Project description:Polystyrene (PS) is one of the most difficult plastics to degrade, and its microplastic residues have been detected in various environments.
Project description:The exposure to nano-plastics affects mammalian neurotoxic hazard characterization remains to be determined. Our aim was to investigate the neurotoxicity of nano-plastics in rodents. Animals were randomly divided into two groups: a control group and 50 mg/kg body weight PS NPs treatment groups. Before treatment, animals were fasted overnight. PS NPs were suspended into waters, vigorously stirred. The PS NPs via oral gavage once per day and for 6 months. The mice were treated with water in control group. We found that exposure to PS NPs caused cognitive decline. PS NPs exposure influenced the prefrontal cortex cells with more pathological alteration with increasing dosage. High-throughput RNA sequencing was conducted to explore miRNA expression in prefrontal cortex. Twenty-nine differentially expressed miRNAs were detected, including 12 upregulated and 17 downregulated miRNAs. This finding provided a reference for further studies on the development mechanisms of ncRNA during cognitive dysfunction.
Project description:The exposure to nano-plastics affects mammalian neurotoxic hazard characterization remains to be determined. Our aim was to investigate the neurotoxicity of nano-plastics in rodents. Animals were randomly divided into two groups: a control group and 50 mg/kg body weight PS NPs treatment groups. Before treatment, animals were fasted overnight. PS NPs were suspended into waters, vigorously stirred. The PS NPs via oral gavage once per day and for 6 months. The mice were treated with water in control group. We found that exposure to PS NPs caused cognitive decline. PS NPs exposure influenced the prefrontal cortex cells with more pathological alteration with increasing dosage. High-throughput RNA sequencing was conducted to explore miRNA expression in prefrontal cortex. Sixty-seven differentially expressed circRNAs were detected, including 25 upregulated and 42 downregulated circRNAs. We also explored 987 differentially expressed mRNAs, including 477 upregulated and 510 downregulated mRNAs.
Project description:This study focused on investigating the biocatalytic potential of the white-rot basidiomycete Abortiporus biennis LGAM 436 to modify the structure of different types of PS, including amorphous film with atactic stereochemistry and commercial EPS foam. The selection of this specific strain was mainly based on a previous report by our group, focusing on the isolation of a laccase secreted by A. biennis LGAM 436, which is capable of reducing the number-average molecular weight of PS by 20% (10.1016/j.chemosphere.2022.137338). To expedite the process of whole cell biocatalysis, we also evaluated the addition of the phenol-rich olive-oil mill wastewater effluent (OOMW); a byproduct which can act as an inducer of oxidative enzymes such as laccases and LiPs (10.1016/j.jenvman.2016.02.042). Following the assessment of PS degradation through analyses of molar mass, the emergence of new functional groups, and alterations in surface morphology, we sought to elucidate the enzymatic activities expressed in the presence of PS. This was achieved after the secretome assessment of the basidiomycete via proteomics studies, which will pave the way for the heterologous expression of novel enzymatic activities that can synergistically act to modify and degrade polyolefin structures.
