The deficiency of effective biomarker for the toxic effects of water pollutants greatly limits the application of biological monitoring. This study aimed to investigate the possibility of circulating exosomes of indigenous fish acting as biomarker for the ecotoxicity effect of water environment. The Helong Reservoir in Guangzhou, China, was chosen as the investigating field, of which the water quality belongs to Class V (2013) (GB 3838-2002, China). The clean drinking water source of the upper reaches of the Liuxihe Reservoir was selected as the control. Indigenous fishes including Oreochromis niloticus (Nile tilapia), Labeo rohita (Rohu), Carassius auratus (Crucian carp) were sampled during the period from July 2020 to April 2021. Circulating exosomes of fish samples were isolated by using ultracentrifugation, characterized with transmission electron microscopy (TEM) and quantified by using bicinchoninic acid (BCA) assay. Oxidative stress, DNA and chromosome damage in liver, kidney, brain, gill and blood of fish samples were measured. The results showed that there were significant differences in superoxide dismutase (SOD) activity, glutathione (GSH) and malondialdehyde (MDA) contents, DNA and chromosome damage in fish samples between the Helong Reservoir and the control. Interestingly, there were also significant differences in circulating exosome levels of fish samples between them. Our data suggested that circulating exosome level of indigenous fish may be a novel biomarker for the ecotoxicity effects of water environment.

为探讨黄龙带水库浮游生物现状及水质情况,于2021年2—5月对黄龙带水库进行环境流行病学调查采样,分析其浮游生物的种类组成和丰度;通过Shannon-Wiener多样性指数和Pielou均匀度指数对水质进行综合评价.结果表明:本次调查共采集到黄龙带水库浮游植物6门30种,其优势藻类为绿藻门;浮游动物13属15种,以轮虫门为主.浮游植物和浮游动物丰度分别为10.00×105 ind./L和413 ind./L.黄龙带水库浮游生物Shannon-Wiener多样性指数大于3;浮游植物和浮游动物Pielou均匀度指数分别为0.67和0.94.黄龙带水库浮游生物多样性较高,水质综合评价结果为清洁贫营养型.

了解广州市典型水库水环境因子与浮游生物生态学现状及其水质情况,为水质安全的预防和控制工作提供基础资料.于2021年2月至5月,对该市典型水库进行了现场环境流行病学现况调查.根据水库水环境的历史资料,有针对性地对8种环境因子进行了检测;分析水环境中浮游动物及浮游植物的构成及丰度;运用Shannon-Weaver指数法分析水环境中浮游生物的多样性;运用Pielou指数法分析水环境中浮游生物的均匀度;基于浮游生物的生态学现状,对水环境质量进行了初步评价.参照《地表水环境质量标准》(GB 3838—2002),8种环境质量指标符合Ⅱ类水质限值.本次调查共采集到浮游植物6门40种,丰度为26.67×105 ind./L,优势藻类为绿藻(37.5％)和蓝藻(30％);浮游动物共采集到17属25种,丰度为488 ind./L,优势种类为轮虫(64％);浮游植物Shannon-Weaver多样性指数为1.35;浮游动物Shannon-Weaver多样性指数为1.22;浮游植物Pielou均匀度指数为0.25;浮游动物Pielou均匀度指数为0.26.虽然该水库理化指标符合Ⅱ类水质限值,但浮游生物多样性指数及均匀度指数较低.本次调查暴露了水质理化指标的局限性,理化指标无法全面反映水质的生态健康状况.水质理化监测与生物监测的联合运用,在水环境质量的全面和客观评价中具有重要意义.

