A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here, we examined how CD8+ tumor infiltrating lymphocytes (TILs) ...respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8+ TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8+ TILs, which also correlated with progressive T cell dysfunction. Cd36−/− T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells, and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by overexpression of glutathione peroxidase 4 restored functionalities in CD8+ TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8+ T cell dysfunction and serves as a therapeutic avenue for immunotherapies.
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•The tumor microenvironment is enriched with lipids and oxidized lipids•Dysfunctional CD8+ TILs increase CD36 expression and OxLDL uptake•OxLDL uptake via CD36 inhibits T cell effector functions through lipid peroxidation•GPX4 overexpression promotes CD8+ TIL functionality
Lipid accumulation is a common metabolic alteration in the tumor microenvironment. Xu et al. show that intratumoral CD8+ T cells adapt to increased lipid concentrations by increasing expression of the scavenger receptor CD36. This, in turn, leads to intracellular accumulation of oxidized lipid and T cell dysfunction downstream of lipid peroxidation.
With few exceptions, the marked advances in knowledge about the genetic basis of schizophrenia have not converged on findings that can be confidently used for precise experimental modeling. By ...applying knowledge of the cellular taxonomy of the brain from single-cell RNA sequencing, we evaluated whether the genomic loci implicated in schizophrenia map onto specific brain cell types. We found that the common-variant genomic results consistently mapped to pyramidal cells, medium spiny neurons (MSNs) and certain interneurons, but far less consistently to embryonic, progenitor or glial cells. These enrichments were due to sets of genes that were specifically expressed in each of these cell types. We also found that many of the diverse gene sets previously associated with schizophrenia (genes involved in synaptic function, those encoding mRNAs that interact with FMRP, antipsychotic targets, etc.) generally implicated the same brain cell types. Our results suggest a parsimonious explanation: the common-variant genetic results for schizophrenia point at a limited set of neurons, and the gene sets point to the same cells. The genetic risk associated with MSNs did not overlap with that of glutamatergic pyramidal cells and interneurons, suggesting that different cell types have biologically distinct roles in schizophrenia.
Chronic intermittent hypoxia (CIH) is the dominant pathological feature of human obstructive sleep apnoea (OSA), which is highly prevalent and associated with cardiovascular and renal diseases. CIH ...causes hypertension, centred on sympathetic nervous overactivity, which persists following removal of the CIH stimulus. Molecular mechanisms contributing to CIH‐induced hypertension have been carefully delineated. However, there is a dearth of knowledge on the efficacy of interventions to ameliorate high blood pressure in established disease. CIH causes endothelial dysfunction, aberrant structural remodelling of vessels and accelerates atherosclerotic processes. Pro‐inflammatory and pro‐oxidant pathways converge on disrupted nitric oxide signalling driving vascular dysfunction. In addition, CIH has adverse effects on the myocardium, manifesting atrial fibrillation, and cardiac remodelling progressing to contractile dysfunction. Sympatho‐vagal imbalance, oxidative stress, inflammation, dysregulated HIF‐1α transcriptional responses and resultant pro‐apoptotic ER stress, calcium dysregulation, and mitochondrial dysfunction conspire to drive myocardial injury and failure. CIH elaborates direct and indirect effects in the kidney that initially contribute to the development of hypertension and later to chronic kidney disease. CIH‐induced morphological damage of the kidney is dependent on TLR4/NF‐κB/NLRP3/caspase‐1 inflammasome activation and associated pyroptosis. Emerging potential therapies related to the gut–kidney axis and blockade of aryl hydrocarbon receptors (AhR) are promising. Cardiorenal outcomes in response to intermittent hypoxia present along a continuum from adaptation to maladaptation and are dependent on the intensity and duration of exposure to intermittent hypoxia. This heterogeneity of OSA is relevant to therapeutic treatment options and we argue the need for better stratification of OSA phenotypes.
figure legend Chronic intermittent hypoxia (CIH) refers to a pathological pattern of oxygen dysregulation, characterised by brief (seconds‐to‐minutes), recurrent cycling between normal physiological and low levels of O2 (multiple events per hour), that is prolonged (days‐to‐years). CIH induces molecular and functional responses in the heart, vessels and kidneys that initially might be protective and adaptive but become deleterious according to the severity and chronicity of the exposure. In rodents, there is some consensus that exposure to 10% O2, 15 cycles/h, 12 h/day, less than 14 days is a mild/short‐term CIH paradigm while exposure to 2–5% O2, 48 cycles/h, 6 h/day, for 30 days is severe/long‐term and causes detrimental effects. The molecular pattern caused by CIH has many similarities among the heart, vessels and kidney and is compatible with sympathetic and renin–angiotensin–aldosterone system activation, HIF activation, oxidative stress and inflammation. The translation of the molecular signatures found in rodent models to humans is a challenge to be addressed in the future to allow a better patient stratification and to predict responses to drug and mainstay treatments such as continuous positive airway pressure (CPAP). CHOP, C/EBP homologous protein (endoplasmic reticulum stress‐induced apoptosis pathway); EPO, erythropoietin; ET‐1, endothelin‐1; HIF, hypoxia inducible factor; iNOS, inducible nitric oxide synthase; VEGF, vascular endothelial growth factor.
