Phenotypic and Functional Outcomes in Macrophages Exposed to an Environmentally Relevant Mixture of Organophosphate Esters in Vitro.

BACKGROUND: Organophosphate esters (OPEs) are flame retardants and plasticizers used in consumer products. OPEs are found ubiquitously throughout the environment with high concentrations in indoor house dust. Exposure to individual OPEs is associated with immune dysfunction, particularly in macrophages. However, OPEs exist as complex mixtures and the effects of environmentally relevant mixtures on the immune system have not been investigated. OBJECTIVES: The objectives of this study were to evaluate the toxicity of an environmentally relevant mixture of OPEs that models Canadian house dust on macrophages using phenotypic and functional assessments in vitro. METHODS: High-content live-cell fluorescent imaging for phenotypic biomarkers of toxicity in THP-1 macrophages treated with the OPE mixture was undertaken. We used confocal microscopy and cholesterol analysis to validate and expand on the observed OPE-induced lipid phenotype. Then, we used flow cytometry and live-cell imaging to conduct functional tests and uncover mechanisms of OPE-induced phagocytic suppression. Finally, we validated our THP-1 findings in human primary peripheral blood mononuclear cells (hPBMC) derived macrophages. RESULTS: Exposure to non-cytotoxic dilutions of the OPE mixture resulted in higher oxidative stress and disrupted lysosome and lipid homeostasis in THP-1 and primary macrophages. We further observed that phagocytosis of apoptotic cells in THP-1 and primary macrophages was lower in OPE-exposed cells vs. controls. In THP-1 macrophages, phagocytosis of both Gram-positive and Gram-negative bacteria was also lower in OPE-exposed cells vs. controls. Additionally, the OPE mixture altered the expression of phagocytic receptors linked to the recognition of phosphatidylserine and pathogen-associated molecular patterns. DISCUSSION: The results of this in vitro study suggested that exposure to an environmentally relevant mixture of OPEs resulted in higher lipid retention in macrophages and poor efferocytic response. These effects could translate to enhanced foam cell generation resulting in higher cardiovascular mortality. Furthermore, bacterial phagocytosis was lower in OPE-exposed macrophages in an in vitro setting, which may indicate the potential for reduced bacterial clearance in models of infections. Taken together, our data provide strong evidence that mixtures of OPEs can influence the biology of macrophages and offer new mechanistic insights into the impact of OPE mixtures on the immune system. https://doi.org/10.1289/EHP13869.

Dietary Minerals and Incident Cardiovascular Outcomes among Never-Smokers in a Danish Case-Cohort Study.

Background: Diet is known to impact cardiovascular disease (CVD) risk, but evidence for the essential minerals of magnesium (Mg), calcium (Ca), and potassium (K) is inconsistent. Methods: We conducted a case-cohort study within a non-smoking subgroup of the Danish Diet, Cancer and Health cohort, a prospective study of 50-64-year-olds recruited between 1993-1997. We identified incident heart failure (HF), acute myocardial infarction (AMI) and stroke cases through 2015 with an 1135-member subcohort. We measured the dietary intake of minerals, also known as elements, and calculated a combined dietary intake (CDI) score based on joint Ca, Mg and K intakes (mg/d) from Food Frequency Questionnaires. We estimated adjusted hazard ratios (HRs) with Cox proportional hazard models. Results: Most HRs examining associations between CDI score and CVD were null. However, the third quartile of CDI was associated with a lower risk for heart failure (HR: 0.89; 95% CI: 0.67, 1.17), AMI (HR: 0.79; 95% CI: 0.60, 1.04), and stroke (HR: 0.63; 95% CI: 0.44, 0.88). Conclusions: We did not find consistent evidence to suggest that higher levels of essential minerals are associated with incident HF, AMI, and stroke, though results suggest a potential U-shaped relationship between select minerals and CVD outcomes.

scCross: a deep generative model for unifying single-cell multi-omics with seamless integration, cross-modal generation, and in silico exploration.

Single-cell multi-omics data reveal complex cellular states, providing significant insights into cellular dynamics and disease. Yet, integration of multi-omics data presents challenges. Some modalities have not reached the robustness or clarity of established transcriptomics. Coupled with data scarcity for less established modalities and integration intricacies, these challenges limit our ability to maximize single-cell omics benefits. We introduce scCross, a tool leveraging variational autoencoders, generative adversarial networks, and the mutual nearest neighbors (MNN) technique for modality alignment. By enabling single-cell cross-modal data generation, multi-omics data simulation, and in silico cellular perturbations, scCross enhances the utility of single-cell multi-omics studies.

The 11th Conference on metal toxicity and carcinogenesis.

