Assessing the Impact of Polyethylene Nano/Microplastic Exposure on Human Vaginal Keratinocytes

Mechanism of Nano-Microplastics Exposure-Induced Myocardial Fibrosis: DKK3-Mediated Mitophagy Dysfunction and Pyroptosis

Nano-microplastics (NMPs), as environmental pollutants, are widely present in nature and pose potential threats to biological health. This study aims to investigate the mechanisms by which NMPs inhibit mitophagy through the suppression of dickkopf-related protein 3 (DKK3) expression, leading to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome-mediated cardiomyocyte pyroptosis and promoting myocardial fibrosis. Healthy adult male C57BL/6 mice were administered NMP solution via gavage, and their cardiac function was monitored. The results showed that NMP exposure significantly reduced left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) and increased the extent of myocardial fibrosis. Transcriptome sequencing identified 14 differentially expressed genes (DEGs), including MYL7. Using the random forest algorithm and functional enrichment analysis, DKK3 was identified as a key gene. In Vitro experiments further confirmed that NMPs downregulate DKK3 expression, thereby inhibiting mitophagy and promoting cardiomyocyte pyroptosis. This study elucidates the molecular mechanisms by which NMPs induce myocardial fibrosis and provides new theoretical bases and molecular targets for the diagnosis and treatment of heart diseases.

Effects of microplastics on the immune system: How much should we worry?

Plastics are everywhere. It is widely recognized that they represent a global problem, the extent of which is yet to be defined. Humans are broadly exposed to plastics, whose effects and consequences are poorly characterized so far. The main route of exposure is via alimentary and respiratory intake. Plastics pollutions may come from both: water and food contamination itself, and their packaging. The smaller sizes (i.e. microplastics <150 µm - MPs) are considered to be the most pervasive of living organisms and, therefore, potentially the most harmful. As humans occupy one of the apex positions of the food chain, we are exposed to bioaccumulation and biomagnification effects of MPs. In fact, MPs are commonly found in human stools and blood. However, there are no data available yet on their ability to accumulate and to produce detrimental consequences on biological systems. Even though the effects of plastics pollution are poorly studied in mammals, including humans, they appear to have inflammatory effects, which is rather concerning as many etiologies of disease are based on a pro-inflammatory status.

Nano-sized polystyrene plastics toxicity: Necroptosis pathway caused by autophagy blockade and lysosomal dysfunction

The persistent detection of nano-sized plastic particles in humans, animals, and animal-derived products underscores the potential impact of these particles on living organisms. Consequently, the toxicology of such particles has emerged as a pivotal research interests in recent years. In this study, NP was synthesized successfully with an average particle size of 100 nm using a emulsion polymerization method as model particles. Following co-incubation of IEC-6 cells with NP for 24-168 h, a notable inhibition of cell viability and proliferation was observed. The significant activation of autophagy and a concomitant blockage of autophagic flux in IEC-6 cells after 24-72 h of co-incubation with NP were unveiled by transmission electron microscopy, western blotting, and double-fluorescent autophagy analysis. A significant increase in the number of lysosomes and an increase in the expression of hydrolase CTSB were detected, indicating dysregulation of lysosomal function. The subsequent transcriptomic and metabolomics analyses, coupled with the observation of activated lysosomes and the RIPK1-RIPK3-MLKL/PYGL pathway, led us to posit that the blockade of autophagy and lysosomal dysfunction, culminating in lysosomal membrane permeabilization (LMP) induced necroptosis, constitutes one of the mechanisms contributing to the cytotoxicity of NP. SYNOPSIS: The cytotoxicity and its related mechanisms of nano-plastic is still unclear. This study found that nano-plastics may induce necroptosis in cells, and autophagy blockade and lysosomal dysfunction are prodromal manifestations.

Microplastics in the Human Body: Exposure, Detection, and Risk of Carcinogenesis: A State-of-the-Art Review

Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation.

