Phthalate esters modulate the differentiation and maturation of mouse peripheral blood mononuclear cell-derived dendritic cells

Diethylhexyl phthalate induces immune dysregulation and is an environmental immune disruptor

Diethylhexyl phthalate (DEHP) is the most abundant phthalate compound in the environment, and has been linked with multiple human diseases. The immune system is closely associated with the occurrence and progression of various diseases. However, minimal research has addressed the impact of DEHP on the immune system. In this study, single-cell RNA sequencing was performed using spleen tissue of mice to comprehensively determine alterations of the immune system in response to DEHP. The results showed that DEHP exposure reduced the absolute number of peripheral white blood cells (WBCs), including lymphocytes, monocytes, eosinophils, basophils, and neutrophils in mice. In addition, scRNA-seq analyses showed that inflammatory signaling and the expression of heat shock proteins (HSPs) were reduced in all peripheral immune cell populations. Furthermore, we established a mice cecal ligation and puncture (CLP) model, and showed that DEHP exacerbated sepsis-induced immunosuppression and organ damage. These results suggest that DEHP is an environmental immune disruptor that undermines the immune system, exacerbating acute infections and organ damage. Our findings offer a novel perspective on the hazards of DEHP to human health.

Lineage-Selective Disturbance of Early Human Hematopoietic Progenitor Cell Differentiation by the Commonly Used Plasticizer Di-2-ethylhexyl Phthalate via Reactive Oxygen Species: Fatty Acid Oxidation Makes the Difference

Exposure to ubiquitous endocrine-disrupting chemicals (EDCs) is a major public health concern. We analyzed the physiological impact of the EDC, di-2-ethylhexyl phthalate (DEHP), and found that its metabolite, mono-2-ethylhexyl phthalate (MEHP), had significant adverse effects on myeloid hematopoiesis at environmentally relevant concentrations. An analysis of the underlying mechanism revealed that MEHP promotes increases in reactive oxygen species (ROS) by reducing the activity of superoxide dismutase in all lineages, possibly via its actions at the aryl hydrocarbon receptor. This leads to a metabolic shift away from glycolysis toward the pentose phosphate pathway and ultimately results in the death of hematopoietic cells that rely on glycolysis for energy production. By contrast, cells that utilize fatty acid oxidation for energy production are not susceptible to this outcome due to their capacity to uncouple ATP production. These responses were also detected in non-hematopoietic cells exposed to alternate inducers of ROS.

Mechanistic insight into toxicity of phthalates, the involved receptors, and the role of Nrf2, NF-κB, and PI3K/AKT signaling pathways

The wide use of phthalates, as phthalates are used in the manufacturing of not only plastics but also many others goods, has become a main concern in the current century because of their potency to induce deleterious effects on organism health. The toxic effects of phthalates such as reproductive toxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, teratogenicity, and tumor development have been widely indicated by previous experimental studies. Some of the important mechanisms of toxicity by phthalates are the induction and promotion of inflammation, oxidative stress, and apoptosis. Awareness of the involved molecular pathways of these mechanisms will permit the detection of exact molecular targets of phthalates to protect or treat their toxicity. Up to now, various transcription factors and signaling pathways have been associated with phthalate-induced toxicity which by influencing on nuclear surface and the expression of different genes can alter cell hemostasis. In different studies, the role of nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor-κB (NF-κB), and phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathways in processes of oxidative stress, inflammation, apoptosis, and cancer has been shown following exposure to phthalates. In the present review, we aim to survey experimental studies (in vitro and in vivo) in order to show firstly the most involved receptors and also the importance and the role of the mentioned signaling pathways in phthalate-induced toxicity, and with considering this point, the future studies can focus on these molecular targets as a strategic method to reduce environmental chemicals-induced toxicity especially phthalates toxic effects.

