction (LO-FGR). Overexpression of miRNAs from neonatal cord blood belonging to LO-FGR fetuses, was validated by real-time PCR. In addition, functional characterization of overexpressed miRNAs was performed by analyzing overrepresented pathways, gene ontologies, and prioritization of synergistically working miRNAs. Three miRNAs: miR-25-3p, miR-185-5p and miR-132-3p, were significantly overexpressed in cord blood of LO-FGR fetuses. Pathway and gene ontology analysis revealed over-representation of certain molecular pathways associated with cardiac development and neuron death. In addition, prioritization of synergistically working miRNAs highlighted the importance of miR-185-5p and miR-25-3p in cholesterol efflux and starvation responses associated with LO-FGR phenotypes. Evaluation of miR-25-3p; miR-132-3p and miR-185-5p might serve as molecular biomarkers for the diagnosis and management of LO-FGR; improving the understanding of its influence on adult disease.

TGF-ß1 Induces Changes in the Energy Metabolism of White Adipose Tissue-Derived Human Adult Mesenchymal Stem/Stromal Cells In Vitro.

Adipose tissue plays an active role in the regulation of the body´s energy balance. Mesenchymal stem/stromal cells from adipose tissue (adMSC) are the precursor cells for repair and adipogenesis. Since the balance of the differentiation state of adipose tissue-resident cells is associated with the development of various diseases, the examination of the regulation of proliferation and differentiation of adMSC might provide new therapeutic targets. Transforming growth factor-ß1 (TGF-ß1) is synthetized by many cell types and is involved in various biological processes. Here, we investigated the effects of different concentrations of TGF-ß1 (1-10 ng/mL) on adMSC proliferation, metabolic activity, and analyzed the gene expression data obtained from DNA microarrays by bioinformatics. TGF-ß1 induced the concentration- and time-dependent increase in the cell number of adMSC with simultaneously unchanged cell cycle distributions. The basal oxygen consumption rates did not change significantly after TGF-ß1 exposure. However, glycolytic activity was significantly increased. The gene expression analysis identified 3275 differentially expressed genes upon exposure to TGF-ß1. According to the pathway enrichment analyses, they also included genes associated with energy metabolism. Thus, it was shown that TGF-ß1 induces changes in the energy metabolism of adMSC. Whether these effects are of relevance invivo and whether they contribute to pathogenesis should be addressed in further examinations.

A methodology for the assessment of inhalation exposure to aluminium from antiperspirant sprays.

Inhalative exposure can occur accidentally when using cosmetic spray products. Usually, a tiered approach is applied for exposure assessment, starting with rather conservative, simplistic calculation models that may be improved with measured data and more refined modelling. Here we report on an advanced methodology to mimic in-use conditions for antiperspirant spray products to provide a more accurate estimate of the amount of aluminium possibly inhaled and taken up systemically, thus contributing to the overall body burden. Four typical products were sprayed onto a skin surrogate in defined rooms. For aluminium, size-related aerosol release fractions, i.e. inhalable, thoracic and respirable, were determined by a mass balance method taking droplet maturation into account. These data were included into a simple two-box exposure model, allowing calculation of the inhaled aluminium dose over 12 min. Systemic exposure doses were calculated for exposure of the deep lung and the upper respiratory tract using the Multiple Path Particle Deposition Model (MPPD) model. The total systemically available dose of aluminium was in all cases found to be less than 0.5 µg per application. With this study it could be demonstrated that refinement of the input data of the two-box exposure model with measured data of released airborne aluminium is a valuable approach to analyse the contribution of antiperspirant spray inhalation to total aluminium exposure as part of the overall risk assessment. We suggest the methodology which can also be applied to other exposure modelling approaches for spray products, and further is adapted to other similar use scenarios.

Use of human in vitro skin models for accurate and ethical risk assessment: metabolic considerations.

Several human skin models employing primary cells and immortalized cell lines used as monocultures or combined to produce reconstituted 3D skin constructs have been developed. Furthermore, these models have been included in European genotoxicity and sensitization/irritation assay validation projects. In order to help interpret data, Cosmetics Europe (formerly COLIPA) facilitated research projects that measured a variety of defined phase I and II enzyme activities and created a complete proteomic profile of xenobiotic metabolizing enzymes (XMEs) in native human skin and compared them with data obtained from a number of in vitro models of human skin. Here, we have summarized our findings on the current knowledge of the metabolic capacity of native human skin and in vitro models and made an overall assessment of the metabolic capacity from gene expression, proteomic expression, and substrate metabolism data. The known low expression and function of phase I enzymes in native whole skin were reflected in the in vitro models. Some XMEs in whole skin were not detected in in vitro models and vice versa, and some major hepatic XMEs such as cytochrome P450-monooxygenases were absent or measured only at very low levels in the skin. Conversely, despite varying mRNA and protein levels of phase II enzymes, functional activity of glutathione S-transferases, N-acetyltransferase 1, and UDP-glucuronosyltransferases were all readily measurable in whole skin and in vitro skin models at activity levels similar to those measured in the liver. These projects have enabled a better understanding of the contribution of XMEs to toxicity endpoints.

