In vitro competition between two transmissible cancers and potential implications for their host, the Tasmanian devil.

Since the emergence of a transmissible cancer, devil facial tumour disease (DFT1), in the 1980s, wild Tasmanian devil populations have been in decline. In 2016, a second, independently evolved transmissible cancer (DFT2) was discovered raising concerns for survival of the host species. Here, we applied experimental and modelling frameworks to examine competition dynamics between the two transmissible cancers in vitro. Using representative cell lines for DFT1 and DFT2, we have found that in monoculture, DFT2 grows twice as fast as DFT1 but reaches lower maximum cell densities. Using co-cultures, we demonstrate that DFT2 outcompetes DFT1: the number of DFT1 cells decreasing over time, never reaching exponential growth. This phenomenon could not be replicated when cells were grown separated by a semi-permeable membrane, consistent with exertion of mechanical stress on DFT1 cells by DFT2. A logistic model and a Lotka-Volterra competition model were used to interrogate monoculture and co-culture growth curves, respectively, suggesting DFT2 is a better competitor than DFT1, but also showing that competition outcomes might depend on the initial number of cells, at least in the laboratory. We provide theories how the in vitro results could be translated to observations in the wild and propose that these results may indicate that although DFT2 is currently in a smaller geographic area than DFT1, it could have the potential to outcompete DFT1. Furthermore, we provide a framework for improving the parameterization of epidemiological models applied to these cancer lineages, which will inform future disease management.

High-resolution mass spectrometry identifies delayed biomarkers for improved precision in acetaminophen/paracetamol human biomonitoring.

Paracetamol/acetaminophen (N-acetyl-p-aminophenol, APAP) is a top selling analgesic used in more than 600 prescription and non-prescription pharmaceuticals. To study efficiently some of the potential undesirable effects associated with increasing APAP consumption (e.g., developmental disorders, drug-induced liver injury), there is a need to improve current APAP biomonitoring methods that are limited by APAP short half-life. Here, we demonstrate using high-resolution mass spectrometry (HRMS) in several human studies that APAP thiomethyl metabolite conjugates (S-methyl-3-thioacetaminophen sulfate and S-methyl-3-thioacetaminophen sulphoxide sulfate) are stable biomarkers with delayed excretion rates compared to conventional APAP metabolites, that could provide a more reliable history of APAP ingestion in epidemiological studies. We also show that these biomarkers could serve as relevant clinical markers to diagnose APAP acute intoxication in overdosed patients, when free APAP have nearly disappeared from blood. Using in vitro liver models (HepaRG cells and primary human hepatocytes), we then confirm that these thiomethyl metabolites are directly linked to the toxic N-acetyl-p-benzoquinone imine (NAPQI) elimination, and produced via an overlooked pathway called the thiomethyl shunt pathway. Further studies will be needed to determine whether the production of the reactive hepatotoxic NAPQI metabolites is currently underestimated in human. Nevertheless, these biomarkers could already serve to improve APAP human biomonitoring, and investigate, for instance, inter-individual variability in NAPQI production to study underlying causes involved in APAP-induced hepatotoxicity. Overall, our findings demonstrate the potential of exposomics-based HRMS approach to advance towards a better precision for human biomonitoring.

Emerging Evidence for the Use of Antidiabetic Drugs, Glucagon-like Peptide 1 Receptor Agonists, for the Treatment of Alzheimer's Disease.

From an epidemiological and pathophysiological point of view, Alzheimer's disease (AD) and type 2 diabetes (T2DM) should be considered 'sister' diseases. T2DM significantly increases the risk of developing AD, and the mechanisms of neuronal degeneration themselves worsen peripheral glucose metabolism in multiple ways. The pathophysiological links between the two diseases, particularly cerebral insulin resistance, which causes neuronal degeneration, are so close that AD is sometimes referred to as 'type 3 diabetes'. Although the latest news on the therapeutic front for AD is encouraging, no treatment has been shown to halt disease progression permanently. At best, the treatments slow down the progression; at worst, they are inactive, or cause worrying side effects, preventing their use on a larger scale. Therefore, it appears logical that optimizing the metabolic milieu through preventive or curative measures can also slow down the cerebral degeneration that characterizes AD. Among the different classes of hypoglycaemic drugs, glucagon-like peptide 1 receptor agonists, which are widely used in the treatment of T2DM, were shown to slow down, or even prevent, neuronal degeneration. Data from animal, preclinical, clinical phase II, cohort and large cardiovascular outcomes studies are encouraging. Of course, randomized clinical phase III studies, which are on-going, will be essential to verify this hypothesis. Thus, for once, there is hope for slowing down the neurodegenerative processes associated with diabetes, and that hope is the focus of this review.

