Recent advances in immunotoxicity and its impact on human health: causative agents, effects and existing treatments

Endocrine disrupters affect the immune system of fish: The example of the European seabass

An organism's fitness critically relies on its immune system to provide protection against parasites and pathogens. The immune system has reached its highest complexity in vertebrates, combining the highly specific adaptive with the non-specific innate immunity. In vertebrates, a complex system of steroid hormones regulates major physiological functions comprising energy metabolism, growth, reproduction and immune system performance. This allows the organism to allocate available energy according to life-history traits and environmental conditions, thus maintaining homeostasis and survival of the individual and of the population. Immune system activation must take into account the developmental stage and the nutritional state of the organism. It should respond adequately to different pathogens, but should not overperform or consume all resources for other physiological functions. This important trade-off between immunity and reproduction is balanced by oestrogen. Many of the thousands of chemicals released by humans into the environment, so-called xenobiotics, have the ability to disrupt normal endocrine function. Such endocrine-disrupting chemicals have been demonstrated to impair reproductive functions and to be responsible for numerous diseases in humans and wild life. Given that oestrogens are established modulators of immune cell populations, exogenous oestrogens and oestrogen mimics can modulate immune functions in aquatic animals, such as fish, potentially affecting wildlife and aquaculture. This review highlights the interaction of xenoestrogens with fish immunity. It particularly focusses on the thymus, a major primary immune organ, in the European seabass, Dicentrarchus labrax an important species, both for fisheries and aquaculture.

Integrated PBPK Modelling for PFOA Exposure and Risk Assessment

Per- and polyfluoroalkyl substances (PFASs) pose significant public health concerns due to their environmental persistence, bioaccumulation, and ubiquitous presence in human biomonitoring (HBM) data, despite regulatory restrictions. This study establishes a deterministic pharmacokinetic model for perfluorooctanoic acid (PFOA), enabling the estimation of PFOA concentrations in major human organs, even at low doses. The model integrates accumulation and recirculation mechanisms of PFOA in hepatic and renal tissues, leveraging publicly available HBM datasets (e.g., HBM4EU, NHANES, literature) to reconstruct bodyweight-normalized intake levels. Importantly, due to the extremely low urinary excretion concentrations of PFOA, most datasets were derived from blood-based measurements, particularly serum while confirming urine as unreliable biomarker of exposure. The analysis underscores the effectiveness of regulatory efforts in reducing PFOA exposures, as evidenced by declining time-trends in estimated exposure levels in recent studies. Risk characterization ratios were calculated based on recommended limits set by the European Food Safety Authority (EFSA), the United States, and Australia. While EFSA's tolerable weekly intake (TWI) indicated a high risk, other regulatory limits suggested less concern about risk at these intake levels. These findings highlight the need for continuous re-evaluation of exposures and targeted studies to identify key determinants of PFOA exposure, informing future regulatory measures. The study emphasizes the critical role of physiologically based pharmacokinetic (PBPK) modeling, HBM data, and exposure reconstruction in advancing chemical risk assessment. These tools form a science-based framework integral to the Chemical Strategy for Sustainability (CSS), enabling accurate predictions of internal exposure levels, empirical validation of models, and robust assessments of real-world exposure scenarios. The integration of these approaches supports the CSS goals of minimizing chemical risks while promoting innovation, ultimately contributing to a sustainable and protective regulatory landscape for human health and the environment.

Multigenerational immunotoxicity assessment: A three-generation study in Drosophila melanogaster upon developmental exposure to triclosan

Triclosan (TCS) is widely used as an antibacterial agent, nevertheless, its presence in different environmental matrices and its persistent environmental nature pose a significant threat to the organism, including humans. Numerous studies showed that TCS exposure could lead to multiple toxicities, including immune dysfunction. However, whether parental TCS exposure could impair the offspring's immune response remains limited. Maintaining the immune homeostasis is imperative to neutralize the pathogen and crucial for tissue repair and the organism's survival. Thus, this study aimed to assess the multigenerational immune response of TCS using Drosophila melanogaster. TCS was administered to organisms (1.0, 10, and 100.0 μg/mL) over three generations during their developing phases, and its effect on the immunological response of the unexposed progeny was evaluated. Total circulatory hemocyte (immune cells) count, crystal cell count, phagocytic activity, clotting time, gene expression related to immune response and epigenetics, ROS generation, and cell death were assessed in the offspring. A concentration-dependent decline in total hemocytes, crystal cells, phagocytic activity, and increased clotting time in the subsequent generations was observed. Furthermore, parental TCS exposure enhanced the ROS levels, induced cell death, and altered the expression of antimicrobial peptides drosomycin, diptericin, and inflammatory genes upd1, upd2, and upd3, in the offspring's hemocytes across successive generations. The upregulation of reaper hid, and grim suggests that TCS promotes apoptotic death in the offspring's hemocytes. Notably, the increased mRNA expression of epigenetic regulators dnmt2 and g9a in the hemocytes of the offspring indicates epigenetic modifications. Further, we also observed that the antioxidant N-acetylcysteine (NAC) supplementation to the parents alleviated TCS toxicity and improved immunological functions in the progeny, indicating the role of ROS in the TCS-induced multigenerational immune toxicity. This finding provides valuable insights into the potential immune risk of prenatal TCS exposure to their offspring in the higher organism.