Risk assessment of amorphous silicon dioxide nanoparticles in a glass cleaner formulation.

Since nanomaterials are a heterogeneous group of substances used in various applications, risk assessment needs to be done on a case-by-case basis. Here the authors assess the risk (hazard and exposure) of a glass cleaner with synthetic amorphous silicon dioxide (SAS) nanoparticles during production and consumer use (spray application). As the colloidal material used is similar to previously investigated SAS, the hazard profile was considered to be comparable. Overall, SAS has a low toxicity. Worker exposure was analysed to be well controlled. The particle size distribution indicated that the aerosol droplets were in a size range not expected to reach the alveoli. Predictive modelling was used to approximate external exposure concentrations. Consumer and environmental exposure were estimated conservatively and were not of concern. It was concluded based on the available weight-of-evidence that the production and application of the glass cleaner is safe for humans and the environment under intended use conditions.

Investigation of the skin sensitizing properties of 5 osmolytic prodrugs in a weight-of-evidence assessment, employing in silico, in vivo, and read across analyses.

The amino acid esters ethyl glycinate (EG), DL-α-tocopheryl-(mono-)betainate hydrochloride (TMB), DL-α-tocopheryl-(mono-)glycinate hydrochloride (TMG), DL-α-tocopheryl-(mono-)prolinate hydrochloride (TMP), and DL-α-tocopheryl-(mono-)sarcosinate hydrochloride (TMS) were previously shown to exert an osmoprotective function to human skin in vitro. Based on literature data, the parent compounds α-tocopherol (vitamin E) and the amino acids glycine, betaine (trimethylated glycine), proline, and sarcosine (N-methylated glycine) are not considered to be sensitizers. To investigate skin sensitizing properties of the esters, EG, TMG, and TMP were tested in the Local Lymph Node Assay (LLNA). Remaining esters were assessed by read across analysis considering structural similarities and mechanistic aspects. The LLNA results were consistent with in silico outcomes from ToxTree 2.5.0 indicative for protein binding; EG was negative; TMG and TMP were positive. Since TMB and TMS showed structural similarities to TMG and TMP and were also positive in ToxTree, it was concluded that both TMB and TMS can also be expected to have a skin sensitizing potential and therefore animal testing was waived.

Optimised testing strategies for skin sensitization--the LLNA and beyond.

As toxicology in the 21st century progresses towards a future which aims at avoiding the use of in vivo testing, the endpoint of skin sensitisation can now be found in the front line. Accordingly, it was appropriate for several industry sectors to meet and review what has been learned from the currently most widely used in vivo method, the local lymph node assay (LLNA), and to consider the status of progress as we attempt to move beyond that test. No toxicology test is perfect, an experience brought into focus by issues of false positives and, to a lesser extent, false negatives in the LLNA. Use of weight of evidence arguments for classification and labelling, as well as for risk assessment was emphasised and it was also noted that a sufficient body of evidence now exists for conduct of methods other than the LLNA for carefully defined chemical classes. In terms of in vitro alternatives, progress towards methods which will deliver mainly hazard identification is being made, with some entering the final stages of validation, whereby (Q)SAR tools still need improvement to be used on a large scale in practise. As various other challenges also remain, e.g. testing lipophilic substances, as well as the development of non-animal methods which deliver reliable information on potency for risk assessment, these will remain a topic for continuing research and development.

Applicability and robustness of the hen's egg test for analysis of micronucleus induction (HET-MN): results from an inter-laboratory trial.

The hen's egg test for analysis of micronucleus formation (HET-MN) was developed several years ago to provide an alternative test system to the in vivo micronucleus test. In order to assess its applicability and robustness, a study was carried out at the University of Osnabrueck (lab A) and at the laboratories of Henkel AG & Co. KGaA (lab B). Following transfer of the method to lab B, a range of test substances that had been pre-tested at lab A, were tested at Henkel: the genotoxins cyclophosphamide, dimethylbenz(a)anthracene, methotrexate, acrylamide, azorubin, N-nitroso-dimethylamine and the non-genotoxins, orange G and isopropyl myristate. In a second phase, additional compounds with known in vivo properties were examined in both labs: the non-genotoxin, ampicillin, the "irrelevant" positives, isophorone and 2,4-dichlorophenol ("irrelevant" means positive in standard in vitro tests, but negative in vivo), the clastogen p-chloroaniline, and the aneugens carbendazim and vinorelbine. All substances were correctly predicted in both labs with respect to their in vivo genotoxic properties, indicating that the HET-MN may have an improved predictivity compared with current standard in vitro test systems. The results support the promising role of the HET-MN assay as a supplement to existing test batteries.