A methodological review with meta-epidemiological analysis of preclinical systematic reviews with meta-analyses.

Systematic reviews and meta-analyses have been proposed as an approach to synthesize the literature and counteract the lack of power of small preclinical studies. We aimed to evaluate (1) the methodology of these reviews, (2) the methodological quality of the studies they included and (3) whether study methodological characteristics affect effect size. We searched MEDLINE to retrieve 212 systematic reviews with meta-analyses of preclinical studies published from January, 2018 to March, 2020. Less than 15% explored the grey literature. Selection, data extraction and risk of bias assessment were performed in duplicate in less than two thirds of reviews. Most of them assessed the methodological quality of included studies and reported the meta-analysis model. The risk of bias of included studies was mostly rated unclear. In meta-epidemiological analysis, none of the study methodological characteristics was associated with effect size. The methodological characteristics of systematic reviews with meta-analyses of recently published preclinical studies seem to have improved as compared with previous assessments, but the methodological quality of included studies remains poor, thus limiting the validity of their results. Our meta-epidemiological analysis did not show any evidence of a potential association between methodological characteristics of included studies and effect size.

Incretin-induced changes in the transcriptome of skeletal muscles of fa/fa Zucker rat (ZFR) with obesity, without diabetes.

INTRODUCTION: Glucagon-like peptide-1 receptor agonists (GLP-1ra) are increasingly used in treating type 2 diabetes and obesity. Exendin-4 (Ex-4), a long acting GLP-1ra, was previously reported to decrease oxidative stress in hepatocytes, adipocytes and skeletal muscle cells in obese nondiabetic fa/fa Zucker rats (ZFR), thereby improving insulin resistance. AIM: We aimed first to identify Ex-4-induced changes in the transcriptome of skeletal muscle cells in ZFR. RESULTS: Ontology analysis of differentially expressed genes (DEGs) in ZFR versus lean animals (LR) showed that the extracellular matrix (ECM) is the first most affected cellular compartment, followed by myofibrils and endoplasmic reticulum (ER). Interestingly, among 15 genes regulated in ZFR versus LR, 14 of them were inversely regulated by Ex-4, as further confirmed by RT-qPCR. Picro-Sirius red histological staining showed that decreased ECM fiber area in ZFR is partially restored by Ex-4. Ontology analysis of the myofibril compartment revealed that decreased muscle contractile function in ZFR is partially restored by Ex-4, as confirmed by Phalloidin histological staining that showed a partial restoration by Ex-4 of altered contractile apparatus in ZFR. Ontology analysis of ER DEGs in ZFR versus LR showed that some of them are related to the AMP-activated protein kinase (AMPK) signaling pathway. Phosphorylated AMPK levels were strongly increased in Ex-4-treated ZFR. CONCLUSION: Altogether, our results suggest that GLP-1ra strongly restructure ECM and reinforce contractile capabilities in ZFR, while optimizing the cellular metabolism through AMPK.

Transmissible Cancer Evolution: The Under-Estimated Role of Environmental Factors in the "Perfect Storm" Theory.

Although the true prevalence of transmissible cancers is not known, these atypical malignancies are likely rare in the wild. The reasons behind this rarity are only partially understood, but the "Perfect Storm hypothesis" suggests that transmissible cancers are infrequent because a precise confluence of tumor and host traits is required for their emergence. This explanation is plausible as transmissible cancers, like all emerging pathogens, will need specific biotic and abiotic conditions to be able to not only emerge, but to spread to detectable levels. Because those conditions would be rarely met, transmissible cancers would rarely spread, and thus most of the time disappear, even though they would regularly appear. Thus, further research is needed to identify the most important factors that can facilitate or block the emergence of transmissible cancers and influence their evolution. Such investigations are particularly relevant given that human activities are increasingly encroaching into wild areas, altering ecosystems and their processes, which can influence the conditions needed for the emergence and spread of transmissible cell lines.