目的 探讨某市典型水库水质的生态毒理学效应,为地方水质安全防护措施的合理实施提供基础资料.方法 自2020年7月～2021年4月,通过环境流行病学现场调查,采集在某市典型水库库区及清洁对照组水源生长的野生鲫鱼、泰国鲮鱼以及尼罗罗非鱼样本;运用微核实验分析鱼血细胞的染色体损伤效应;运用单细胞凝胶电泳技术(single cell gel electrophoresis,SCGE)分析鱼血细胞及肝细胞的DNA损伤效应;采用试剂盒法检测鱼肝组织超氧化物歧化酶(SOD)活性、谷胱甘肽(GSH)和丙二醛(MDA)含量;运用鱼卵黄蛋白原(vitellogenin,VTG)ELISA试剂盒法检测鱼血浆VTG水平,分析水质的环境雌激素效应.结果 某市典型水库库区3种鱼类血细胞彗星尾部DNA含量及血细胞微核形成率明显高于清洁对照组鱼类(P＜0.05);典型水库库区3种鱼类肝组织SOD活性明显低于对照组(P＜0.05),GSH及MDA含量明显高于对照组(P＜0.05);典型水库库区尼罗罗非鱼血浆VTG水平明显高于对照组(P＜0.05),而鲫鱼、泰国鲮鱼血浆VTG水平差异无统计学意义(P＞0.05).结论 某市典型水库水质对库区野生鱼类可能具有一定的生态毒性效应.

探讨广州市增塘水库浮游生物种群特征及水质现状,为水质安全监控提供基础资料.于2021年3—7月,运用环境流行病学现场调查采样方法,采集增塘水库浮游植物及浮游动物样本,分析其种群构成及丰度;采用Shannon-Weaver指数法分析水库浮游生物的多样性;采用Pielou指数法分析水库浮游生物的均匀度;基于上述指数对水库的水环境质量做出初步评价.本次调查共采集到浮游植物35种,隶属于5门27属.其中优势藻类为绿藻13种(37.15％),其次为蓝藻10种(28.57％);浮游植物丰度为29.00×105 ind./L,其中硅藻门的丰度最大,为13.05×105 ind./L.浮游动物共计14属19种,其中轮虫12种(63.16％),为优势种群,其次为桡足类5种(26.31％);浮游动物丰度为967 ind./L,其中轮虫丰度最大,为860 ind./L.浮游植物Shannon-Weaver H'为3.24,对应水质为清洁;浮游动物Shannon-Weaver H'为2.24,对应水质为轻度污染;浮游植物Pielou J'为0.63,对应水质为轻度污染;浮游动物Pielou J'值为0.53,对应水质为轻度污染.本次环境流行病学现场调查结果提示,广州市增塘水库水质目前处于轻度污染状态.

The present study was conducted to assess the genotoxic potential of water from the Helong Reservoir, which was designated as a strategic drinking water source by the Guangdong Provincial Government of China in October 2016. Four kinds of common indigenous fish samples (Labeo rohita, Cirrhinus molitorella, red tilapia, and Oreochromis niloticus) were collected at 6 sampling sites during the period from July to November 2020. Fish from the clean drinking water source of the upper reaches of the Liuxihe Reservoir in Guangzhou were collected as the control. Both the alkaline single cell gel electrophoresis assay and the micronucleus test were used to detect DNA damage and the micronucleus rate in erythrocytes of fish samples, respectively. The results indicated that there was a significant increase in comet tail length, Olive tail moment, and micronucleus rates of all fish samples compared with those of the control (p < 0.05). The order of sensitivity to DNA damage and micronucleus formation was Labeo rohita > Cirrhinus molitorella > red tilapia > Oreochromis niloticus. The results of the 2 kinds of experiments were in perfect agreement with each other. We conclude that there are obvious genotoxic effects from the water in the Helong Reservoir. As a strategic drinking water source, the safety of the Reservoir water quality should be considered. The local government should put the restoration of the Helong Reservoir water quality on the agenda as soon as possible. Environ Toxicol Chem 2021;40:1919-1927. © 2021 SETAC.

