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1.
Ecotoxicol Environ Saf ; 208: 111699, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396030

RESUMO

Extensive industrial activities have led to an increase of the content of chromium in the environment, which causes serious pollution to the surrounding water, soil and atmosphere. The enrichment of chromium in the environment through the food chain ultimately affects human health. Therefore, the remediation of chromium pollution is crucial to development of human society. A lot of scholars have paid attention to bioremediation technology owing to its environmentally friendly and low-cost. Previous reviews mostly involved pure culture of microorganisms and rarely discussed the optimization of bioreduction conditions. To make up for these shortcomings, we not only introduced in detail the conditions that affect microbial reduction but also innovatively introduced consortium which may be the cornerstone for future treatment of complex field environments. The aim of this study is to summary chromium toxicity, factors affecting microbial remediation, and methods for enhancing bioremediation. However, the actual application of bioremediation technology is still facing a major challenge. This study also put forward the current research problems and proposed future research directions, providing theoretical guidance and scientific basis for the application of bioremediation technology.


Assuntos
Biodegradação Ambiental , Cromo/isolamento & purificação , Poluentes Ambientais/isolamento & purificação , Cromo/metabolismo , Cromo/toxicidade , Poluentes Ambientais/metabolismo , Poluentes Ambientais/toxicidade , Humanos , Consórcios Microbianos/fisiologia
2.
Ecotoxicol Environ Saf ; 208: 111758, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396081

RESUMO

The cultivation of leafy vegetables on metal contaminated soil embodies a serious threat to yield and quality. In the present study, the potential role of exogenous jasmonic acid (JA; 0, 5, 10, and 20 µM) on mitigating chromium toxicity (Cr; 0, 150, and 300 µM) was investigated in choysum (Brassica parachinensis L.). With exposure to increasing Cr stress levels, a dose-dependent decline in growth, photosynthesis, and physio-biochemical attributes of choysum plants was observed. An increase in Cr levels also resulted in oxidative stress closely associated with higher lipoxygenase activity (LOX), hydrogen peroxide (H2O2) generation, lipid peroxidation (MDA), and methylglyoxal (MG) levels. Exogenous application of JA alleviated the Cr-induced phytotoxic effects on photosynthetic pigments, gas exchange parameters, and restored growth of choysum plants. While exposed to Cr stress, JA supplementation induced plant defense system via enhanced regulation of antioxidant enzymes, ascorbate and glutathione pool, and the glyoxalase system enzymes. The coordinated regulation of antioxidant and glyoxalase systems expressively suppressed the oxidative and carbonyl stress at both Cr stress levels. More importantly, JA restored the mineral nutrient contents, restricted Cr uptake, and accumulation in roots and shoots of choysum plants when compared to the only Cr-stressed plants. Overall, the application of JA2 treatment (10 µM JA) was more effective and counteracted the detrimental effects of 150 µM Cr stress by restoring the growth and physio-biochemical attributes to the level of control plants, while partially mitigated the detrimental effects of 300 µM Cr stress. Hence, JA application might be considered as an effective approach for minimizing Cr uptake and its detrimental effects in choysum plants grown on contaminated soils.


Assuntos
Antioxidantes/farmacologia , Brassica/fisiologia , Cromo/toxicidade , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Brassica/efeitos dos fármacos , Brassica/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo
3.
Ecotoxicol Environ Saf ; 208: 111685, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396017

RESUMO

The wastewater utilization for irrigation purposes is common practice in peri-urban areas located in vicinity of developed cities. This water contains elements like chromium (Cr), nickel (Ni), cadmium (Cd) and nitrate (NO3-N) that poses health risk when exposed to human. In this study effect of wastewater irrigation from Chakara wastewater plant, Faisalabad on growth of wheat and health risks was assessed. Pot experiment was conducted at Institute of Soil and Environmental, University of Agriculture, Faisalabad using different concentration of wastewater as treatment 100% tap water, 25% wastewater + 75% tap water, 50% wastewater + 50% tap water, 75% wastewater + 25% tap water, 100% wastewater. The results indicated that the wastewater irrigation negatively effects the plant growth and physiological parameters. The minimum plant height, grain weight, spike length, osmotic potential and SPAD values were recorded 50.33 cm, 1.47 g plant-1, 7.00 cm, 423 and 38.91 respectively in 100% wastewater irrigation. The risk quotient (RQ TEs) for each toxic element and cumulative risk index (RI TEs) values were calculated. The cadmium risk quotient (Cd RQ) for adults was on margin and value was >1 for in 75% wastewater + 25% tap water and 100% wastewater irrigation, while the RQ for Ni and Cr was <1. Maximum RI TEs values calculated in 100% wastewater irrigation 0.424 and 0.294 for children and adults respectively. Hence it was concluded that wastewater irrigation significantly increased the accumulation rate of metals and nitrate in wheat and cause potential health risks for children and adults.