Recent evidence supports the use of an early, short course of glucocorticoids in patients with COVID-19 who require mechanical ventilation or oxygen support. As the number of coronavirus disease 2019 ...(COVID-19) cases continues to increase, the number of pregnant women with the disease is very likely to increase as well. Because pregnant women are at increased risk for hospitalization, intensive care unit admission, and mechanical ventilation support, obstetricians will be facing the dilemma of initiating maternal corticosteroid therapy while weighing its potential adverse effects on the fetus (or neonate if the patient is postpartum and breastfeeding). Our objective is to summarize the current evidence supporting steroid therapy in the management of patients with acute respiratory distress syndrome and COVID-19 and to elaborate on key modifications for the pregnant patient.
Herbivory is fundamental to the regulation of both global food webs and the extent of agricultural crop losses. Induced plant responses to herbivores promote resistance and often involve the ...perception of specific herbivore-associated molecular patterns (HAMPs); however, precisely defined receptors and elicitors associated with herbivore recognition remain elusive. Here, we show that a receptor confers signaling and defense outputs in response to a defined HAMP common in caterpillar oral secretions (OS). Staple food crops, including cowpea (Vigna unguiculata) and common bean (Phaseolus vulgaris), specifically respond to OS via recognition of proteolytic fragments of chloroplastic ATP synthase, termed inceptins. Using forward-genetic mapping of inceptin-induced plant responses, we identified a corresponding leucine-rich repeat receptor, termed INR, specific to select legume species and sufficient to confer inceptin-induced responses and enhanced defense against armyworms (Spodoptera exigua) in tobacco. Our results support the role of plant immune receptors in the perception of chewing herbivores and defense.
Background Consumption of fructose-rich diets in the United States is on the rise and thought to be associated with obesity and cardiometabolic diseases. Objective We sought to determine the effects ...of antenatal exposure to high-fructose diet on offspring’s development of metabolic syndrome–like phenotype and other cardiovascular disease risk factors later in life. Study Design Pregnant C57BL/6J dams were randomly allocated to fructose solution (10% wt/vol, n = 10) or water (n = 10) as the only drinking fluid from day 1 of pregnancy until delivery. After weaning, pups were started on regular chow, and evaluated at 1 year of life. We measured percent visceral adipose tissue and liver fat infiltrates using computed tomography, and blood pressure using CODA nonivasive monitor. Intraperitoneal glucose tolerance testing with corresponding insulin concentrations were obtained. Serum concentrations of glucose, insulin, triglycerides, total cholesterol, leptin, and adiponectin were measured in duplicate using standardized assays. Fasting homeostatic model assessment was also calculated to assess insulin resistance. P values <.05 were considered statistically significant. Results Maternal weight, pup number, and average weight at birth were similar between the 2 groups. Male and female fructose group offspring had higher peak glucose and area under the intraperitoneal glucose tolerance testing curve compared with control, and higher mean arterial pressure compared to control. Female fructose group offspring were heavier and had higher percent visceral adipose tissue, liver fat infiltrates, homeostatic model assessment of insulin resistance scores, insulin area under the intraperitoneal glucose tolerance testing curve, and serum concentrations of leptin, and lower concentrations of adiponectin compared to female control offspring. No significant differences in these parameters were noted in male offspring. Serum concentrations of triglycerides or total cholesterol were not different between the 2 groups for either gender. Conclusion Maternal intake of high fructose leads to fetal programming of adult obesity, hypertension, and metabolic dysfunction, all risk factors for cardiovascular disease. This fetal programming is more pronounced in female offspring. Limiting intake of high fructose–enriched diets in pregnancy may have significant impact on long-term health.
Osteoporosis is a disease characterized by impairment of bone microarchitecture that causes high socioeconomic impacts in the world because of fractures and hospitalizations. Although dual-energy ...X-ray absorptiometry (DXA) is the gold standard for diagnosing the disease, access to DXA in developing countries is still limited due to its high cost, being present only in specialized hospitals. In this paper, we analyze the performance of Osseus, a low-cost portable device based on electromagnetic waves that measures the attenuation of the signal that crosses the medial phalanx of a patient's middle finger and was developed for osteoporosis screening. The analysis is carried out by predicting changes in bone mineral density using Osseus measurements and additional common risk factors used as input features to a set of supervised classification models, while the results from DXA are taken as target (real) values during the training of the machine learning algorithms. The dataset consisted of 505 patients who underwent osteoporosis screening with both devices (DXA and Osseus), of whom 21.8% were healthy and 78.2% had low bone mineral density or osteoporosis. A cross-validation with k-fold = 5 was considered in model training, while 20% of the whole dataset was used for testing. The obtained performance of the best model (Random Forest) presented a sensitivity of 0.853, a specificity of 0.879, and an F1 of 0.859. Since the Random Forest (RF) algorithm allows some interpretability of its results (through the impurity check), we were able to identify the most important variables in the classification of osteoporosis. The results showed that the most important variables were age, body mass index, and the signal attenuation provided by Osseus. The RF model, when used together with Osseus measurements, is effective in screening patients and facilitates the early diagnosis of osteoporosis. The main advantages of such early screening are the reduction of costs associated with exams, surgeries, treatments, and hospitalizations, as well as improved quality of life for patients.