Platelet-rich fibrin attenuates inflammation and fibrosis in vulvar lichen sclerosus via the TGF-β/SMAD3 pathway

Vulvar lichen sclerosus (VLS) is a chronic, inflammatory, and progressive skin disease mainly involved in the anogenital area. Platelet-rich fibrin (PRF) is a fibrin adhesive-concentrated platelet-rich plasma (PRP) used for tissue repair and angiogenesis. In this study, we explored the effects of PRF on VLS patients, further to utilize the established VLS animal model, to confirm the therapeutic effect of PRF and regulation on the TGF-β/SMAD3 pathway. Among the 46 VLS patients included in the analysis, injectable RPF (i-PRF) treatment improved the symptoms of VLS. The immunohistochemical analysis showed that i-PRF decreased the local blurring of the dermal-epidermal boundary and increased the number of basal keratinocytes. I-PRF increased positive PGD9.5, CD34, and Melan A cell numbers, and decreases positive IL-17 and INF-γ cell numbers in VLS tissues. In the VLS rat model, i-PRF reduced inflammatory factors IL-17 and INF-γ via inhibition of NF-κB and increased CD31 and VEGF expression in external genital tissue. The i-PRF decreases fibronectin and collagen-I by inhibiting TGF-β/SMAD3 in VLS, which is the main factor that triggers inflammation and fibrosis of the external genital skin.

Advancements in Green Nanoparticle Technology: Focusing on the Treatment of Clinical Phytopathogens

Opportunistic pathogenic microbial infections pose a significant danger to human health, which forces people to use riskier, more expensive, and less effective drugs compared to traditional treatments. These may be attributed to several factors, such as overusing antibiotics in medicine and lack of sanitization in hospital settings. In this context, researchers are looking for new options to combat this worrying condition and find a solution. Nanoparticles are currently being utilized in the pharmaceutical sector; however, there is a persistent worry regarding their potential danger to human health due to the usage of toxic chemicals, which makes the utilization of nanoparticles highly hazardous to eukaryotic cells. Multiple nanoparticle-based techniques are now being developed, offering essential understanding regarding the synthesis of components that play a crucial role in producing anti-microbial nanotherapeutic pharmaceuticals. In this regard, green nanoparticles are considered less hazardous than other forms, providing potential options for avoiding the extensive harm to the human microbiome that is prevalent with existing procedures. This review article aims to comprehensively assess the current state of knowledge on green nanoparticles related to antibiotic activity as well as their potential to assist antibiotics in treating opportunistic clinical phytopathogenic illnesses.

A deep-learning approach for identifying prospective chemical hazards

With the aim of helping to set safe exposure limits for the general population, various techniques have been implemented to conduct risk assessments for chemicals and other environmental stressors; however, none of these tools facilitate the identification of completely new chemicals that are likely hazardous and elicit an adverse biological effect. Here, we detail a novel in silico, deep-learning framework that is designed to systematically generate structures for new chemical compounds that are predicted to be chemical hazards. To assess the utility of the framework, we applied the tool to four endpoints related to environmental toxicants and their impacts on human and animal health: (i) toxicity to honeybees, (ii) immunotoxicity, (iii) endocrine disruption via ER-α antagonism, and (iv) mutagenicity. In addition, we characterized the predicted potency of these compounds and examined their structural relationship to existing chemicals of concern. As part of the array of emerging new approach methodologies (NAMs), we anticipate that such a framework will be a significant asset to risk assessors and other environmental scientists when planning and forecasting. Though not in the scope of the present study, we expect that the methodology detailed here could also be useful in the de novo design of more environmentally-friendly industrial chemicals.

Triclocarban evoked neutrophil extracellular trap formation in common carp (Cyprinus carpio L.) by modulating SIRT3-mediated ROS crosstalk with ERK1/2/p38 signaling

Triclocarban (TCC), an antimicrobial ingredient in personal care products, is associated with immunosuppression and physiological dysfunctions of aquatic organisms. The aim of this study was to investigate whether TCC can induce common carp NETosis (neutrophil death by neutrophil extracellular trap (NET) release) and then to attempt to identify the potential molecular mechanisms. Herein, scanning electron microscopy and flow cytometric assays showed that revealed that TCC triggers DNA-containing web-like structures and increases extracellular DNA content. In the proteomic analysis, we observed that NET-related proteins, extracellular regulated protein kinase (Mapk1, Mapk14, Jak2) and apoptotic protein (caspase3) were significantly increased, and defender against cell death 1 (Dad1) was significantly decreased after TCC treatments. Meanwhile, we confirmed that TCC stress can trigger NETosis in common carp by activating the reactive oxygen species (ROS)/ERK1/2/p38 signaling. We think that the upregulated NDUFS1 expression is closely related to oxidative stress induced by TCC. Importantly, we discovered that SIRT3 expression was significantly decreased in the process of TCC-induced NETs. Importantly, pretreatment with the SIRT3 agonist honokiol (HKL) effectively suppressed TCC-induced NET release. In contrast, the SIRT3 antagonist 3-TYP escalated TCC-induced NET formation. Mechanistically, SIRT3 degradation serves as a potential mediator for regulating oxidative stress crosstalk between ERK1/2/p38 signals in the process of TCC-induced NET formation. These findings unveil new insights into the TCC-evoked health risk of fish and other aquatic organisms and suggest that SIRT3 is a potential pharmacological intervention target to alleviate TCC-induced common carp NETosis.