Interplay Between Endocrine Disruptors and Immunity: Implications for Diseases of Autoreactive Etiology

The sex-bias of disease susceptibility has remained a puzzling aspect of several autoimmune conditions, including post-infection viral autoimmunity. In the last half of the twentieth century, the incidence rate of female-biased autoimmunity has steadily increased independent of medical advances. This has suggested a role for environmental factors, such as endocrine disrupting chemicals, which have been described to interfere with endocrine signaling. Endocrine involvement in the proper function of innate and adaptive immunity has also been defined, however, these two areas have rarely been reviewed in correlation. In addition, studies addressing the effects of endocrine disruptors have reported findings resulting from a broad range of exposure doses, schedules and models. This experimental heterogeneity adds confusion and may mislead the translation of findings to human health. Our work will normalize results across experiments and provide a necessary summary relevant to human exposure. Through a novel approach, we describe how different categories of ubiquitously used environmental endocrine disruptors interfere with immune relevant endocrine signaling and contribute to autoimmunity. We hope this review will guide identification of mechanisms and concentration-dependent EDC effects important not only for the sex-bias of autoimmunity, but also for other conditions of immune dysfunction, including post-infection autoreactivity such as may arise following severe acute respiratory syndrome coronavirus 2, Epstein-Barr virus, Herpes Simplex virus.

Phthalate exposure and allergic diseases: Review of epidemiological and experimental evidence

Phthalates are among the most ubiquitous environmental contaminants and endocrine-disrupting chemicals. Exposure to phthalates and related health effects have been extensively studied over the past four decades. An association between phthalate exposure and allergic diseases has been suggested, although the literature is far from conclusive. This article reviews and evaluates epidemiological (n = 43), animal (n = 49), and cell culture studies (n = 42), published until the end of 2019, on phthalates and allergic diseases, such as asthma, rhinoconjunctivitis, and eczema. In contrast to earlier reviews, emphasis is placed on experimental studies that use concentrations with relevance for human exposure. Epidemiological studies provide support for associations between phthalate exposures and airway, nasal, ocular, and dermal allergic disease outcomes, although the reported significant associations tend to be weak and demonstrate inconsistencies for any given phthalate. Rodent studies support that phthalates may act as adjuvants at levels likely to be relevant for environmental exposures, inducing respiratory and inflammatory effects in the presence of an allergen. Cell culture studies demonstrate that phthalates may alter the functionality of innate and adaptive immune cells. However, due to limitations of the applied exposure methods and models in experimental studies, including the diversity of phthalates, exposure routes, and allergic diseases considered, the support provided to the epidemiological findings is fragmented. Nevertheless, the current evidence points in the direction of concern. Further research is warranted to identify the most critical windows of exposure, the importance of exposure pathways, interactions with social factors, and the effects of co-exposure to phthalates and other environmental contaminants.

Phthalate Exposure and Long-Term Epigenomic Consequences: A Review

Phthalates are esters of phthalic acid which are used in cosmetics and other daily personal care products. They are also used in polyvinyl chloride (PVC) plastics to increase durability and plasticity. Phthalates are not present in plastics by covalent bonds and thus can easily leach into the environment and enter the human body by dermal absorption, ingestion, or inhalation. Several in vitro and in vivo studies suggest that phthalates can act as endocrine disruptors and cause moderate reproductive and developmental toxicities. Furthermore, phthalates can pass through the placental barrier and affect the developing fetus. Thus, phthalates have ubiquitous presence in food and environment with potential adverse health effects in humans. This review focusses on studies conducted in the field of toxicogenomics of phthalates and discusses possible transgenerational and multigenerational effects caused by phthalate exposure during any point of the life-cycle.

OX40L induces helper T cell differentiation during cell immunity of asthma through PI3K/AKT and P38 MAPK signaling pathway

Background

The aim of this study was to investigate the mechanisms of OX40L in regulating helper T (Th) cells differentiation through phosphoinositide 3-kinase (PI3K)/AKT and p38 mitogen-activated protein kinase signaling pathway in vitro and in vivo experiments.

Methods

Serum samples of patients with asthma and healthy controls were used to explore the association between OX40L and Th cells. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum concentrations of OX40L, IL-4, IFN-γ, IL-17 and TGF-β. Flow cytometry method was used to analyze Th1, Th2, Th17 and Treg cells. 3H-thymidine was used to determine the proliferation of T cells. Western Blot was used to detect protein expression and phosphorylation. Immunohistochemistry was used to detect the expression of OX40L in lung tissues.

