Ubiquitous contamination of microplastics and arsenic in soil ecosystems can induce many health issues to nontarget soil organisms, and will also cause many potential threats to the gut bacterial ...communities of soil fauna. However, the changes in the gut bacterial communities of soil fauna after exposure to both microplastics and arsenic remain unknown. In this study, the toxicity and effects on the gut microbiota of earthworm Metaphire californica caused by the combined exposure of microplastics and arsenic were examined by using arsenic species analysis and high throughput sequencing of gut microbiota. Results showed that total arsenic and arsenic species in the earthworm gut and body tissues after exposure to combination of microplastics with arsenate (As(V)) were significantly different from that treated with As(V) alone. Microplastics lessened the accumulation of total arsenic and the transformation rate of As(V) to arsenite (As(III)). Microplastics alleviated the effect of arsenic on the gut microbiota possibly via adsorbing/binding As(V) and lowering arsenic bioavailability, thus prevented the reduction of As(V) and accumulation of total arsenic in the gut which resulted in a lower toxicity on the earthworm. The study broadens our understanding of the ecotoxicity of microplastics with other pollutants on the soil animals and on their gut microbiota.
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•Arsenic exposure prominently altered the gut bacterial communities of earthworm.•Microplastics reduced arsenic accumulation in the earthworm gut and body tissues by inhibiting As(V) reduction.•Microplastics alleviated the effect of arsenic on the gut microbiota.
Exposure to microplastics lowers arsenic accumulation in the gut and body tissues of earthworm, and alters gut bacterial communities of Metaphire californica.
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Endochondral bone formation is largely dependent on cartilage lineage cells. The chondrocytes in growth plates continuously undergo a sequential process from proliferation to terminal ...hypertrophic differentiation 1 . Once differentiated, hypertrophic chondrocytes elicit multiple functions such as determining bone length, inducing osteogenesis as well as directing bone mineralization, and eventually disappear at the chondro-osseous junction.
The biotransformation of arsenic is highly relevant to the arsenic biogeochemical cycle. Identification of the molecular details of microbial pathways of arsenic biotransformation coupled with ...analyses of microbial communities by meta-omics can provide insights into detailed aspects of the complexities of this biocycle. Arsenic transformations couple to other biogeochemical cycles, and to the fate of both nutrients and other toxic environmental contaminants. Microbial redox metabolism of iron, carbon, sulfur, and nitrogen affects the redox and bioavailability of arsenic species. In this critical review we illustrate the biogeochemical processes and genes involved in arsenic biotransformations. We discuss how current and future metagenomic-, metatranscriptomic-, metaproteomic-, and metabolomic-based methods will help to decipher individual microbial arsenic transformation processes, and their connections to other biogeochemical cycle. These insights will allow future use of microbial metabolic capabilities for new biotechnological solutions to environmental problems. To understand the complex nature of inorganic and organic arsenic species and the fate of environmental arsenic will require integrating systematic approaches with biogeochemical modeling. Finally, from the lessons learned from these studies of arsenic biogeochemistry, we will be able to predict how the environment changes arsenic, and, in response, how arsenic biotransformations change the environment.
High glucose (HG) is one of the basic factors of diabetic nephropathy (DN), which leads to high morbidity and disability. During DN, the expression of glomerular glucose transporter 1 (GLUT1) ...increases, but the relationship between HG and GLUT1 is unclear. Glomerular mesangial cells (GMCs) have multiple roles in HG‐induced DN. Here, we report prominent glomerular dysfunction, especially GMC abnormalities, in DN mice, which is closely related to GLUT1 alteration. In vivo studies have shown that BBR can alleviate pathological changes and abnormal renal function indicators of DN mice. In vitro, BBR (30, 60 and 90 μmol/L) not only increased the proportion of G1 phase cells but also reduced the proportion of S phase cells under HG conditions at different times. BBR (60 μmol/L) significantly reduced the expression of PI3K‐p85, p‐Akt, p‐AS160, membrane‐bound GLUT1 and cyclin D1, but had almost no effect on total protein. Furthermore, BBR significantly declined the glucose uptake and retarded cyclin D1‐mediated GMC cell cycle arrest in the G1 phase. This study demonstrated that BBR can inhibit the development of DN, which may be due to BBR inhibiting the PI3K/Akt/AS160/GLUT1 signalling pathway to regulate HG‐induced abnormal GMC proliferation and the cell cycle, supporting BBR as a potential therapeutic drug for DN.