Molecular and Cellular Effects of Microplastics and Nanoplastics: Focus on Inflammation and Senescence

Microplastics and nanoplastics (MNPs) are ubiquitous environmental contaminants. Their prevalence, persistence, and increasing industrial production have led to questions about their long-term impact on human and animal health. This narrative review describes the effects of MNPs on oxidative stress, inflammation, and aging. Exposure to MNPs leads to increased production of reactive oxygen species (ROS) across multiple experimental models, including cell lines, organoids, and animal systems. ROS can cause damage to cellular macromolecules such as DNA, proteins, and lipids. Direct interaction between MNPs and immune cells or an indirect result of oxidative stress-mediated cellular damage may lead to increased production of pro-inflammatory cytokines throughout different MNP-exposure conditions. This inflammatory response is a common feature in the pathogenesis of neurodegenerative, cardiovascular, and other age-related diseases. MNPs also act as cell senescence inducers by promoting mitochondrial dysfunction, impairing autophagy, and activating DNA damage responses, exacerbating cellular aging altogether. Increased senescence of reproductive cells and transfer of MNPs/induced damages from parents to offspring in animals further corroborates the transgenerational health risks of the tiny particles. This review aims to provoke a deeper investigation into the notorious effects these pervasive particles may have on human well-being and longevity.

Micro(nano)plastics: an Emerging Burden for Human Health

The escalation of plastic pollution represents a global environmental and health problem. Important toxic effects have been attributed to the increasing diffusion of microplastics (MPs) and nanoplastics (NPs) derived from the degradation of plastics. These particles have been ubiquitously observed in the environment, with humans being continuously exposed via ingestion, inhalation and skin contact. Nonetheless, the cellular homeostasis imbalance induced by micro- and nano- plastics (MNPs) in human health has been only recently shown, while most evidence and molecular mechanisms derived from studies in vitro and in vivo models. To date, the majority of available results testified the accumulation of MNPs in the cardiovascular, nervous, reproductive and digestive systems, and recently clear evidence about cardiovascular toxic effects of MNPs has been provided in humans. In this context, this review aims to provide a comprehensive update about the most recent studies reporting the effects of MNPs in different models, focusing on the available evidence in the main areas of study related to human health. Hopefully, this review will contribute to raise awareness about the toxicity and oxidative alteration exerted by MNPs, supporting the elaboration of new strategies to counteract plastic pandemics.

Health Implications of Widespread Micro- and Nanoplastic Exposure: Environmental Prevalence, Mechanisms, and Biological Impact on Humans

The increasing awareness of the potential health risks associated with microplastics' (MPs) and nanoplastics' (NPs) presence in the environment has led to a significant rise in research focused on these particles over the past few years. This review focuses on the research on MPs'/NPs' presence and spread, pathways of exposure, toxicological effects on human health and legal framework related to MP/NP challenges. Several research projects have aimed to assess their potential harm to human health, focusing on different systems and organs. After exposure (independent of the pathway), these hazards reach the blood stream and concentrate in different organs. Further, they are responsible for harmful changes, having an immediate effect (pain, inflammation, or hormone imbalance) or lead to a long-term disease (e.g., infertility, chronic obstructive pulmonary disease, or cancer). Toxicological effects have been noticed at high concentrations of MPs, specifically polystyrene, the most widespread typical MP, but only short-term effects have been mostly studied. Significant quantities of consumed MPs have been discovered to have diverse detrimental effects, posing a threat to human welfare. The exact concentrations of microplastics that are inhaled and swallowed and then build up in the human body are still not known. Further investigation is necessary to evaluate the impact of MP/NP contamination at minimal concentrations and for prolonged durations.

Polyethylene Micro/Nanoplastics Exposure Induces Epithelial-Mesenchymal Transition in Human Bronchial and Alveolar Epithelial Cells

Micro/nanoplastics (MNPs), which are widely spread in the environment, have gained attention because of their ability to enter the human body mainly through ingestion, inhalation, and skin contact, thus representing a serious health threat. Several studies have reported the presence of MNPs in lung tissue and the potential role of MNP inhalation in triggering lung fibrosis and tumorigenesis. However, there is a paucity of knowledge regarding the cellular response to MNPs composed of polyethylene (PE), one of the most common plastic pollutants in the biosphere. In this study, we investigated the effects of low/high concentrations of PE MNPs on respiratory epithelial cell viability and migration/invasion abilities, using MTT, scratch, and transwell assays. Morphological and molecular changes were assessed via immunofluorescence, Western blot, and qRT-PCR. We demonstrated that acute exposure to PE MNPs does not induce cellular toxicity. Instead, cells displayed visible morphological changes also involving actin cytoskeleton reorganization. Our data underlined the role of epithelial-mesenchymal transition (EMT) in triggering this process. Moreover, a remarkable increase in migration potential was noticed, in absence of a significant alteration of the cell's invasive capacity. The present study highlights the potential impact of PE MNPs inhalation on the human respiratory epithelium, suggesting a possible role in carcinogenesis.