Assuntos
Irrigação Agrícola/métodos , Bioacumulação/efeitos dos fármacos , Metais Pesados/toxicidade , Nitratos/toxicidade , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Águas Residuárias/química , Adulto , Cádmio/análise , Cádmio/toxicidade , Criança , Cromo/análise , Cromo/toxicidade , Cidades , Grão Comestível/química , Humanos , Metais Pesados/análise , Modelos Teóricos , Níquel/análise , Níquel/toxicidade , Nitratos/análise , Paquistão , Medição de Risco , Solo/química , Poluentes do Solo/análise , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Águas Residuárias/análise
4.
Ecotoxicol Environ Saf ; 211: 111908, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33440265

RESUMO

Hexavalent chromium [Cr(VI)] is a common heavy metal pollutant that can cause a number of human disease, including inflammation and cancer. Senescent cells can secrete a variety of molecules known as senescence-associated secretory phenotype (SASP). Our previous studies have confirmed that Cr(VI) can induce premature senescence in L02 hepatocytes, but the composition and the function of the related SASP are still unknown. In order to understand the components of SASP secreted by senescent L02 hepatocytes under the action of Cr(VI), we applied LC-MS/MS-based label-free protein quantification. We found that three SASP components including Coactosin-like protein 1 (COTL1), Alpha-enolase (ENO1), and Peroxiredoxin 2 (PRDX2) were up-regulated, which were confirmed by western blotting and qRT-PCR. Evidence suggested that SASP may promote the development of tumor through chronic inflammatory response, therefore we identified and analyzed the potential biological functions and signaling pathways of these three SASP components using GO and KEGG methods. The interaction between SASP components was analyzed by STRING, and verified by Co-IP. We also found that ENO1 and PRDX2, which have direct interaction, can inhibit the growth and proliferation of wildtype hepatocytes and premature senescent hepatocytes, but can promote the proliferation and behavioral changes of liver tumor cells. The present study provides valuable clues for elucidation of the carcinogenic mechanism of Cr(VI), especially for further prevention and targeted treatment of Cr(VI)-related cancer.


Assuntos
Senescência Celular , Cromo/toxicidade , Linhagem Celular , Cromatografia Líquida , Hepatócitos/metabolismo , Humanos , Proteínas dos Microfilamentos/metabolismo , Fenótipo , Transdução de Sinais , Espectrometria de Massas em Tandem , Regulação para Cima
5.
Environ Pollut ; 272: 116407, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33433342

RESUMO

The wide range of industrial applications of chromium (Cr) has led to an increasing risk of water contamination by Cr(Ⅵ). However, efficient methods to remove or decrease the toxicity of Cr(Ⅵ) in situ are lacking. The main aim of this study was to investigate the mechanisms by which selenite alleviates chromium(Ⅵ)-induced toxicity in Chlamydomonas reinhardtii. Our results showed that K2Cr2O7 had toxic effects on both the structure and physiology of C. reinhardtii in a dose-dependent manner. Adding selenite significantly alleviated chromium accumulation and toxicity in cells. RNA-seq data showed that the expression level of selenoproteins such as SELENOH was significantly increased. Both SELENOH-amiRNA knockdown mutants and selenoh insertional mutant produced more reactive oxygen species (ROS) and grew slower than the wild type, suggesting that SELENOH can reduce chromium toxicity by decreasing the levels of ROS produced by Cr(Ⅵ). We also demonstrated that selenite can reduce the absorption of Cr(Ⅵ) by cells but does not affect the process of Cr(Ⅵ) adsorption and efflux. This information on the molecular mechanism by which selenite alleviates Cr(Ⅵ) toxicity can be used to increase the bioremediation capacity of algae and reduce the human health risks associated with Cr(Ⅵ) toxicity.


