Project description:The widespread presence of microplastics (MPs) in freshwater systems has raised concerns about their potential ecotoxicity on aquatic organisms. In this study, we evaluated the effects of four MPs with different compositions, namely polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC) and polypropylene (PP), on freshwater microalgae Chlamydomonas reinhardtii. PS and PVC MPs caused greater growth inhibition and stronger oxidative stress response than PP and PE MPs. Proteomics analysis was employed to explore the mechanical understanding of the composition-dependent toxicity of MPs on microalgae. Proteins involved in photosynthesis processes were identified as contributors to the diverse responses of microalgae to differently composed MPs. Photosynthesis activity of algae, including pigment content and photoprotective response, was determined to reflect the distinct effect of the four MPs. The indicated down-regulated expression of photosynthetic proteins by proteomics analysis was further confirmed using western blot, with PVC and PS showing greater impacts on their expression reduction. Our findings not only show the composition-dependent effect of MPs on microalgae but also provide important insights into the molecular mechanism of MPs’ toxicity on natural phytoplankton species.
Project description:we studied the effect that 16.4 µm fragment type polypropylene (PP) MPs, which have an irregular shape and sharp edges and form naturally in the environment, had on breast cancer PPMP incubation for 24 hours in the MDA-MB-231 cells significantly altered the level of cell cycle-related transcripts in an RNA-seq analysis
Project description:Microplastics are defined as plastics ranging in size from 0.1μm to 5mm. Currently, research is being conducted across various fields to examine the effects of microplastics. Some studies demonstrated negative impacts on cells and mice. However, there is a lack of research on the effects by long-term exposure to microplastics. Most of the papers evaluated cytotoxicity with period of less than 2 months. Therefore, in this study, we investigated the potential issues that may arise from prolonged exposure through food mixed with Polypropylene microplastic (PP-MP) for over a year. We divided our study into short, mid, and long-term periods to assess cytotoxicity through Glucose tolerance test, Insulin tolerance test, analysis of insulin and c-peptide levels, hanging, grip, treadmill, Y-maze and open field tests, Respiratory Exchange Ratio, Energy Expenditure, Activity, and body composition. Through this, we comprehensively examined potential issues related to mouse behavior, muscle, metabolism and other factors. After dissection, RNA sequencing was carried out to investigate the effects on genes. For further verification, RT-qPCR was conducted. To summarize, our study provides evidence suggesting that treatment of microplastics for a short term has adverse effects, but with prolonged exposure, their effects tend to diminish.
Project description:Microplastics (MPs) as widespread contamination pose high risk for aquatic organisms.Intestinal microbiotahas have high interaction with immune system of host body. In this study, intestinal microbiota of zebrafish after Polystyrene (PS-MPs) exposure were characterized by 16S rDNA amplicon sequencing. We found that 100nm and 200μm PS-MPs exposure significantly increased diversity of intestinal microbiota and all the three sizes of PS-MPs increased abundance of pathogenic bacteria.
Project description:Microplastics (MPs) as widespread contamination pose high risk for aquatic organisms. However, current understanding of MP toxicities are based on cell population-averaged measurements. Here we used single-cell RNA sequencing to provide the transcriptome heterogeneity of 12000 intestinal cells obtained from zebrafishes exposed to 100nm, 5μm and 200μm polystyrene MPs (PS-MPs) for 21 days. Eight intestinal cell populations were identified. We found that all the three sizes of PS-MPs induced dysfunction of intestinal immune cells (including phagosome and regulation of immune system process).
Project description:Ingested microplastics (MPs) can accumulate throughout whole body, which may induce the dysfunction of immune system. However, it remains unclear how MP exposure affects innate immune responses at the cellular level. We found that mouse neutrophils strongly bind and then engulf polystyrene MPs. This interaction leads to proinflammatory state of neutrophils and eventually results in apoptotic cell death through toll-like receptor signaling pathway in a bacteria-recognition mimetic manner. Moreover, our data verified that orally administered polystyrene MPs reach various organs in mice, where they are interacted with and endocytosed by neutrophils. We confirmed that human neutrophils also strongly bind and internalize polystyrene MPs. Additionally, RNA sequencing analysis of polystyrene MPs-exposed human neutrophils showed the upregulation of cell death-related function. Therefore, the accumulated MPs may exacerbate inflammatory immune response by disrupting neutrophil function. These results provide novel insight into the adverse responses of neutrophils induced by MP exposure.