Over 300 species of naturally occurring-organoarsenicals have been identified with the development of modern analytical techniques. Why there so many environmental organoarsenicals exist is a real ...enigma. Are they protective or harmful? Or are they simply by-products of existing pathways for non-arsenical compounds? Fundamental unanswered questions exist about their occurrence, prevalence and fate in the environment, metabolisms, toxicology and biological functions. This review focuses on possible answers. As a beginning, we classified them into two categories: water-soluble and lipid-soluble organoarsenicals (arsenolipids). Continual improvements in analytical techniques will lead to identification of additional organoarsenicals. In this review, we enumerate identified environmental organoarsenicals and speculate about their pathways of synthesis and degradation based on structural data and previous studies. Organoarsenicals are frequently considered to be nontoxic, yet trivalent methylarsenicals, synthetic aromatic arsenicals and some pentavalent arsenic-containing compounds have been shown to be highly toxic. The biological functions of some organoarsenicals have been defined. For example, arsenobetaine acts as an osmolyte, and membrane arsenolipids have a phosphate-sparing role under phosphate-limited conditions. However, the toxicological properties and biological functions of most organoarsenicals are largely unknown. The objective of this review is to summarize the toxicological and physiological properties and to provide novel insights into future studies.
Arsenic biotransformation mediated by gut microbiota can affect arsenic bioavailability and microbial community. Arsenic species, arsenic biotransformation genes (ABGs), and the composition of gut ...microbial community were characterized after the earthworm Metaphire sieboldi was cultured in soils spiked with different arsenic concentrations. Arsenite (As(III)) was the major component in the earthworm gut, whereas arsenate (As(V)) was predominant in the soil. A total of 16 ABGs were quantified by high-throughput quantitative polymerase chain reaction (HT-qPCR). Genes involved in arsenic redox and efflux were predominant in all samples, and the abundance of ABGs involved in arsenic methylation and demethylation in the gut was very low. These results reveal that the earthworm gut can be a reservoir of microbes with the capability of reducing As(V) and extruding As(III) but with little methylation of arsenic. Moreover, gut microbial communities were dominated by Actinobacteria, Firmicutes, and Proteobacteria at the phylum level and were considerably different from those in the surrounding soil. Our work demonstrates that exposure to As(V) disturbs the gut microbiota of earthworms and provides some insights into arsenic biotransformation in the earthworm gut.
Combinations of metal(loid) contamination and antibiotics are considered to increase the abundance of resistance genes in the environment, whereas the combined effect of metal(loid)s and ...antibiotics on microbial communities and antibiotic resistance genes (ARGs) in the gut of soil fauna remains unknown. We investigated herein the alteration of ARGs and the gut microbial communities after the earthworm Metaphire sieboldi was exposed to arsenate and/or sulfamethoxazole using high-throughput quantitative PCR and Illumina sequencing analysis. Arsenic accumulation in the body tissues of arsenic-exposed earthworms exerted a significant inhibition on growth and survival. The synergistic interactions of arsenic and sulfamethoxazole increased significantly the incidence of ARGs and mobile genetic elements in the earthworm gut microbiota. In addition, co-exposure to arsenic and sulfamethoxazole altered the structure of the gut microbial communities, and the changes correlated with ARG profiles of the gut microbiota. Our results indicate that the gut of soil fauna is a neglected hotspot of antibiotic resistance.
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•Soil and antibiotic co-exposure reshaped mouse gut microbiota and metabolic profile.•Antibiotic co-exposure decreased As accumulation in mouse kidneys and excretion in urine.•Soil ...bioavailable As pool in the intestinal tract decreased due to reduced amino acids.•Transformation from inorganic to organic As was enhanced by the antibiotic perturbed microbiota.•Gut microbiota and metabolites played an important role in soil-borne As bioavailability.
