Hydrophobic organic contaminants affiliated with polymer-specific microplastics in urban river tributaries and estuaries.

Exposure to microplastics (MPs) and hydrophobic organic contaminants (HOCs) combined at high concentrations may induce adverse effects to aquatic organisms in laboratory-scale studies. To determine environmentally relevant concentrations of HOCs in MPs, it is essential to understand the occurrence of MP-affiliated HOCs in the aquatic environment. Here we report the occurrences of HOCs affiliated with polymer-specific floating MPs from 12 tributaries and three estuaries in the Pearl River Delta, South China. Target HOCs include nine synthetic musks (SMs), 14 ultraviolet adsorbents (UVAs), 15 polycyclic aromatic hydrocarbons (PAHs), eight polybrominated diphenyl ethers (PBDEs), and 14 polychlorinated biphenyls (PCBs). Average concentrations of MP-affiliated ∑9SM, ∑14UVA, ∑15PAH, ∑8PBDE, and ∑14PCB were 1790, 5550, 1090, 412, and 107 ng g-1, respectively. The average concentrations of HOCs affiliated with MPs of different polymer types were 9790, 7220, 72,500, and 55,800 ng g-1 for polyethylene (PE), polypropylene, polystyrene, and other MPs, respectively. As the concentration of PE was the highest among all MPs at the average concentration of 0.77 mg m-3, the monthly outflow of PE-affiliated HOCs accounted for the largest proportion (46 %) in the outflow of MP-affiliated HOCs (2.8 g) to the coastal ocean via three estuaries. These results suggest that HOCs were highly concentrated in MPs and varied among different chemicals and polymer types. Due to the differences of polymer characteristics and half-life of affiliated chemicals, future toxicology studies concerning exposure to these combined pollutants may need to specify polymer types and their affiliated chemicals.

Artificial Cells for Cellular Behavior Mimicry Induced by Sphingomyelin Degradation.

Sphingomyelinase (SMase), a hydrolase of sphingomyelin (SM) enriched in the outer leaflet of the plasma membrane of mammalian cells, is closely associated with the onset and development of many diseases, but the specific mechanisms of SMase on the cell structure, function, and behavior are not yet fully understood due to the complexity of the cell structure. Artificial cells are minimal biological systems constructed from various molecular components designed to mimic cellular processes, behaviors, and structures, which are excellent models for studying biochemical reactions and dynamic changes in cell membranes. In this work, we presented an artificial cell model that mimics the lipid composition and content of the outer leaflet of mammalian plasma membranes for studying the effect of SMase on cell behavior. The results confirmed that the artificial cells can respond to SM degradation by producing ceramides that enrich and alter the membrane charge and permeability, thus inducing the budding and fission of the artificial cells. Thus, the artificial cells developed here provide a powerful tool to study the mechanism of action of cell membrane lipids on cell biological behavior, paving the way for further molecular mechanism studies.

Inducing Autophagy and Blocking Autophagic Flux via a Virus-Mimicking Nanodrug for Cancer Therapy.

Maximizing the therapeutic capacity of drugs by allowing them to escape lysosomal degradation is a long-term challenge for nanodrug delivery. Japanese encephalitis virus (JEV) has evolved the ability to escape the endosomal region to avoid degradation of internal genetic material by lysosomes and further induce upregulation of cellular autophagy for the purpose of their mass reproduction. In this work, to exploit the lysosome escape and autophagy-inducing properties of JEV for cancer therapy, we constructed a virus-mimicking nanodrug consisting of anti-PDL1 antibody-decorated JEV-mimicking virosome encapsulated with a clinically available autophagy inhibitor, hydroxychloroquine (HCQ). Our study indicated that the nanodrug can upregulate the autophagy level and inhibit the autophagic flux, thereby inducing the apoptosis of tumor cells, and further activating the immune response, which can greatly improve the antitumor and tumor metastasis suppression effects and provide a potential therapeutic strategy for tumor treatment.

Soluble expression and purification of human ß-defensin DEFB136 in Escherichia coli and identification of its bioactivity.

Human ß-defensins are an important family of innate host defense peptides with pleiotropic activities. Human ß-defensin 36 (DEFB136) is a novel member of the ß-defensin family which have not been characterized so far. In the present research, the DEFB136 peptide was expressed successfully and purified using the IMPACT-TWIN 1 expression system. The purified DEFB136 peptide was identified by MALDI-TOF mass spectrometry and circular dichroism spectroscopy. While the recombinant DEFB136 peptide exhibited a broad spectrum of antimicrobial activity against E. coli, Staphylococcus aureus and Candida albicans strains, but had low cytotoxicity to human erythrocytes. In addition, the result of the octet assay showed that the DEFB136 had a high lipopolysaccharide (LPS)-binding affinity, suggesting the DEFB136 may be involved in immunoregulation through its LPS neutralization. These results may help lay the groundwork to understand better the complex interaction between innate host defense and the diversity of the defensin family.

IL20RA signaling enhances stemness and promotes the formation of an immunosuppressive microenvironment in breast cancer.