Project description:Microplastics (MPs) are considered as one of the main reasons for male and female infertility. However, the reproductive toxicity and its related mechanisms are understood by animal models with acute exposure to MPs at present. In the study, we show the low-dose polystyrene microplastics (PSMPs) exposure results in severely abnormal reproduction in female, but not male in mouse model, exhibiting failed oocyte meiotic maturation. Mechanistically, the PSMPs exposure induces the over-activation of cell metabolism pathways, insufficient HDACs and H4K16 hyperacetylation in oocytes in vivo and in vitro. By addition of HDAC3 inhibitor, the failed oocyte maturation, over-activation of cell metabolism pathways and H4K16 hyperacetylation are recapitulated, and the overexpression of HDAC3 can rescue the defects of meiotic maturation induced by PSMPs. Our observations suggest a direct link of the maturation defects induced by PSMPs to HDAC3 insufficiency. Thus, we propose the potential treatments for therapy of the failed meiotic maturation of oocyte from women highly exposed to MPs by activating or supplying HDAC3.
Project description:Microplastics are defined as plastics ranging in size from 0.1μm to 5mm. Currently, research is being conducted across various fields to examine the effects of microplastics. Some studies demonstrated negative impacts on cells and mice. However, there is a lack of research on the effects by long-term exposure to microplastics. Most of the papers evaluated cytotoxicity with period of less than 2 months. Therefore, in this study, we investigated the potential issues that may arise from prolonged exposure through food mixed with Polypropylene black microplastic (PB-MP) for over a year. We divided our study into short, mid, and long-term periods to assess cytotoxicity through Glucose tolerance test, Insulin tolerance test, analysis of insulin and c-peptide levels, hanging, grip, treadmill, Y-maze and open field tests, Respiratory Exchange Ratio, Energy Expenditure, Activity, and body composition. Through this, we comprehensively examined potential issues related to mouse behavior, muscle, metabolism and other factors. After dissection, RNA sequencing was carried out to investigate the effects on genes. For further verification, RT-qPCR was conducted. To summarize, our study provides evidence suggesting that treatment of microplastics for a short term has adverse effects, but with prolonged exposure, their effects tend to diminish.
Project description:Microplastics (MPs) have become a serious global environmental threat that causes damage to mammalian organs. In this work, we investigated the potential molecular mechanism underlying the development of liver fibrosis induced by long-term exposure to three different sized PS-MPs (80 nm, 0.5 µm and 5 µm) in mice. Liver fibrosis levels were evaluated in mice after chronic exposure to PS-MPs. Liver inflammation was mainly increased in chronic exposure to 80 nm and 0.5 µm PS-MPs. Liver lipid deposition was significantly enhanced after PS-MP exposure. However, oxidative stress was not changed under PS-MP exposure. GO enrichment and KEGG pathway analyses revealed that the DEGs and shared DEGs were mainly enriched in the metabolism of lipids. The mRNA expression levels of genes related to fatty acid oxidation, synthesis and transport were dramatically induced by PS-MP exposure. Four hub genes, Acot3, Abcc3, Nr1i3 and Fmo2, were identified by CytoHubba analysis of shared DEGs. The mRNA expression levels of three hub genes, Acot3, Abcc3 and Nr1i3, were significantly augmented under chronic PS-MP exposure. Our results suggest that Acot3, Abcc3 and Nr1i3 are potential molecules involved in the development of liver fibrosis under chronic exposure to PS-MPs.
Project description:Peyer’s patches (PP) are primary inductive sites of mucosal immunity. Defining PP mononuclear phagocyte system (MPS) is thus crucial to understand the initiation of mucosal immune response. We provide a comprehensive analysis of the phenotype, distribution, ontogeny, lifespan, function and transcriptional profile of PP MPS. We show that monocytes give rise to macrophages and to lysozyme-expressing DC (LysoDC) which are both involved in particulate antigen uptake, display strong innate antiviral and antibacterial gene signatures and, upon TLR7 stimulation, secrete IL-6 and TNF but no IL-10. However, unlike macrophages, LysoDC display a rapid renewal rate, strongly express genes of the MHCII presentation pathway and prime naïve helper T cells for IFNg production. Our results show that in PP, at steady state, monocytes generate both LysoDC and macrophages which display distinct features from their adjacent villus counterparts.