Efficacy and safety of steroid-sparing treatments in giant cell arteritis according to the glucocorticoids tapering regimen: A systematic review and meta-analysis.

OBJECTIVES: To assess the efficacy and safety of adjuvant therapies in newly diagnosed or relapsing giant cell arteritis (GCA) in terms of relapse rate at week 52 (primary outcome) and to assess the impact of GC tapering regimen on adjuvant effectiveness. METHODS: For this systematic review and meta-analysis, we searched PubMed, EMBASE, CENTRAL, trial registries, from inception to November 2020. We included all randomized controlled trials (RCTs) and controlled prospective studies evaluating adjuvant treatments in GCA, without date or language restriction. Two reviewers independently selected studies, extracted data and assessed risk of bias. Quality of evidence was summarised with GRADE. RESULTS: Of the 680 records identified, 16 studies were included (1,068 participants) evaluating various adjuvant therapies compared to GC only. No study compared adjuvants with each other. Risk of bias was high in 5/7 trials evaluating our primary outcome. Risk of relapse at week 52 was reduced for only the anti-IL6 and IL6-receptor drug class versus the control (RR=0.45, 95%CI 0.30-0.66, I2=38%), particularly tocilizumab (RR=0.38, 95%CI 0.23-0.63, I2=42%) with a moderate quality of evidence. We found no significant interaction according to GC tapering regimen. Our meta-analysis did not show a significant benefit for methotrexate. Except for dapsone, ciclosporine and hydroxychloroquine, other adjuvants did not seem to show increased risk of adverse events. CONCLUSIONS: Tocilizumab seems to reduce the relapse rate in GCA at week 52 but the quality of evidence was moderate. No other molecule has shown efficacy. No significant interaction on relapse rate by GC tapering regimen was found. STUDY REGISTRATION: PROSPERO CRD42020172011.

Ecological and Evolutionary Consequences of Anticancer Adaptations.

Cellular cheating leading to cancers exists in all branches of multicellular life, favoring the evolution of adaptations to avoid or suppress malignant progression, and/or to alleviate its fitness consequences. Ecologists have until recently largely neglected the importance of cancer cells for animal ecology, presumably because they did not consider either the potential ecological or evolutionary consequences of anticancer adaptations. Here, we review the diverse ways in which the evolution of anticancer adaptations has significantly constrained several aspects of the evolutionary ecology of multicellular organisms at the cell, individual, population, species, and ecosystem levels and suggest some avenues for future research.

Serum IgG2 levels predict long-term protection following pneumococcal vaccination in systemic lupus erythematosus (SLE).

Systemic lupus erythematosus (SLE) patients are at risk for pneumococcal infection. Twenty-one consecutive SLE patients (40[25-75] years) received the sequential PCV13/PPSV23 vaccine and factors associated with long-term protection were analyzed. Immune protection, defined by an antigen-specific IgG concentration ≥1.3 µg/mL for at least 70% of 7 pneumococcal serotypes was assessed at baseline, 2, 6, 12 and 36 months defining long-term protection. Only 10 patients showed pneumococcal immune protection 36 months after vaccination. Eleven (52.4%) patients had no long-term protection with a seroconversion that never or only transiently occurred. SLE disease features, treatment received and immunological characteristics did not differ between protected and unprotected patients except for the pre-vaccination IgG2 serum levels. Serum IgG2 level >2.125 µg/ml showed a sensitivity of 100% and a specificity of 90.9% for long-term protection. Sequential pneumococcal vaccination conferred poor immune protection in SLE. Baseline IgG2 serum level identified patients able to benefit from pneumococcal vaccination.

Modulation of VEGF Expression and Oxidative Stress Response by Iodine Deficiency in Irradiated Cancerous and Non-Cancerous Breast Cells.

