Effects of Micro(nano)plastics on the reproductive system: A review

Melatonin prevents the transgenerational toxicity of nanoplastics in zebrafish (Danio rerio)

As a novel pollutant, microplastic pollution has become a global environmental concern. Melatonin (MT) has a protective effect on the damage caused by pollutants. However, there is still a lack of research on the transgenerational toxicity of microplastics and the alleviation of microplastics toxicity by MT. In this study, the adult zebrafish was exposed to (0, 0.1 and 1 mg/L) polystyrene nanoplastics (PSNP) with or without (1 μM) MT for 14 days, and embryos (F1) were used for experiments. Our study found that long-term exposure of parents to 1 mg/L PSNP reduced fertilization rate and survival rate of offspring, increased the deformity rate and induced embryos to hatch in advance. The growth inhibition of offspring was related to the gene transcription of the growth hormone/insulin-like growth factor axis. Moreover, PSNP caused oxidative stress in offspring, damaged immune system, reduced antioxidant capacity and induced apoptosis. MT supplementation could effectively alleviate the developmental toxicity and oxidative damage of offspring, but the negative effects brought by PSNP could not be completely eliminated. Our research provided a new reference for the protective effect of MT on transgenerational toxicity induced by PSNP.

Nasal instillation of polystyrene nanoplastics induce lung injury via mitochondrial DNA release and activation of the cyclic GMP-AMP synthase-stimulator of interferon genes-signaling cascade

Nanoplastics (NPs) are a common type of degraded plastic material associated with adverse health effects such as pulmonary injury. However, the molecular mechanism(s) underlying lung injury as caused by NPs remains uncertain. Thus, we herein investigated the pulmonary toxicity of NPs on RAW264.7 cells and C57BL/6 mice. Our in vitro study indicated that NPs induced oxidative stress, cell death, inflammation, and the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-signaling pathway. Mice in our in vivo study displayed significant pulmonary fibrosis, inflammation, apoptosis, necrosis, and excessive double-stranded DNA release into serum and bronchoalveolar lavage fluid. Our mechanistic exploration uncovered cGAS-STING-signaling activation as the leading cause of NPs-induced pulmonary fibrosis. The current study opens an avenue toward elucidating the role of the cGAS-STING-signaling pathway in NPs-induced pulmonary injury.

Microplastic from beach sediment to tissue: a case study on burrowing crab Dotilla blanfordi

Background

Microplastics (MPs) are pervasive pollutants in the marine environment, exhibiting persistence in coastal sediment over extended periods. However, the mechanism of their uptake by marine organisms and distribution in habitat is less understood. The objective of the present study was to investigate the presence of MP contamination in burrow sediment, feeding pellets, and tissue of Dotilla blanfordi in the Gulf of Kachchh, Gujarat State.

Methods

A total of 500 g of burrow sediment, 100 g of feeding pellets, and body tissue of 10 resident D. blanfordi were pooled as one replica. Such seven replicas from each site were analyzed for MP extraction from three sites, including Asharmata, Mandvi, and Serena, located in the Gulf of Kachchh. The standard protocol was used during the analysis of the collected samples in order to isolate MPs.

Results

The abundance of MP was found higher in burrow sediment, feeding pellets and tissue of D. blanfordi at study site Mandvi, followed by Serena and Asharmata. The abundance of MP was found higher in D. blanfordi tissue, followed by burrow sediment and feeding pellet. A significant variation was observed in MP abundance among burrow sediment, feeding pellets, and tissue. MPs with various shapes (fiber, film, and fragment), sizes (1-2, 2-3, 3-4, and 4-5 mm), and colors (blue, green, black, pink, purple, red transparent) were recorded from all the study sites. Polyurethane and polyvinyl chloride were recognized as the chemical profile of the extracted MPs. The current investigation revealed greater accumulation of MPs in D. blanfordi's tissues compared to sediment and pellets, suggesting a risk of MP contamination in marine benthic fauna with a greater rate of bioaccumulation. D. blanfordi plays a significant role as a structuring agent for MP distribution in the intertidal flat through burrowing activity.