Objective Although benzene is a confirmed environmental carcinogen, the mechanism of its carcinogenicity remains largely unclear. The suggested oncogene, miR-221, is elevated and plays important roles in various tumors, but its role in benzene-induced carcinogenesis remains unknown. Methods In the present study, we constructed hydroquinone (HQ, a representative metabolite of benzene with biological activity)-transformed malignant cell line (16HBE-t) and analyzed the level of miR-221 in it with qRT-PCR. Exosomes from 16HBE-t cells incubated with or without an miR-221 inhibitor were isolated by ultracentrifugation, characterized by transmission electron microscopy and laser scanning confocal microscope, and then transfected into 16HBE cells. The effects of exosomal miR-221 on apoptosis induced by HQ in recipient cells were determined using flow cytometry. Results The amount of miR-221 in 16HBE-t was significantly increased compared with controls. When recipient cells ingested exosomes derived from 16HBE-t, miR-221 was increased, and apoptosis induced by HQ was inhibited. Blocking miR-221 in 16HBE-t using an inhibitor did not significantly alter miR-221 or apoptosis in recipient cells. Conclusion Exosomal miR-221 secreted by 16HBE-t inhibits apoptosis induced by HQ in normal recipient cells.

A creative combination of chitosan with polyacrylic acid (PAA) improves the acidity resistance of chitosan and increases its potential in the field of adsorption. In order to facilitate recovery, magnetic nanoparticles were incorporated in CS-PAA to obtain a magnetic-CS-PAA (MCS-PAA) nanocomposite. The physical and chemical characteristics of the composite adsorbent MCS-PAA were determined by SEM, TEM, FTIR, EDX, XRD, and XPS. This environmental-friendly, magnetic, composite adsorbent showed significantly better adsorption performance than those of the individual adsorbents alone. The maximal adsorption capacity was 204.89 mg/g according to the Langmuir isotherm model, when the concentration of Pb(II) was 100 mg/L at the equilibrium time of 70 min. The main adsorption mechanism was the complexation between the carboxyl, amino, and hydroxyl groups in MCS-PAA and Pb(II). Further, introduction of PAA also improved the acid resistance of CS. The new adsorbent MCS-PAA is thus expected to facilitate a wider range of applications for chitosan in the adsorption of Pb(II). (C) 2019 Elsevier B.V. All rights reserved.

A novel ethylenediaminetetraacetic acid (EDTA)-functionalized magnetic chitosan oligosaccharide and carboxymethyl cellulose (Fe3O4@CMCCOS-EDTA) nanocomposite adsorbent was successfully fabricated for Pb(II) adsorption. The adsorbent was characterized by Fourier transform infrared, and X-ray photoelectron spectroscopy was used to confirm successful EDTA modification and Pb(II) adsorption. Scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, and thermogravimetric analysis were used to study the morphology and properties of magnetic particles. EDTA modification considerably improved the capacity of the adsorbent. The batch adsorption experiment results indicated that the pseudo-second-order (PSO) model and the Langmuir isotherm model reliably described the adsorption behavior. The maximum adsorption capacity (qm) for monolayer chemical adsorption was calculated to be 432.34 mg/g at the pH of 5 and temperature of 308 K. Notably, Fe3O4@CMCCOS-EDTA exhibited a high Pb(II) removal rate of ~100% using an initial metal ion solution of 100 mg/L and 200 mg/L.

Accumulating evidence reveals that exosome plays an important role in cell-to-cell communication in both physiological and pathological processes by transferring bioactive molecules. However, the role of exosomal secretion in the adaption of its source cells to the stimuli of environmental chemicals remains elusive. In this study, we revealed that the exposure of hydroquinone (HQ; the main bioactive metabolite of benzene) to human bronchial epithelial cells (16HBE) resulted in decreased ability of cell proliferation and migration, and simultaneously DNA damage and micronuclei formation. Interestingly, when exosomal secretion of HQ treated 16HBE cells was inhibited with the inhibitor GW4869, cellular proliferation and migration were further significantly reduced; concurrently, their DNA damage and micronuclei formation were both further significantly aggravated. Herein, we conclude that exosomal secretion of 16HBE cells may be an important self-protective function against the toxic effects induced by HQ.