Rationale: Tumor microenvironment interacts with tumor cells to regulate their stemness properties through various cytokines and cytokine receptors. Previous studies revealed the possible role of interleukin 20 receptor subunit alpha (IL20RA) signaling in the progression of several types of tumors. However, its regulatory effects on the stemness and the microenvironment of breast cancer need to be studied. Methods: Immunohistochemical staining and western blot analysis were used to evaluate the association between IL20RA and SOX2 in breast tumors and noncancerous tissues. Enzyme-linked immunosorbent assay and TCGA dataset analysis were performed to determine the function of IL20RA signaling in breast cancer progression. Gain- and loss-of-function methods were performed to examine the effects of IL20RA on the stemness of breast cancer cells. The stemness features were analyzed by detecting the expression of core stemness genes, side population (SP), sphere formation ability, and aldehyde dehydrogenase (ALDH) activity. Flow cytometric analysis was applied to detect the changes of tumor-infiltration lymphocytes in tumor tissues in mice. Based on the relevant molecular mechanisms elucidated in this study, a novel IL20RA-targeted liposomal nanoparticle encapsulating the signal transducer and activator of transcription 3 (STAT3) inhibitor stattic (NP-Stattic-IL20RA) was synthesized. These NPs were combined with anti-programmed death ligand 1 (PD-L1) antibody and chemotherapy to inhibit the development of breast tumors in mice. Results: IL20RA is highly expressed in human breast cancers and is positively associated with the SOX2 expression. IL20RA increases the SP and ALDHbr proportions of breast cancer cells, enhances the sphere formation ability, and promotes the expression of core stemness genes, such as Sox2 and Oct4, as well as increases chemoresistance of breast cancer cells. IL20RA promotes the tumor-initiating ability and lung metastasis of breast cancer cells in vivo. In addition, IL20RA activates the Janus kinase 1 (JAK1)-STAT3-SOX2 signaling pathway, leading to increased expression of PD-L1 and reduced recruitment of anti-cancer lymphocytes, including CD8+ T cells and natural killer cells. Meanwhile, IL20RA signaling enhances the proportion of myeloid-derived suppressor cells. Combined with anti-PD-L1 antibody and NPs-Stattic-IL20RA, the chemotherapeutic efficacy was increased in breast cancer mouse models in vivo. Conclusion: Collectively, our results reveal that the IL20RA pathway is a novel signaling pathway involved in promoting the stemness features of breast cancer along with the formation of a tumor-favorable immune microenvironment. Targeting the IL20RAhi population with STAT3 signaling inhibition combined with anti-PD-L1 antibody can increase the therapeutic efficacy of chemotherapeutic agents for breast cancer. This study thus introduces a promising novel strategy for breast cancer therapy.

Microbial communities and soil chemical features associated with commercial production of the medicinal mushroom Ganoderma lingzhi in soil.

Crop production, including mushroom farming, may cause significant changes to the underlying substrates which in turn, can influence crop quality and quantity during subsequent years. Here in this study, we analyzed the production of the medicinal mushroom Ganoderma lingzhi and the associated soil microbial communities and soil chemical features over 24 months from April 2015 to April 2017. This Basidiomycete mushroom, known as Lingzhi in China, is commonly found on dead trees and wood logs in temperate and subtropical forests. Its economic and medicinal importance have propelled the development of a diversity of cultivation methods. The dominant method uses wood logs as the main substrate, which after colonization by Lingzhi mycelia, are buried in the soil to induce fruiting. The soil microbial communities over the 24 months were analyzed using the Illumina HiSeq platform targeting a portion of the bacterial 16S rRNA gene and the fungal internal transcribed spacer 1 (ITS1). Overall, a significant reduction of Lingzhi yield was observed over our experimentation period. Interestingly, temporal changes in soil microbial compositions were detected during the 24 months, with the fungal community showing more changes than that of bacteria in terms of both species richness and the relative abundance of several dominant species after each fruiting. The soil chemical features also showed significant changes, with decreasing soil nitrogen and phosphorus concentrations and increasing soil pH and iron content after each fruiting. We discuss the implications of our results in sustainable Lingzhi production in soil.

Preparation and evaluation of dummy-template molecularly imprinted polymer as a potential sorbent for solid phase extraction of imidazole fungicides from river water.

Dummy molecularly imprinted polymer (DMIP) for imidazole fungicides was prepared for the first time using alpha-(2,4-Dichlorophenyl)-1H-imidazole-1-ethanol (DCE) as the fragment template. The imprinting selectivity of DCE-DMIP was evaluated for climbazole (CBZ), clotrimazole (CMZ) and miconazole (MNZ) by liquid chromatography, imprinting factors of 10.9, 10.8 and >10.7 were achieved, respectively. Heterogeneous binding sites were found in the DCE-DMIP, the corresponding saturation capacity and dissociation constant for the high affinity binding sites were 13.05 µmol g-1 and 0.4701 mmol L-1. High efficient method based on dummy molecularly imprinted solid phase extraction (DMISPE) coupled with HPLC was established for the selective enrichment of CBZ, CMZ and MNZ in river water using DCE-DMIP as sorbent. DMISPE conditions including sample loading pH/volume, selective washing and elution solvents were carefully optimized. The developed method showed good recoveries (84.2-95.0%) and precision (RSDs 1.7-5.0%, n = 5) for samples spiked at two different concentration levels (0.5 and 2.5 µg L-1). The detection limits were ranged from 0.023 to 0.031 µg L-1. The results demonstrated good potential of this method for sample pretreatment of azole fungicides in environmental water samples.