Results

OX40L, IL-4, IL-17 increased in patient serum compared to healthy control and in the ovalbumin (OVA)-primed mononuclear cells compared to normal cells, while IFN-γ and TGF-β were decreased. Besides, the OVA-primed CD4⁺ T cells treated with OX40L-Ig fusion protein promoted the proliferation of T cells and Th2 and Th17 cells differentiation as well as PI3K/AKT and p38 MAPK signaling pathway, but suppressed Th1 and Treg cells differentiation. Moreover, helper T cells differentiation in OVA-primed CD4⁺ T cells could be markedly reversed by the addition of PI3K/AKT inhibition, p38 MAPK inhibition and anti-OX40L monoclonal antibody.

Conclusions

In this study, we revealed that OX40L could regulate differentiation of helper T cells via PI3K/AKT and p38 MAPK signaling pathway in asthma. Besides, blockade of OX40/OX40L could inhibit the proliferation of CD4⁺ T cells and regulate polarization of helper T cells.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1436-4) contains supplementary material, which is available to authorized users.

Influence of Di(2-ethylhexyl)phthalate on migration rate and differentiation of human hematopoietic stem and progenitor cells (CD34+)

INTRODUCTION

Phthalates are a group of synthetic plasticizers that are ubiquitous environmental pollutants with toxic and endocrine disrupting characteristics. DEHP is the most commonly used plasticizer in the world and is still applied to stem cell transfusion bags used for storage of hematopoietic stem and progenitor cells (CD34+ HSPC), which are transferred during stem cell transplantation. Here we examined the effect of DEHP on vitality of CD34+ HSPC as well as stem cell specific properties like migration and differentiation capacity - both important for successful stem cell transplantations.

MATERIAL AND METHODS

CD34+ HSPC were incubated for 24 h and 72 h with DEHP concentrations ranging from 1 μg/ml to 250 μg/ml. DEHP was diluted in DMSO. Migration rate was analyzed along an SDF-1α gradient using Transwell migration inserts. Differentiation of CD34+ HSPC was investigated after two weeks in methylcellulose with colony stimulating factors. Apoptosis rate was measured via Annexin V and 7-AAD staining.

RESULTS

24 h of incubation with 10 μg/ml DEHP led to a significant (p <  0.01) decrease in migration rate of CD34+ HSPC (70.70% ± 7.53% ) with a minimum migration rate of 48.33% ± 6.72% in relation to control after incubation with 100 μg/ml DEHP for 72 h. Incubation with the highest tested DEHP concentrations (50 and 100 μg/ml) significantly (p <  0.05) altered colony formation rate and cell type distribution. Apoptosis rate of CD34+ HSPC significantly (p <  0.05) increased after incubation with concentrations of 10 μg/ml DEHP for 24 h (1.46 ± 0.19) with a maximum apoptosis rate of 2.71 ± 0.66 after 24 h incubation with the highest DEHP concentration (250 μg/ml) in relation to control.

CONCLUSIONS

As shown, DEHP takes impact on migration rate, apoptosis rate, and differentiation of CD34+ HSPC. As these are functions with an important role in stem cell transplantations, the usage of DEHP-free stem cell transfusion bags should be considered.

Effects of some endocrine disruptors on cell cycle progression and murine dendritic cell differentiation

Endocrine disruptor chemicals (EDCs), which are predominantly present in the environment, are able to mimic or antagonise the biological activity of hormones primarily through the interaction with specific receptors. The main consequences are adverse effects on the growth and development of reproductive organs, the induction of cancer and effects on neuronal differentiation. In this study, we investigated the ability of certain EDCs, Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol F (BPF), 4-n Nonylphenol (NP) and Octylphenol (OP), belonging to a homogeneous group of phenol origin, to interfere with specific cellular processes, namely, proliferation, by using MCF-7 breast carcinoma cells, and differentiation, by using murine bone marrow dendritic cells. We correlated the data on cell growth with the stimulation of cell cycle progression, which could become a step in the development of cancer, and we established a proliferation ranking between the tested EDCs: NP>BPA>OP>BPB>BPF. In addition, we investigated the ability of NP, BPA and OP to induce the differentiation of dendritic cells, the powerful antigen-presenting cells of the immune system. The differentiation and activation of these cells could affect a well-regulated immune response and determine an allergic sensitisation. We found that BPA and NP were active in determining differentiation.