Exploring developmental toxicity of microplastics and nanoplastics (MNPS): Insights from investigations using zebrafish embryos

Microplastics and nanoplastics (MNPs) have received increasing attention due to their high detection rates in human matrices and adverse health implications. However, the toxicity of MNPs on embryo/fetal development following maternal exposure remains largely unexplored. Zebrafish, sharing genetic similarities with human, boast a shorter life cycle, rapid embryonic development, and the availability of many transgenic strains, is a suitable model for environmental toxicology studies. This review comprehensively explores the existing research on the impacts of MNPs on zebrafish embryo development. MNPs exposure induces a wide array of toxic effects, encompassing neurodevelopmental toxicity, immunotoxicity, gastrointestinal effects, microbiota dysbiosis, cardiac dysfunctions, vascular toxicity, and metabolic imbalances. Moreover, MNPs disrupt the balance between reactive oxygen species (ROS) production and antioxidant capacity, culminating in oxidative damage and apoptosis. This study also offers insight into the current omics- and multi-omics based approaches in MNPs research, which greatly expedite the discovery of biochemical or metabolic pathways, and molecular mechanisms underlying MNPs exposure. Additionally, this review proposes a preliminary adverse outcome pathway framework to predict developmental toxicity caused by MNPs. It provides a comprehensive overview of pathways, facilitating a clearer understanding of the exposure and toxicity of MNPs, from molecular effects to adverse outcomes. The compiled data in this review provide a better understanding for MNPs effects on early life development, with the goal of increasing awareness about the risks posed to pregnant women by MNPs exposure and its potential impact on the health of their future generations.

Research Progress on Micro(nano)plastic-Induced Programmed Cell Death Associated with Disease Risks

Due to their robust migration capabilities, slow degradation, and propensity for adsorbing environmental pollutants, micro(nano)plastics (MNPs) are pervasive across diverse ecosystems. They infiltrate various organisms within different food chains through multiple pathways including inhalation and dermal contact, and pose a significant environmental challenge in the 21st century. Research indicates that MNPs pose health threats to a broad range of organisms, including humans. Currently, extensive detection data and studies using experimental animals and in vitro cell culture indicate that MNPs can trigger various forms of programmed cell death (PCD) and can induce various diseases. This review provides a comprehensive and systematic analysis of different MNP-induced PCD processes, including pyroptosis, ferroptosis, autophagy, necroptosis, and apoptosis, based on recent research findings and focuses on elucidating the links between PCD and diseases. Additionally, targeted therapeutic interventions for these diseases are described. This review provides original insights into the opportunities and challenges posed by current research findings. This review evaluates ways to mitigate various diseases resulting from cell death patterns. Moreover, this paper enhances the understanding of the biohazards associated with MNPs by providing a systematic reference for subsequent toxicological research and health risk mitigation efforts.

Luteolin: A promising multifunctional natural flavonoid for human diseases

Natural products are closely associated with human health. Luteolin (LUT), a flavonoid polyphenolic compound, is widely found in fruits, vegetables, flowers, and herbs. It is noteworthy that LUT exhibits a variety of beneficial pharmacological properties and holds significant potential for clinical applications, particularly in antitumor, anti-convulsion, diabetes control, anti-inflammatory, neuroprotection, anti-oxidation, anti-cardiovascular, and other aspects. The potential mechanism of action has been partially elucidated, including the mediation of NF-κB, toll-like receptor, MAPK, Wnt/β-catenin, PI3K/Akt, AMPK/mTOR, and Nrf-2, among others. The review that aimed to comprehensively consolidate essential information on natural sources, pharmacological effects, therapeutic and preventive potential, as well as potential mechanisms of LUT. The objective is to establish a theoretical basis for the continued development and application of LUT.

Adverse effects and potential mechanisms of polystyrene microplastics (PS-MPs) on the blood-testis barrier

Microplastics (MPs) are defined as plastic particles or fragments with a diameter of less than 5 mm. These particles have been identified as causing male reproductive toxicity, although the precise mechanism behind this association is yet to be fully understood. Recent research has found that exposure to polystyrene microplastics (PS-MPs) can disrupt spermatogenesis by impacting the integrity of the blood-testis barrier (BTB), a formidable barrier within mammalian blood tissues. The BTB safeguards germ cells from harmful substances and infiltration by immune cells. However, the disruption of the BTB leads to the entry of environmental pollutants and immune cells into the seminiferous tubules, resulting in adverse reproductive effects. Additionally, PS-MPs induce reproductive damage by generating oxidative stress, inflammation, autophagy, and alterations in the composition of intestinal flora. Despite these findings, the precise mechanism by which PS-MPs disrupt the BTB remains inconclusive, necessitating further investigation into the underlying processes. This review aims to enhance our understanding of the pernicious effects of PS-MP exposure on the BTB and explore potential mechanisms to offer novel perspectives on BTB damage caused by PS-MPs.