Assuntos
Chlamydomonas reinhardtii , Selênio , Chlamydomonas reinhardtii/genética , Cromo/toxicidade , Humanos , Ácido Selenioso/toxicidade , Selênio/toxicidade
6.
Plant Physiol Biochem ; 159: 285-300, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33418188

RESUMO

Application of the growth regulator salicylic acid (SA) and the polyamine spermidine (Spd) can be used to manage various plant abiotic stresses. We aimed to evaluate the sole and combined effects of SA and Spd on maize (Zea mays) under individual and combined drought and chromium (Cr) stress. Drought, Cr, and drought + Cr treatments caused oxidative stress by inducing higher production of reactive oxygen species (H2O2, O2-), enhanced malondialdehyde content and increased relative membrane permeability. Increased oxidative stress and higher Cr uptake in the host plant reduced the content of carotenoids, other photosynthetic pigments and protein, and changed carbohydrate metabolism. Combined drought + Cr stress was more damaging for the growth of maize plants than the individual stresses. Exogenous treatments of SA and Spd alleviated the adverse effects of drought and Cr toxicity, reflected by accumulations of osmolytes, antioxidants and endogenous polyamines. Single applications of Spd (0.1 mM) increased plant height, shoot fresh weight, leaf area, above-ground dry matter accumulation and polyamine content under drought, Cr, and drought + Cr stress conditions. However, the combined treatment SA + Spd (0.25 mM + 0.05 mM) was more effective in increasing protein and water contents, photosynthetic pigments, and carotenoids. The same treatment increased Cr tolerance in the maize plants by decreasing uptake of this heavy metal from root to shoot. The SA + Spd treatment also decreased oxidative stress by promoting antioxidant enzyme activities, and enhanced levels of proline, soluble sugars, and carbohydrate contents under individual and combined stress conditions. Results indicate that the combined half-dose application of SA + Spd may be utilized to boost the tolerance in maize under individual as well as combined drought and Cr stress conditions.


Assuntos
Cromo , Secas , Espermidina , Estresse Fisiológico , Zea mays , Antioxidantes/metabolismo , Cromo/toxicidade , Peróxido de Hidrogênio/metabolismo , Ácido Salicílico/farmacologia , Espermidina/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Zea mays/efeitos dos fármacos
7.
J Environ Manage ; 280: 111809, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360556

RESUMO

Despite the importance of chromium (Cr) in most anthropogenic activities, the subsequent environmental adulteration is now a source of major concern. Cr occurs in numerous oxidation states, with the furthermost stable and frequently occur states being Cr(0), Cr(III) and Cr(VI). Cr(0) and Cr(III) are vital trace elements while Cr(VI) is dispensable and noxious to living organisms. Predominantly in plants, Cr at low concentrations of about 0.05-1 mg/L assist to boost growth as well as increase productivity. However, accumulation of Cr could represent a potential threat to living organisms. Cr absorption, displacement and accretion depend on its speciation, which also determines its toxicity which is often diverse. Indications of its toxicity include; reduction of seed germination, retardation of growth, reduction of yield, inhibition of enzymatic activities, weakening of photosynthesis, nutrient, oxidative disparities and genetic mutation in plants as well as several injurious diseases in animals and humans. In this study, we have presented a comprehensive review as well as an informative account of the influence of Cr on the environment drawn from researches carried out over the years following an analytical approach. Uniquely, this work presents a review of the effects and remediation of Cr from soil and wastewater drawn from several evidence and meta-data-based articles and other publications. Accordingly, the write-up is intended to appeal to the consciousness of the general public that the significance of Cr notwithstanding, its environmental toxicity should not be taken for granted.