Beyond microbeads: Examining the role of cosmetics in microplastic pollution and spotlighting unanswered questions

The presence of microplastics in cosmetics and personal care products (C&PCPs) has been increasingly in the public eye since the early 2010s. Despite increasing research into the potential environmental and health effects of microplastics, most research to date on microplastics in C&PCPs has investigated "rinse-off" products, while the potential impacts of "leave-on" C&PCPs have been largely neglected, despite these products being purchased in greater volumes and often having two or more microplastic ingredients in their formulations(CosmeticsEurope, 2018b). This review aims to synthesize the current knowledge of microplastic in C&PCPs, assessing the potential environmental and human health impacts of C&PCPs and discussing the regulatory implications. The lack of studies on leave-on C&PCPs is significant, suggesting a severe knowledge gap regarding microplastic presence in, and emissions from, C&PCPs. There is a noticeable lack of studies on the (eco)toxicological consequences of microplastic exposure from C&PCPs. As a result, significant aspects of microplastic contamination may be overlooked in the microplastic legislations emerging globally (including from the European Commission), which intend to restrict microplastic use in C&PCPs but focus on rinse-off C&PCPs only. This review highlights the potential consequences of microplastics in leave-on C&PCPs for regulatory decision-making, particularly as alternatives to microplastics are considered during the phase-out periods and spotlights the need for sufficient monitoring and research on these alternatives, to avoid unforeseen consequences.

Nano/micro-plastic, an invisible threat getting into the brain

Due to weather and working/operational conditions, plastic degradation produces toxic and non-biodegradable nano and microplastics (N/M-Ps, ranging from 10 nm to 5 mm), and over time these N/M-Ps have integrated with the human cycle through ingestion and inhalation. These N/M-Ps, as serious emerging pollutants, are causing considerable adverse health issues due to up-taken by the cells, tissue, and organs, including the brain. It has been proven that N/M-Ps can cross the blood-brain barrier (via olfactory and blood vessels) and affect the secretion of neuroinflammatory (cytokine and chemokine), transporters, and receptor markers. Neurotoxicity, neuroinflammation, and brain injury, which may result in such scenarios are a serious concern and may cause brain disorders. However, the related pathways and pathogenesis are not well-explored but are the focus of upcoming emerging research. Therefore, as a focus of this editorial, well-organized multidisciplinary research is required to explore associated pathways and pathogenesis, leading to brain mapping and nano-enabled therapeutics in acute and chronic N/M - Ps exposure.

Antitumour effects of SFX-01 molecule in combination with ionizing radiation in preclinical and in vivo models of rhabdomyosarcoma

BACKGROUND

Despite a multimodal approach including surgery, chemo- and radiotherapy, the 5-year event-free survival rate for rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in childhood, remains very poor for metastatic patients, mainly due to the selection and proliferation of tumour cells driving resistance mechanisms. Personalised medicine-based protocols using new drugs or targeted therapies in combination with conventional treatments have the potential to enhance the therapeutic effects, while minimizing damage to healthy tissues in a wide range of human malignancies, with several clinical trials being started. In this study, we analysed, for the first time, the antitumour activity of SFX-01, a complex of synthetic d, l-sulforaphane stabilised in alpha-cyclodextrin (Evgen Pharma plc, UK), used as single agent and in combination with irradiation, in four preclinical models of alveolar and embryonal RMS. Indeed, SFX-01 has shown promise in preclinical studies for its ability to modulate cellular pathways involved in inflammation and oxidative stress that are essential to be controlled in cancer treatment.

METHODS

RH30, RH4 (alveolar RMS), RD and JR1 (embryonal RMS) cell lines as well as mouse xenograft models of RMS were used to evaluate the biological and molecular effects induced by SFX-01 treatment. Flow cytometry and the modulation of key markers analysed by q-PCR and Western blot were used to assess cell proliferation, apoptosis, autophagy and production of intracellular reactive oxygen species (ROS) in RMS cells exposed to SFX-01. The ability to migrate and invade was also investigated with specific assays. The possible synergistic effects between SFX-01 and ionising radiation (IR) was studied in both the in vitro and in vivo studies. Student's t-test or two-way ANOVA were used to test the statistical significance of two or more comparisons, respectively.

RESULTS

SFX-01 treatment exhibited cytostatic and cytotoxic effects, mediated by G2 cell cycle arrest, apoptosis induction and suppression of autophagy. Moreover, SFX-01 was able to inhibit the formation and the proliferation of 3D tumorspheres as monotherapy and in combination with IR. Finally, SFX-01, when orally administered as single agent, displayed a pattern of efficacy at reducing the growth of tumour masses in RMS xenograft mouse models; when combined with a radiotherapy regime, it was observed to act synergistically, resulting in a more positive outcome than would be expected by adding each exposure alone.