New insights into the spleen injury by mitochondrial dysfunction of chicken under polystyrene microplastics stress

Microplastics biological toxicity, environmental persistence and biological chemicals have been paid widespread attention. Microplastics exposed to chicken spleen injury of the specific mechanism is unclear. Thus, we randomly assigned chickens to 4 groups: C (normal diet), L-MPs (1 mg/L), M-MPs (10 mg/L), and H-MPs (100 mg/L), and assessed spleen damage after 42 d of exposure. Morphologically, the boundary between the red and white pulp of the spleen was blurred, along with the expansion of the white pulp. It was further speculated that microplastics induced mitochondrial dynamic homeostasis (Drp1 upgraded, Mfn1, Mfn2, and OPA1 reduced), and provoked the mitochondrial apoptotic pathway (Bcl-2/Bax decreased, cytc, caspase3, and caspase9 raised), resulting in redox imbalance and lipid peroxide accumulation (MDA increased, CAT, GSH, and T-AOC plummeted), and further stimulated ferroptosis (FTH1, GPX4, and SLC7A11 decreased). Here we explored the impact of polystyrene microplastics on the spleen, as well as the programmed death (apoptosis and ferroptosis) involved, and the regulative role of mitochondria in this process. This could be of significant importance in bridging the gap in laboratory research on microplastics-induced spleen injury in chicken.

Microplastics in maternal amniotic fluid and their associations with gestational age

Microplastics (MPs) pollution is a growing global concern due to its potential threat to human health, particularly concerning fetal health. Nevertheless, few studies have examined the sources of fetal MPs exposure and its impact on fetal development. In this study, MPs levels in maternal amniotic fluid (AF) and their associations with measures of fetal growth were investigated. Specifically, 40 human AF samples were collected to determine the presence and characteristics of MPs using laser direct infrared (LD-IR) spectroscopy. MPs were found in 32 out of 40 AF samples, with an average abundance of 2.01 ± 4.19 particles/g. Polyethylene (PE, 38.80 %) and chlorinated polyethylene (CPE, 26.98 %) were the most prevalent polymers. The majority of MPs (87.56 %) were 20-100 μm in size, and fragments (71.23 %) evidently prevailed in morphology. Additionally, a questionnaire was designed to explore the associations between MPs levels in the AF and maternal dietary habits, aiming at unveiling the potential sources of MPs in AF. The MPs levels in the AF were positively associated with the frequency of seafood consumption (r = 0.781, P < 0.001) and bottled water intake (r = 0.386, P = 0.014). Moreover, the associations between MPs levels in maternal AF and measures of fetal growth were evaluated. The abundance of total MPs in maternal AF were significantly negatively associated with gestational age (β = -0.44, 95 % CI, -0.83, -0.05). This study confirms the presence of MPs in human AF and provides compelling evidence linking them to gestational age, while highlighting the potential risks associated with dietary habits. These findings underscore the need for further investigation into the mechanisms of MPs transmission from mother to fetus and the potential health implications during fetal development, offering valuable insights for future policies aimed at safeguarding maternal and fetal health.

Abundance and distribution of marine litter on the beaches of Okinawa Island, Japan

This study evaluated the distribution and abundance of marine litter on 30 beaches around Okinawa Island, Japan. Beach quality indices and multivariate statistical analyses were used to assess the quality of the beaches and their pollution patterns. A total of 11,626 items weighing 513.49 kg with an average density of 0.13 ± 0.10 items/m2 were collected. Litter was dominated by plastics (81.72 %), broken glass (8.38 %), and cigarette butts (7.44 %), and 74.05 % of total litter was from land-based sources. Single-use plastics (SUPs) were present in all surveyed beaches and made up 30.54 % of the total litter. The clean coast index (CCI), plastic abundance index (PAI), and hazardous index (HI) were between 0.1 and 7.6, 0.1-4.0 and 0.01-1.42, respectively, indicating low to moderate levels of pollution of Okinawan beaches. This study should aid in the formation of strategies to deal with marine litter in Okinawa, other areas of Japan and the Asia-Pacific region.

Intracellular Protein Adsorption Behavior and Biological Effects of Polystyrene Nanoplastics in THP-1 Cells

Micro(nano)plastics (MNPs) are emerging pollutants that can adsorb pollutants in the environment and biological molecules and ultimately affect human health. However, the aspects of adsorption of intracellular proteins onto MNPs and its biological effects in cells have not been investigated to date. The present study revealed that 100 nm polystyrene nanoplastics (NPs) could be internalized by THP-1 cells and specifically adsorbed intracellular proteins. In total, 773 proteins adsorbed onto NPs with high reliability were identified using the proteomics approach and analyzed via bioinformatics to predict the route and distribution of NPs following cellular internalization. The representative proteins identified via the Kyoto Encyclopedia of Genes and Genomes pathway analysis were further investigated to characterize protein adsorption onto NPs and its biological effects. The analysis revealed that NPs affect glycolysis through pyruvate kinase M (PKM) adsorption, trigger the unfolded protein response through the adsorption of ribophorin 1 (RPN1) and heat shock 70 protein 8 (HSPA8), and are chiefly internalized into cells through clathrin-mediated endocytosis with concomitant clathrin heavy chain (CLTC) adsorption. Therefore, this work provides new insights and research strategies for the study of the biological effects caused by NPs.