Breast cancer remains a major concern and its physiopathology is influenced by iodine deficiency (ID) and radiation exposure. Since radiation and ID can separately induce oxidative stress (OS) and microvascular responses in breast, their combination could additively increase these responses. Therefore, ID was induced in MCF7 and MCF12A breast cell lines by medium change. Cells were then X-irradiated with doses of 0.05, 0.1, or 3 Gy. In MCF12A cells, both ID and radiation (0.1 and 3 Gy) increased OS and vascular endothelial growth factor (VEGF) expression, with an additive effect when the highest dose was combined with ID. However, in MCF7 cells no additive effect was observed. VEGF mRNA up-regulation was reactive oxygen species (ROS)-dependent, involving radiation-induced mitochondrial ROS. Results on total VEGF mRNA hold true for the pro-angiogenic isoform VEGF165 mRNA, but the treatments did not modulate the anti-angiogenic isoform VEGF165b. Radiation-induced antioxidant response was differentially regulated upon ID in both cell lines. Thus, radiation response is modulated according to iodine status and cell type and can lead to additive effects on ROS and VEGF. As these are often involved in cancer initiation and progression, we believe that iodine status should be taken into account in radiation prevention policies.

Transmissible Cancers in an Evolutionary Perspective.

Inter-individual transmission of cancer cells represents an intriguing and unexplored host-pathogen system, with significant ecological and evolutionary ramifications. The pathogen consists of clonal malignant cell lines that spread horizontally as allografts and/or xenografts. Although only nine transmissible cancer lineages in eight host species from both terrestrial and marine environments have been investigated, they exhibit evolutionary dynamics that may provide novel insights into tumor-host interactions particularly in the formation of metastases. Here we present an overview of known transmissible cancers, discuss the necessary and sufficient conditions for cancer transmission, and provide a comprehensive review on the evolutionary dynamics between transmissible cancers and their hosts.

[Heart failure, improve the return home]. / Insuffisance cardiaque, améliorer le retour à domicile.

Heart failure, a serious and progressive disease, mainly affects the elderly. The Vendée coastline attracts high numbers of retired people to the region. Faced with this observation, Vendée departmental hospital deemed it necessary to put in place a monitoring unit providing adapted care in order to reduce the rate of mortality and rehospitalisation. The implementation of the Return Home programme has had a positive impact on the optimised care management of patients.

Acute iodine deficiency induces a transient VEGF-dependent microvascular response in mammary glands involving HIF-1, ROS, and mTOR.

Iodine deficiency (ID), which affects almost two billion people worldwide, is associated with breast pathologies such as fibrosis in human and induces breast atypia in animal models. Because ID induces vascular activation in the thyroid, another iodide-uptaking organ, and as breast is also sensitive to ID, we aimed to characterize ID-induced effects on the breast microvasculature in vivo and in two different breast cell lines in vitro. Virgin and lactating NMRI mice received an iodide-deficient diet and a Na+/I- symporter inhibitor for 1 to 20 days. Some virgin mice were treated with vascular endothelial growth factor A (VEGF) or VEGF receptor inhibitors. In vitro, ID was induced in MCF7 and MCF12A cells by replacing the iodide-containing medium by an iodide-deficient medium. In vivo, VEGF expression was increased following ID in mammary tissues. Consequently, ID induced a transient increase in mammary gland blood flow, measured after anesthesia, in virgin and lactating mice, which was repressed by VEGF or VEGF receptor inhibitors. In MCF7 cells, ID induced a transient increase in reactive oxygen species, followed by an increase in hypoxia-inducible factor-1α (HIF-1α) protein and VEGF mRNA expression. Antioxidant N-acetylcysteine and mammalian target of rapamycin (mTOR) inhibitor blocked ID-induced HIF-1α protein increase and VEGF transcription. However, mTOR activity was not inhibited by N-acetylcysteine. Similar responses were observed in MCF12A cells. These data indicate that ID activates the canonical VEGF pathway and mTOR in breast tissues, which provides new insights to better understand the correlation between ID, vascular activation, and breast pathologies.

[Improving the management of heart failure in the Vendée]. / Améliorer la prise en charge de l'insuffisance cardiaque en Vendée.

Heart failure is a serious condition which affects mainly elderly people. In the Vendée region, where many people choose to retire, hospital teams have noticed an increase in hospitalisations for heart failure. To optimise the management of these patients, a follow-up service was set up in July 2016 comprising a PRADO programme specifically supporting the return home of patients with heart failure.