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:Plastics are persistent synthetic polymers that accumulate in the marine environment as waste. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Filter-feeder organisms ingest MP while feeding and are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 32 µg L-1) for two months during a reproductive cycle. Effects were investigated on transcriptomic responses, in digestive gland gonads and oocytes of exposed oysters. Transcriptomic profiles in the tissues of the exposed oyster showed endocrine disrupting signals, notably highlighting alteration in glucocorticoid response, insulin pathway and fatty-acid metabolism in response to micro-PS exposition. In oocytes from exposed females, several transcripts coding for proteins involved in Ca2+ binding were differentially expressed suggesting a disruption of the Ca2+ signaling pathway with crucial consequences on oocyte maturation. To assess the impact of polystyrene microspheres (PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 32 µg L-1) for two months during a reproductive cycle and compared to control oysters. Adults were sampled 2 and 8 weeks after the beginning of exposure (corresponding to T1 and T3, respectively, 8-9 replicates per time of sampling and condition for a total of 56). Tissues were immediately dissected from each oyster, frozen in liquid nitrogen, then crushed to a fine powder at -196°C with an oscillating mill mixer and stored in liquid nitrogen until RNA extraction. Oocytes were collected from 5 females per condition, filtered in a 40 µm sieve, counted and transferred into 1.5 mL of Extract-all reagent (Eurobio, Courtaboeuf, France) (20,000 oocytes). Total RNA was isolated using 1.5 mL of Extract-all Reagent per 50 mg of gonad powder. For microarray hybridizations, 200 ng of total RNA were indirectly labeled with Cy3 using the Low Input Quick Amp Labeling kit One-Color. Hybridization was performed using the Agilent Gene expression hybridization kit (5188-5242), with 1.65 μg of labeled RNA, for 16 h at 65 °C. The employed arrays were Agilent 60-mer 4x44K custom microarrays, containing 31,918 C. gigas ESTs, designed by Dheilly et al. (2011). Slides were scanned on an Agilent Technologies G2565AA Microarray Scanner system at 5 μm resolution, using default parameters. Features were extracted using the Agilent Feature Extraction software 6.1.
Project description:Plastics are persistent synthetic polymers that accumulate in the marine environment as waste. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Filter-feeder organisms ingest MP while feeding and are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 32 µg L-1) for two months during a reproductive cycle. Effects were investigated on transcriptomic responses, in digestive gland gonads and oocytes of exposed oysters. Transcriptomic profiles in the tissues of the exposed oyster showed endocrine disrupting signals, notably highlighting alteration in glucocorticoid response, insulin pathway and fatty-acid metabolism in response to micro-PS exposition. In oocytes from exposed females, several transcripts coding for proteins involved in Ca2+ binding were differentially expressed suggesting a disruption of the Ca2+ signaling pathway with crucial consequences on oocyte maturation.
Project description:Human ingestion of microplastics (MPs) is common and inevitable due to the widespread contamination of food items, but implications on the gastric digestion of food proteins are still unknown. In this study, the interaction between pepsin and polystyrene (PS) MPs was uncovered by investigating its effect on enzyme activity and conformation while in a simulated human gastric environment. The impact on food digestion was also determined by monitoring the kinetics of protein hydrolysis through static in vitro gastric digestion of cow’s milk contaminated with PS. The binding of pepsin to PS showed that surface chemistry of MPs dictates binding affinity. The key contributor to pepsin adsorption seems to be π−π interactions between the aromatic residues and the PS phenyl rings. During quick exposure (10 minutes) of pepsin to increasing concentrations (222, 2219, 22188 particles/mL) of 10 μm PS (PS10) and 100 μm PS (PS100), total enzymatic activities were not affected remarkably. However, upon prolonged exposure at 1 and 2 hours, preferential binding of pepsin to the small, low zeta-potential PS caused structural changes in the protein which led to a significant reduction of its activity. Digestion of cow’s milk mixed with PS10 resulted in transient accumulation of larger peptides (10-35 kDa) and reduced bioavailability of short peptides (2-9 kDa) in the gastric phase. This, however, was only observed at extremely high PS10 concentration (0.3 mg/mL or 5.46E+05 particles/mL). The digestion of milk peptides, bound preferentially over pepsin on the hard corona around PS10, was delayed up to 15 minutes in comparison to bulk protein digestion. Intact caseins, otherwise rapidly digested, remained bound to PS10 in hard corona for up to 15 minutes. This work presents valuable insights regarding the interaction of MPs, food proteins, and pepsin, and their dynamics during gastric digestion which provides new knowledge and understanding on the potential risks of MPs to human health.
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:We found that compared to PS, SIS-PS modification increased the stemness, immunomodulatory capacity, and exosome secretion of UC-MSC, but decreased the resistance to stimuli.