Metal exposure is linked to numerous pathological outcomes including cancer, cardiovascular disease, and diabetes. Over the past decades, we have made significant progress in our understanding of how metals are linked to disease, but there is still much to learn. In October 2022, experts studying the consequences of metal exposures met in Montréal, Québec, to discuss recent advances and knowledge gaps for future research. Here, we present a summary of presentations and discussions had at the meeting.

Tunable PhenoCycler imaging of the murine pre-clinical tumour microenvironments.

BACKGROUND: The tumour microenvironment (TME) consists of tumour-supportive immune cells, endothelial cells, and fibroblasts. PhenoCycler, a high-plex single cell spatial biology imaging platform, is used to characterize the complexity of the TME. Researchers worldwide harvest and bank tissues from mouse models which are employed to model a plethora of human disease. With the explosion of interest in spatial biology, these panoplies of archival tissues provide a valuable resource to answer new questions. Here, we describe our protocols for developing tunable PhenoCycler multiplexed imaging panels and describe our open-source data analysis pipeline. Using these protocols, we used PhenoCycler to spatially resolve the TME of 8 routinely employed pre-clinical models of lymphoma, breast cancer, and melanoma preserved as FFPE. RESULTS: Our data reveal distinct TMEs in the different cancer models that were imaged and show that cell-cell contacts differ depending on the tumour type examined. For instance, we found that the immune infiltration in a murine model of melanoma is altered in cellular organization in melanomas that become resistant to αPD-1 therapy, with depletions in a number of cell-cell interactions. CONCLUSIONS: This work presents a valuable resource study seamlessly adaptable to any field of research involving murine models. The methodology described allows researchers to address newly formed hypotheses using archival materials, bypassing the new to perform new mouse studies.

STAT6 mutations enriched at diffuse large B-cell lymphoma relapse reshape the tumor microenvironment.

Diffuse large B-cell lymphoma (DLBCL) relapses in approximately 40% of patients following frontline therapy. We reported that STAT6D419 mutations are enriched in relapsed/refractory DLBCL (rrDLBCL) samples, suggesting that JAK/STAT signaling plays a role in therapeutic resistance. We hypothesized that STAT6D419 mutations can improve DLBCL cell survival by reprogramming the microenvironment to sustain STAT6 activation. Thus, we investigated the role of STAT6D419 mutations on DLBCL cell growth and its microenvironment. We found that phospho-STAT6D419N was retained in the nucleus longer than phospho-STAT6WT following IL-4 stimulation, and STAT6D419N recognized a more restricted DNA-consensus sequence than STAT6WT. Upon IL-4 induction, STAT6D419N expression led to a higher magnitude of gene expression changes, but in a more selective list of gene targets compared with STATWT. The most significantly expressed genes induced by STAT6D419N were those implicated in survival, proliferation, migration, and chemotaxis, in particular CCL17. This chemokine, also known as TARC, attracts helper T-cells to the tumor microenvironment, especially in Hodgkin's lymphoma. To this end, in DLBCL, phospho-STAT6+ rrDLBCL cells had a greater proportion of infiltrating CD4+ T-cells than phospho-STAT6- tumors. Our findings suggest that STAT6D419 mutations in DLBCL lead to cell autonomous changes, enhanced signaling, and altered composition of the tumor microenvironment.

E-cigarette exposure causes early pro-atherogenic changes in an inducible murine model of atherosclerosis.

Introduction: Evidence suggests that e-cigarette use (vaping) increases cardiovascular disease risk, but decades are needed before people who vape would develop pathology. Thus, murine models of atherosclerosis can be utilized as tools to understand disease susceptibility, risk and pathogenesis. Moreover, there is a poor understanding of how risk factors for atherosclerosis (i.e., hyperlipidemia, high-fat diet) intersect with vaping to promote disease risk. Herein, we evaluated whether there was early evidence of atherosclerosis in an inducible hyperlipidemic mouse exposed to aerosol from commercial pod-style devices and e-liquid. Methods: Mice were injected with adeno-associated virus containing the human protein convertase subtilisin/kexin type 9 (PCSK9) variant to promote hyperlipidemia. These mice were fed a high-fat diet and exposed to room air or aerosol derived from JUUL pods containing polyethylene glycol/vegetable glycerin (PG/VG) or 5% nicotine with mango flavoring for 4 weeks; this timepoint was utilized to assess markers of atherosclerosis that may occur prior to the development of atherosclerotic plaques. Results: These data show that various parameters including weight, circulating lipoprotein/glucose levels, and splenic immune cells were significantly affected by exposure to PG/VG and/or nicotine-containing aerosols. Discussion: Not only can this mouse model be utilized for chronic vaping studies to assess the vascular pathology but these data support that vaping is not risk-free and may increase CVD outcomes later in life.