The new FreeStyle libre flash glucose monitoring system improves the glycaemic control in a cohort of people with type 1 diabetes followed in real-life conditions over a period of one year.

AIMS: Using the novel FreeStyle Libre (FSL), glucose monitoring (FGM) system becomes increasingly popular among people with type 1 diabetes (T1D) and is associated with less and shorter hypoglycaemic events without deterioration of HbA1c. There are not yet data reporting the impact of FGM in people with T1D in real-life conditions. We sought of evaluating the tolerance, the acceptance and the efficacy of the FGM system in routine medical practice. METHODS: This 12-month observational study included 120 individuals with T1D evaluated every 3 months. After having been instructed about FGM utilization, participants were trained to optimize the glycaemic control. RESULTS: Participants stopped immediately of measuring capillary blood glucose (2.88 ± 0.12 per day) (mean ± SEM) after having received the first FSL device and the number of scans per day increased up to 8.87 ± 0.58 per day. HbA1c levels decreased from 8.51% ± 0.14% at baseline to 7.77% ± 0.09% after 3 months to slightly increase to 7.92% ± 0.09% at 12 months, in correlation with the number of scans per day. The number (but not the duration) of hypoglycaemic events slightly increased from 16.9 ± 1.44 per month at baseline to 24.0 ± 2.91 per month at 12 months, after reaching a peak of 26.4 ± 2.31 per month at 6 months. They were correlated with improved HbA1c. CONCLUSION: Our study shows that using the FGM system improves HbA1c levels in people with T1D along with a moderate increase in the number of mild hypoglycaemic events. The new FGM system facilitates the therapeutic empowerment of people with T1D, but in a context of structured education.

Experimental Biodiversity Enrichment in Oil-Palm-Dominated Landscapes in Indonesia.

Tropical biodiversity is threatened by the expansion of oil-palm plantations. Reduced-impact farming systems such as agroforests, have been proposed to increase biodiversity and ecosystem functioning. In regions where oil-palm plantations already dominate the landscape, this increase can only be achieved through systematic ecological restoration. However, our knowledge about the underlying ecological and socio-economic processes, constraints, and trade-offs of ecological restoration in oil-palm landscapes is very limited. To bridge this gap, we established a long-term biodiversity enrichment experiment. We established experimental tree islands in a conventional oil-palm plantation and systematically varied plot size, tree diversity, and tree species composition. Here, we describe the rationale and the design of the experiment, the ecosystem variables (soil, topography, canopy openness) and biotic characteristics (associated vegetation, invertebrates, birds) of the experimental site prior to the establishment of the experiment, and initial experimental effects on the fauna. Already one year after establishment of the experiment, tree plantings had an overall positive effect on the bird and invertebrate communities at the plantation scale. The diversity and abundance of invertebrates was positively affected by the size of the tree islands. Based on these results, we expect a further increase of biodiversity and associated ecological functions in the future. The long-term interdisciplinary monitoring of ecosystem variables, flora, fauna, and socio-economic aspects will allow us to evaluate the suitability of tree islands as a restoration measure. Thereof, guidelines for ecologically improved and socio-economically viable restoration and management concepts could be developed.

Extrapancreatic effects of incretin hormones: evidence for weight-independent changes in morphological aspects and oxidative status in insulin-sensitive organs of the obese nondiabetic Zucker rat (ZFR).