The Scientific Committee (SC) reconfirms that the benchmark dose (BMD) approach is a scientifically more advanced method compared to the no‐observed‐adverse‐effect‐level (NOAEL) approach for deriving ...a Reference Point (RP). The major change compared to the previous Guidance (EFSA SC, 2017) concerns the Section 2.5, in which a change from the frequentist to the Bayesian paradigm is recommended. In the former, uncertainty about the unknown parameters is measured by confidence and significance levels, interpreted and calibrated under hypothetical repetition, while probability distributions are attached to the unknown parameters in the Bayesian approach, and the notion of probability is extended to reflect uncertainty of knowledge. In addition, the Bayesian approach can mimic a learning process and reflects the accumulation of knowledge over time. Model averaging is again recommended as the preferred method for estimating the BMD and calculating its credible interval. The set of default models to be used for BMD analysis has been reviewed and amended so that there is now a single set of models for quantal and continuous data. The flow chart guiding the reader step‐by‐step when performing a BMD analysis has also been updated, and a chapter comparing the frequentist to the Bayesian paradigm inserted. Also, when using Bayesian BMD modelling, the lower bound (BMDL) is to be considered as potential RP, and the upper bound (BMDU) is needed for establishing the BMDU/BMDL ratio reflecting the uncertainty in the BMD estimate. This updated guidance does not call for a general re‐evaluation of previous assessments where the NOAEL approach or the BMD approach as described in the 2009 or 2017 Guidance was used, in particular when the exposure is clearly lower (e.g. more than one order of magnitude) than the health‐based guidance value. Finally, the SC firmly reiterates to reconsider test guidelines given the wide application of the BMD approach.
This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2022.EN-7585/full
Levels of dialkylphosphate (DAP) metabolites were measured in hair and urine of children that lived close to intensively farmed areas of Almeria (Southeast Spain). The levels were used as proxies for ...exposure of these children to organophosphate pesticides (OPs). Determinants of exposure to DAPs were also examined. Urine and hair samples were collected from 222 children aged 3–11 years and information on lifestyle and dietary habits was collected from questionnaires administered to mothers. Urinary DAPs were analyzed by ultra-high performance liquid-chromatography coupled to triple-quadrupole tandem mass-spectrometry (UHPLC-QqQ-MS/MS) and hair DAPs by gas-chromatography coupled to mass spectrometry (GC–MS). Detection rates ranged from 21.8% for diethylphosphate (DEP) and diethylthiophosphate (DETP) to 35.9% for dimethylphosphate (DMP) in urine; and from 42.3% for DETP to 92.8% for DMP in hair. Diethyldithiophosphate (DEDTP) was detected in 0.5% of urine samples (one child), and in 26.6% of children's hair samples. A lack of correlation was observed for individual DAP metabolites and ΣDAPs between urine and hair samples, except for DEDTP. Urinary DAP levels of our child population were lower than those reported for children from other countries, including NHANES 1999–2000 data. The main determinants of hair DAP levels were age, sex, vegetable intake, parental exposure to pesticides at work, time spent playing indoors, monthly income and father's education level. Conversely, none of the predictors studied was significantly associated with urinary DAPs except age. Overall, hair has advantages over urine as it is easier to collect, handle and store, and allows for assessment of cumulative exposure to OPs, thus providing a greater insight for human biomonitoring.
•Dialkylphosphate (DAP) metabolites were measured in hair and urine from children.•No correlation was observed between DAP metabolites in urine and hair samples.•Determinants of DAPs levels were found only for hair samples, not for urine.•Hair may be a better matrix than urine to assess cumulative exposure to OPs.•Hair provides greater insight than urine for human biomonitoring purposes.
The polygenic architecture of schizophrenia implicates several molecular pathways involved in synaptic function. However, it is unclear how polygenic risk funnels through these pathways to translate ...into syndromic illness. Using tensor decomposition, we analyze gene co-expression in the caudate nucleus, hippocampus, and dorsolateral prefrontal cortex of post-mortem brain samples from 358 individuals. We identify a set of genes predominantly expressed in the caudate nucleus and associated with both clinical state and genetic risk for schizophrenia that shows dopaminergic selectivity. A higher polygenic risk score for schizophrenia parsed by this set of genes predicts greater dopamine synthesis in the striatum and greater striatal activation during reward anticipation. These results translate dopamine-linked genetic risk variation into in vivo neurochemical and hemodynamic phenotypes in the striatum that have long been implicated in the pathophysiology of schizophrenia.
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