Assuntos
Cromo , Poluentes do Solo , Animais , Cromo/análise , Cromo/toxicidade , Humanos , Solo , Poluentes do Solo/toxicidade , Águas Residuárias
8.
Chemosphere ; 262: 128422, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182085

RESUMO

This study evaluated the toxicity of Cr(VI) to microalgae Chlorella vulgaris, and its removal by continuous microalgae cultivation in membrane photobioreactor (MPBR). Batch cultivation in photobioreactors showed that low concentration of Cr(VI) (0.5 and 1.0 mg L-1) stimulated the growth of C. vulgaris, while 2.0 and 5.0 mg L-1 Cr(VI) in the wastewater significantly inhibited the growth of C. vulgaris. Superoxide dismutase and catalase activities that represented cellular antioxidant capacity significantly increased at 0.5 and 1.0 mg L-1 Cr(VI), and then gradually decreased with the continuous increase of Cr(VI) concentration. The content of malondialdehyde, which represents the degree of cellular oxidative damage, increased with the increase of Cr(VI) concentration and reached the peak value at 2.0 mg L-1 Cr(VI). C. vulgaris was then cultured in MPBR equipped with hollow-fiber ultrafiltration membrane module to achieve continuous removal of Cr from wastewater. With the in-situ solid-liquid separation function of the membrane module, solid retention time (SRT) and hydraulic retention time (HRT) of the reactor could be controlled separately. Experimental results showed that both SRT and HRT had significant effects on the algal biomass production and pollutants removal. During the continuous operation, MPBR achieved a maximum total Cr reduction of 50.0% at HRT of 3-day and SRT of 40-day, and a maximum volumetric removal rate of total Cr of 0.21 mg L-1 d-1 at HRT of 2-day and SRT of 40-day.


Assuntos
Chlorella vulgaris/fisiologia , Cromo/toxicidade , Fotobiorreatores , Eliminação de Resíduos Líquidos , Biomassa , Chlorella vulgaris/crescimento & desenvolvimento , Cromo/análise , Estudos Longitudinais , Membranas Artificiais , Microalgas/crescimento & desenvolvimento , Oxirredução , Águas Residuárias
9.
Ecotoxicol Environ Saf ; 209: 111784, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33316727

RESUMO

Cysteine (Cys) is incorporated into several compounds which are involved in detoxification of heavy metals. It is evident from recent studies that Cys is effective in alleviating the toxicity of heavy metals. Nevertheless, little is known about the Cys-mediated alleviation of chromium (Cr) toxicity. In our study, the impacts of exogenous Cys on Cr-stressed maize (Zea mays L.) were examined by using physiological and proteomic analyses. The results showed that Cr (100 µM) increased the accumulation of hydrogen peroxide, decreased cell viability, enhanced lipid peroxidation and consequently inhibited plant growth. The application of Cys (500 µM) attenuated the adverse effects of Cr on seedling growth. Cys supplementation to Cr treated plants decreased Cr accumulation in the shoots and increased Cr accumulation in roots. Cys treatment also modulated the activities of antioxidant enzymes and increased endogenous Cys content. Sixty proteins in root tissue were significantly affected by exogenous Cys under Cr stress using two-dimensional electrophoresis. Forty-six differentially expressed proteins were successfully identified by MALDI-TOF/TOF mass spectrometry. These differentially expressed proteins were involved in various biological pathways such as stress response (41.3%), energy and carbohydrate metabolism (21.7%), protein metabolism (6.5%), amino acid metabolism (6.5%), and others of unknown functions. The defense response-related proteins including glutathione peroxidase, glutathione S-transferases, pathogenesis-related proteins, glyoxalases and superoxide dismutase were differently regulated by Cys suggesting their roles in the Cys-mediated Cr tolerance.