Incretin-based therapies are widely used to treat type 2 diabetes. Although hypoglycemic actions of incretins are mostly due to their insulinotropic/glucagonostatic effects, they may also influence extrapancreatic metabolism. We administered exendin-4 (Ex-4), a long-acting glucagon-like peptide receptor agonist, at low dose (0.1 nmol/kg/day) for a short period (10 days), in obese nondiabetic fa/fa Zucker rats (ZFRs). Ex-4-treated ZFRs were compared to vehicle (saline)-treated ZFRs and vehicle- and Ex-4-treated lean rats (LRs). Blood glucose levels were measured at days 0, 9, and 10. Ingested food and animal weight were recorded daily. On the day of sacrifice (d10), blood was sampled along with liver, epididymal, subcutaneous, brown adipose, and skeletal muscle tissues from animals fasted for 24 h. Plasma insulin and blood glucose levels, food intake, and body and epididymal fat weight were unchanged, but gross morphological changes were observed in insulin-sensitive tissues. The average size of hepatocytes was significantly lower in Ex-4-treated ZFRs, associated with decreased number and size of lipid droplets and 4-hydroxy-2-nonenal (HNE) staining, a marker of oxidative stress (OS). Myocytes, which were smaller in ZFRs than in LRs, were significantly enlarged and depleted of lipid droplets in Ex-4-treated ZFRs. Weak HNE staining was increased by Ex-4. A similar observation was made in brown adipose tissue, whereas the elevated HNE staining observed in epididymal adipocytes of ZFRs, suggestive of strong OS, was decreased by Ex-4. These results suggest that incretins by acting on OS in insulin-sensitive tissues may contribute to weight-independent improvement in insulin sensitivity.

Iodine deficiency induces a VEGF-dependent microvascular response in salivary glands and in the stomach.

Despite efforts to optimize iodine supply in iodine deficient countries, iodine deficiency (ID) remains a global problem worldwide. Activation of the local microvasculature by ID in the thyroid gland aims at improving the local supply of iodide. For this purpose, the thyrocytes secrete vascular endothelial growth factor (VEGF) that acts on adjacent capillaries, via a reactive oxygen species (ROS)/Hypoxia Inducible factor (HIF)-dependent pathway. Beside the thyroid, other organs including salivary glands and the stomach do express the sodium/iodide symporter (NIS) and are able to take iodide up, potentially rendering them sensitive to ID. To verify this hypothesis, ID-induced effects on the local microvasculature were studied in salivary glands and in the stomach. ID was induced by feeding young mice with an iodide-deficient diet and NIS inhibitor perchlorate in the drinking water. In salivary glands, ID induced a transient increase in HIF-1α protein expression accompanied by a transient, VEGF-dependent increase in blood flow. In the gastric mucosa, ID transiently increased VEGF expression in the mucin-secreting epithelium and in ghrelin-secreting endocrine cells. These observations suggest that microvascular changes in response to ID occur in NIS-expressing tissues other than the thyroid. NIS expressing cells could be viewed as iodide sensors that respond to ID by inducing vascular changes, probably to optimize iodide bioavailability at regional or systemic levels.

The expression of dual oxidase, thyroid peroxidase, and caveolin-1 differs according to the type of immune response (TH1/TH2) involved in thyroid autoimmune disorders.

CONTEXT: Hashimoto's thyroiditis (HT) and Graves' disease (GD) are thyroid autoimmune disorders driven by Th1 and Th2 immune responses, respectively. Caveolin-1 (Cav-1), thyroid peroxidase (TPO), and dual oxidase (DUOX) are thought to be part of the thyroxisome, which is essential to maintain thyroid hormone synthesis, at the apical membrane. OBJECTIVES: To analyze the thyroxisome in HT and GD thyroids, we investigated Cav-1, DUOX, and TPO expression as well as markers of oxidative stress (OS), cell proliferation, apoptosis, and antioxidant defenses. The effects of cytokines on Cav-1 expression were analyzed in vitro. RESULTS: In HT, the decrease in Cav-1, DUOX, and TPO expression was marked in follicles having the morphological aspect of active follicles in normal glands and thus called active-like follicles. T4 was not detected in the colloid but in the cytoplasm as well as DUOX and TPO. These abnormalities were associated with increased OS and cell damage. In the hypofunctioning follicles of HT and normal thyroids, Cav-1, DUOX, and TPO were not expressed. In GD, they were expressed at the apical pole of thyrocytes, and T4 accumulated in the colloid of all follicles. Th1 cytokines IL-1α/interferonγ decreased Cav-1 expression in vitro, whereas the Th2 cytokine IL-4 had no effect. CONCLUSION: Th1 cytokine-induced down-regulation of Cav-1 could be responsible for intracytoplasmic T4 synthesis and mislocalization of DUOX and TPO, suggesting an important role for Cav-1 in the preservation of thyroxisome integrity. The thyroxisome's disruption, leading to uncontrolled OS and cell apoptosis, is a key, event in HT pathogenesis.