Guiding principles for the implementation of non-animal safety assessment approaches for cosmetics: skin sensitisation.

Characterisation of skin sensitisation potential is a key endpoint for the safety assessment of cosmetic ingredients especially when significant dermal exposure to an ingredient is expected. At present the mouse local lymph node assay (LLNA) remains the 'gold standard' test method for this purpose however non-animal test methods are under development that aim to replace the need for new animal test data. COLIPA (the European Cosmetics Association) funds an extensive programme of skin sensitisation research, method development and method evaluation and helped coordinate the early evaluation of the three test methods currently undergoing pre-validation. In May 2010, a COLIPA scientific meeting was held to analyse to what extent skin sensitisation safety assessments for cosmetic ingredients can be made in the absence of animal data. In order to propose guiding principles for the application and further development of non-animal safety assessment strategies it was evaluated how and when non-animal test methods, predictions based on physico-chemical properties (including in silico tools), threshold concepts and weight-of-evidence based hazard characterisation could be used to enable safety decisions. Generation and assessment of potency information from alternative tools which at present is predominantly derived from the LLNA is considered the future key research area.

Classification and labeling of industrial products with extreme pH by making use of in vitro methods for the assessment of skin and eye irritation and corrosion in a weight of evidence approach.

Classification and labeling of products with extreme pH values (≤ 2 or ≥ 11.5) is addressed in chemicals legislation. Following determination of pH and alkaline/acid reserve, additional in vitro tests are needed, especially to substantiate results less than corrosive. However, only limited experience with the practical application of in vitro methods to determine appropriate classifications for pH extreme products is available so far. Expert judgment and weight of evidence are given major roles under the globally harmonized system of classification and labeling of chemicals (GHS) and should be performed on a sound data basis. We have used a tiered testing strategy to assess 20 industrial products (cleaning and metal pretreatment) regarding their corrosive and irritating properties towards human skin models in vitro in the EpiDerm skin corrosion and/or skin irritation test. Nine dilutions of individual compounds were additionally tested. Non-corrosive samples were tested in the Hen's egg test chorioallantoic membrane (HET-CAM). We demonstrate how data is combined in a weight of evidence expert judgment, and give examples of classification decisions. To our knowledge this is the first comprehensive analysis of industrial products with extreme pH values to determine irritating and corrosive properties by making use of in vitro methods in a weight of evidence approach.

Eye irritation potential: usefulness of the HET-CAM under the Globally Harmonized System of classification and labeling of chemicals (GHS).

Extensive research has been conducted over the past decades to develop alternatives to the rabbit eye irritation test (Draize test) used in a regulatory context to assess eye irritation potentials. Although no single in vitro test has emerged as being completely acceptable for full replacement, various tests are considered to be suitable and are regularly used to assess certain aspects. Amongst these, the Hen's Egg Test Chorioallantoic Membrane (HET-CAM) has gained regulatory acceptance in various countries to classify severe eye irritants. In this retrospective study, historical eye irritation data (in vivo and in vitro) from 137 samples (approx. 75% non-irritants; 25% (severe) irritants) tested both in the HET-CAM and Draize eye test was compared with regard to the predicted eye irritation classes under the GHS and the traditional EU classification system (DSD).The overall concordance was in the range of 80-90%. A high specificity (96-98%, depending on the classification system and the chosen discrimination) but rather low sensitivity (48-65%) was observed. The study indicates that HET-CAM results are useful as part of weight-of-evidence assessments or in tiered approaches to assess eye irritation potentials rather than as stand-alone classification method.

Integrated risk assessment of a hydroxyapatite-protein-composite for use in oral care products: a weight-of-evidence case study.

Risk assessment of cosmetic ingredients represents a regulatory standard requirement in Europe and other regions. An integrated approach was designed to assess the safety of HPC, a particulate composite of hydroxyapatite and protein (gelatin) for use in oral care products, employing a weight-of-evidence assessment and considering specific physico-chemical properties and exposure conditions. An initial evaluation of the constituents suggested that their chemical nature does not represent a particular health hazard per se. Hydroxyapatite is the main component of teeth and bones in mammals; gelatin is used in food and assumed to be safe once a BSE/TSE risk has been excluded. In vitro screening tests were chosen to further evaluate the biocompatibility: Hen's egg test-chorioallantoic membrane (HET-CAM) to assess irritating effects towards mucous membranes; MTT cytotoxicity test with 3T3 fibroblasts; human corneal epithelial models to investigate inflammatory mediators and cytotoxicity; macrophage assays to measure cytotoxicity, inflammatory mediators and oxidative stress. Together with results from clinical studies, exposure estimates and analyses of kinetic properties, the presented information provides sound evidence to support the safe use of HPC. This is an example of a risk assessment for cosmetic use of small particles without the need for additional animal studies.