Oral bioavailability of arsenic (As) determines levels of As exposure via ingestion of As-contaminated soil, however, the role of gut microbiota in As bioavailability has not evaluated in vivo although some in vitro studies have investigated this. Here, we made a comparison in As relative bioavailability (RBA) estimates for a contaminated soil (3913 mg As kg−1) using a mouse model with and without penicillin perturbing gut microbiota and metabolites. Compared to soil exposure alone (2% w/w soil in diets), addition of penicillin (100 or 1000 mg kg−1) reduced probiotic Lactobacillus and sulfate-reducing bacteria Desulfovibrio, enriched penicillin-resistant Enterobacter and Bacteroides, and decreased amino acid concentrations in ileum. With perturbed gut microbiota and metabolic profile, penicillin and soil co-exposed mice accumulated 2.81–3.81-fold less As in kidneys, excreted 1.02–1.35-fold less As in urine, and showed lower As-RBA (25.7–29.0%) compared to mice receiving diets amended with soil alone (56 ± 9.63%). One mechanism accounted for this is the decreased concentrations of amino acids arising from the gut microbiota shift which resulted in elevated iron (Fe) and As co-precipitation, leading to reduced As solubilization in the intestine. Another mechanism was conversion of bioavailable inorganic As to less bioavailable monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) by the antibiotic perturbed microflora. Based on in vivo mouse model, we demonstrated the important role of gut microbiota and gut metabolites in participating soil As solubilization and speciation transformation then affecting As oral bioavailability. Results are useful to better understand the role of gut bacteria in affecting As metabolism and the health risks of As-contaminated soils.
This study aimed to investigate the characteristics and mechanism of autophagy on podocyte apoptosis under high glucose (HG) conditions and further explore the effect of berberine on podocyte ...autophagy, apoptosis and the potential mechanism.
The levels of LC3II/I in podocytes stimulated with HG were detected at 0, 2, 4, 8, 12, 24, 36 and 48 h by western blotting. CCK-8 was used to detect the viability of podocytes. The level of autophagy was detected by western blotting, transmission electron microscopy and immunofluorescence. Podocyte apoptosis was analysed by using Hoechst staining, western blotting, annexin V/propidium iodide dual staining, and confocal microscopy. Then, podocytes were transfected with siRNA to silence mTOR, and the expression levels of proteins and mRNA involved in the mTOR/P70S6K/4EBP1 pathway were further investigated by western blotting and qRT-PCR.
In this study, we found significantly reduced LC3II/LC3I and increased p62 in podocytes stimulated with HG for 24 h, and the level of autophagy reached a minimum at 24 h. Berberine restored podocyte viability and significantly attenuated HG-mediated inhibition of autophagy, as evidenced by the increased expression of LC3II/LC3I, the number of autophagosomes and the inhibition of p62. Moreover, berberine counteracted HG-induced podocyte apoptosis and injury, which was negatively correlated with the autophagy effect. Notably, silencing mTOR with siRNA augmented the inhibition of P70S6k and 4EBP1 phosphorylation, which was similar to the effect of berberine.
Berberine activates podocyte autophagy by inhibiting the mTOR/P70S6K/4EBP1 signaling pathway, thereby alleviating podocyte apoptosis.
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•Co-exposure to high copper and tetracycline increased the abundance of ARGs in the mouse guts.•Abnormal copper and/or tetracycline exposure significantly affected the community ...structure of the mouse gut microbiota.•Abnormal intake of copper and/or tetracyclines increased the enrichment of potential pathogens in the mouse guts and the pathogenic risk to public health.
The widespread use of copper and tetracycline as growth promoters in the breeding industry poses a potential threat to environmental health. Nevertheless, to the best of our knowledge, the potential adverse effects of copper and tetracycline on the gut microbiota remain unknown. Herein, mice were fed different concentrations of copper and/or tetracycline for 6 weeks to simulate real life–like exposure in the breeding industry. Following the exposure, antibiotic resistance genes (ARGs), potential pathogens, and other pathogenic factors were analyzed in mouse feces. The co-exposure of copper with tetracycline significantly increased the abundance of ARGs and enriched more potential pathogens in the gut of the co-treated mice. Copper and/or tetracycline exposure increased the abundance of bacteria carrying either ARGs, metal resistance genes, or virulence factors, contributing to the widespread dissemination of potentially harmful genes posing a severe risk to public health. Our study provides insights into the effects of copper and tetracycline exposure on the gut resistome and potential pathogens, and our findings can help reduce the risks associated with antibiotic resistance under the One Health framework.
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