CONCLUSIONS

In summary, our results provide evidence for the antitumour properties of SFX-01 in preclinical models of RMS tumours, both as a standalone treatment and in combination with irradiation. These forthcoming findings are crucial for deeper investigations of SFX-01 molecular mechanisms against RMS and for setting up clinical trials in RMS patients in order to use the SFX-01/IR co-treatment as a promising therapeutic approach, particularly in the clinical management of aggressive RMS disease.

The triple exposure nexus of microplastic particles, plastic-associated chemicals, and environmental pollutants from a human health perspective

The presence of microplastics (MPs) is increasing at a dramatic rate globally, posing risks for exposure and subsequent potential adverse effects on human health. Apart from being physical objects, MP particles contain thousands of plastic-associated chemicals (i.e., monomers, chemical additives, and non-intentionally added substances) captured within the polymer matrix. These chemicals are often migrating from MPs and can be found in various environmental matrices and human food chains; increasing the risks for exposure and health effects. In addition to the physical and chemical attributes of MPs, plastic surfaces effectively bind exogenous chemicals, including environmental pollutants (e.g., heavy metals, persistent organic pollutants). Therefore, MPs can act as vectors of environmental pollution across air, drinking water, and food, further amplifying health risks posed by MP exposure. Critically, fragmentation of plastics in the environment increases the risk for interactions with cells, increases the presence of available surfaces to leach plastic-associated chemicals, and adsorb and transfer environmental pollutants. Hence, this review proposes the so-called triple exposure nexus approach to comprehensively map existing knowledge on interconnected health effects of MP particles, plastic-associated chemicals, and environmental pollutants. Based on the available data, there is a large knowledge gap in regard to the interactions and cumulative health effects of the triple exposure nexus. Each component of the triple nexus is known to induce genotoxicity, inflammation, and endocrine disruption, but knowledge about long-term and inter-individual health effects is lacking. Furthermore, MPs are not readily excreted from organisms after ingestion and they have been found accumulated in human blood, cardiac tissue, placenta, etc. Even though the number of studies on MPs-associated health impacts is increasing rapidly, this review underscores that there is a pressing necessity to achieve an integrated assessment of MPs' effects on human health in order to address existing and future knowledge gaps.

Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles.

Polyethylene nanoplastics cause reproductive toxicity associated with activation of both estrogenic hormone receptor NHR-14 and DNA damage checkpoints in C. elegans

As the most commercial polymer, the polyethylene nanoparticle (PE-NP) has been discharged into the environment and poses potential risks to organisms. However, the possible reproductive toxicity of PE-NP and underlying mechanisms remain largely unknown. In this study, Caenorhabditis elegans was employed as the animal model to effects of PE-NP (100 nm) and their leachates on reproduction and underlying mechanisms. Nematodes were exposed to PE-NP at 0.1-100 μg/L from L1-larvae to adult day 1 (approximately 4.5 days). Both brood size and number of fertilized eggs in uterus were decreased by 10 and 100 μg/L PE-NP, but could not be affected by their leachates. In addition, number of mitotic cells, length, and area of gonad were reduced by 10 and 100 μg/L PE-NP, but were not altered by their leachates. Accompanied with alteration in expressions of genes (egl-1, ced-9, ced-4, and ced-3) governing cell apoptosis, germline apoptosis was enhanced by PE-NP. Meanwhile, DNA damage was involved in the enhancement germline apoptosis after PE-NP exposure. PE-NP further increased expression of nhr-14 encoding estrogenic hormone receptor, and RNAi of nhr-14 suppressed PE-NP reproductive toxicity. Moreover, RNAi of nhr-14 decreased expression of egl-1, ced-4, ced-3, and mrt-2 in PE-NP exposed nematodes. Therefore, exposure to PE-NPs rather than in their leachates potentially caused reproductive toxicity by activating both estrogenic hormone receptor NHR-14 and DNA damage checkpoints (CLK-2, HUS-1, and MRT-2) in nematodes. These findings provide important insights into the exposure risk of PE-NPs on reproduction of environmental organisms.

Adverse Effects of Micro- and Nanoplastics on Humans and the Environment

The pervasive pollution caused by nano- and microplastics (N/MPLs) is a pressing concern, and was exacerbated during the COVID-19 pandemic due to the substantial release of disposable Personal Protective Equipment (PPE) into the environment [...].