The gene encoding the tumor suppressor, phosphatase and tensin homolog (PTEN), located on chromosome 10, is frequently expressed at low levels in various tumors, resulting in the stimulation of cell proliferation and migration. However, the role of exosomal PTEN in cell-cell communication during the progress of benzene-induced carcinogenesis remains unclear. The goal of this study was to explore whether exosomes derived from normal human bronchial epithelial cells (16HBE) could transmit PTEN to hydroquinone-transformed malignant recipient cells (16HBE-t) and its possible effects on cell proliferation and migration. Consistent with PTEN expression being down-regulated in transformed cells, we found that its expression was significantly decreased in 16HBE-t relative to 16HBE cells and that purified exosomes secreted by 16HBE, up-regulated PTEN levels in recipient 16HBE-t cells. Thus, down-regulating their proliferation and migration. Further, when exosomes derived from 16HBE cells that had been treated with the PTEN inhibitor SF1670, were incubated with recipient 16HBE-t cells, they exhibited decreased PTEN levels, with a corresponding increase in their proliferation and migration. In conclusion, our study demonstrates that exosomes derived from 16HBE cells can down-regulate proliferation and migration of recipient 16HBE-t cells via transferring PTEN.

miR-221, an oncogenic microRNA, can promote cell proliferation and is highly expressed in various types of tumors. However, the role of exosomal miR-221 in benzene-caused carcinogenesis remains elusive. Our study was designed to investigate whether exosomes secreted by the hydroquinone (HQ; an active metabolite of benzene)-transformed malignant cells can transmit miR-221 to normal recipient cells and its possible effects on cell viability. Our investigation revealed that expression levels of miR-221 were significantly increased in HQ-transformed malignant cells relative to normal controls. Furthermore, exposure of control cells to exosomes that were derived from HQ-transformed malignant cells increased miR-221 levels and promoted their proliferation. Analyses of the biological potency of exosomes derived from HQ-transformed malignant cells in which miR-221 levels were decreased using an inhibitor, showed that both miR-221 levels and proliferation of recipient cells were decreased, but still were higher than those of normal 16HBE cells. Our study indicates that exosomal miR-221 derived from HQ-transformed malignant human bronchial epithelial cells is involved in the proliferation of recipient cells.

目的 探讨苯的活性代谢物氢醌(HQ)对16HBE细胞的毒性作用,对其miR-221及抑癌基因PTEN mRNA表达的影响.方法 运用常规细胞传代培养方法培养16HBE细胞至第25代,每代细胞均以20 μmol/L的HQ进行染毒;光学显微镜下观察每代细胞的细胞形态学特征,CCK-8法绘制细胞生长曲线;qRT-PCR法分析每代细胞miR-221及其靶分子PTEN mRNA的表达.结果 HQ处理对各代活细胞的形态学影响无明显差异,可见部分活细胞发生皱缩,死亡细胞悬浮于培养基中;各代细胞的生长曲线无明显差异;miR-221表达在第25代时明显增强;PTEN mRNA在第5代表达增强,随后逐代降低.结论 HQ可诱导miR-221表达增强,抑癌基因PTEN mRNA表达先增强后抑制.

Temozolomide (TMZ), a therapeutic DNA alkylator that can cause lethal DNA damage in cancer cells, is widely used for the standard chemotherapy against glioblastoma. However, long-term treatment with TMZ often causes drug resistance and poor prognosis, the mechanism of which remains largely unclear. This study aimed to investigate the possible role of miR-222/GAS5 axis on DNA damage and cytotoxic effects induced by TMZ in glioblastoma cells (T98G). Data suggest that the DNA comet tail length of T98G is positively correlated with the levels of miR-222 (R-2 = 0.9808, P < 0.05), and negatively correlated with the levels of GAS5 (R-2 = 0.8903, P < 0.05). The optical density value of T98G is negatively correlated with the levels of miR-222 (R-2 = 0.7848, P < 0.05), and positively correlated with the levels of GAS5 (R-2 = 0.6886, P < 0.05). Furthermore, comet tail length and optical density value are negatively and positively correlated with the levels of O-6-methylguanine-DNA methyltransferase, respectively (R-2 = 0.8462, P R-2 = 0.7018, P < 0.05). In conclusion, miR-222/GAS5 is involved in DNA damage and cytotoxic effects induced by TMZ, which means that miR-222/GAS5 may have great potential of being used as a biomarker for screening of chemotherapeutic alkylators.