Assuntos
Antioxidantes/farmacologia , Cromo/toxicidade , Cisteína/farmacologia , Poluentes do Solo/toxicidade , Zea mays/fisiologia , Antioxidantes/metabolismo , Cromo/metabolismo , Cisteína/metabolismo , Glutationa Peroxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Lactoilglutationa Liase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteoma/efeitos dos fármacos , Proteômica , Plântula/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Zea mays/metabolismo
10.
Chemosphere ; 263: 128281, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297225

RESUMO

Hexavalent chromium (Cr(VI)) is a carcinogenic compound that can be removed from contaminated sites by the activity of metal-reducing bacteria. The model bacterium Geobacter sulfurreducens reduces Cr(VI) to less toxic Cr(III) and accumulates Cr ions intracellularly. However, this process is usually slow with small concentrations of Cr(VI) removed in a matter of days. Here, high-density G. sulfurreducens cultures were tested for the capacity to remove Cr(VI) readily. With an initial G. sulfurreducens density of 5.8 × 108 cells ml-1, 99.0 ± 0.8% of 100 mg l-1 Cr(VI) was removed after 20 min. With a higher starting Cr(VI) concentration of 200 mg l-1, G. sulfurreducens with a density of 11.4 × 108 cells ml-1 removed 99.0 ± 0.4% Cr(VI) after 2 h. Experiments performed with cell-free spent medium indicate that extracellular proteins are major contributors for the reduction of Cr(VI) to Cr(III). Furthermore, results show that most Cr(III) ions ultimately end up inside the bacterial cells where they are less susceptible to re-oxidation. The fast Cr(VI) removal rates observed with high-density G. sulfurreducens demonstrate the potential of this bacterium for bioremediation applications such as the cleaning of industrial wastewaters.


Assuntos
Cromo , Geobacter , Biodegradação Ambiental , Cromo/toxicidade , Oxirredução
11.
Chemosphere ; 262: 127806, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32750591

RESUMO

In the view of green and efficient removal of chromium pollution, uniform fiber ball loaded with Fe(OH)3 (UFB-Fe(OH)3), was firstly synthesized and successfully used in the photoreduction of Cr(VI) by oxalate acid (Ox). The Cr(VI) removal in UFB-Fe(OH)3+Ox + UV system was examined by the effect of concentration of Ox, initial Cr(VI) concentration, dosage of UFB-Fe(OH)3 and the reusability of UFB-Fe(OH)3. By studying the impact of the initial pH in the solution, the relationship between the change in pH during the reaction and the removal efficiency of Cr(VI), the effect of coexisting ion (NO3-), and the free radicals quenching tests, the Cr(VI) removal mechanism in UFB-Fe(OH)3+Ox + UV system was further deduced. The results showed that UFB-Fe(OH)3 could greatly enhance the photoreduction of Cr(VI) by Ox, 1.5 mM Cr(VI) was completely removed in 6 min by UFB-Fe(OH)3+Ox + UV system. UFB-Fe(OH)3 had the feasibility of multiple use, it still exhibited the excellent enhancement in Cr(VI) removal by Ox after six cycles of use. The Cr(VI) photoreduction mechanism was consist of three part: i) Ox generate a part of CO2·- under the ultraviolet (UV) to reduce Cr(VI); ii) the Fe(III) dissolved by UFB-Fe(OH)3 formed FeOH2+ in the solution, and then generated very little Fe(II) under UV to remove Cr(VI); iii) the synergistic effect of UFB-Fe(OH)3 and Ox rapidly generated a large number of CO2·- and Fe(II) under UV excitation to reduce Cr(VI).


Assuntos
Cromo/química , Oxalatos/química , Poluentes Químicos da Água/química , Cromo/toxicidade , Ferro , Compostos Orgânicos , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Sci Total Environ ; 752: 141824, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32896789

RESUMO

Chromium (Cr) can coexist with other heavy metals in the blood of chronically chromate-exposed individuals. However, few studies have explored the health impacts of other hazardous metals after exposure to hexavalent chromium [Cr(VI)]. This study aimed to assess the modification effects of blood lead (Pb) on the genetic damage induced by Cr(VI). During 2010-2019, 1000 blood samples were collected from 455 workers exposed to chromate and 545 workers not exposed to chromate from the same factory with similar labor intensity. The levels of Cr and Pb were measured in whole blood samples. Micronucleus frequency (MNF) and urinary 8-hydroxydeoxyguanosine (8-OHdG) were measured to reflect different types of genetic damage. Multivariate linear regression analyses were performed to evaluate the associations between hazardous metals and the modification effects of Pb on genetic damage. The geometric mean levels of Cr and Pb in the exposure group were significantly higher than those in the control group [Cr: 6.42 (6.08- 6.79) vs. 1.29 (1.22- 1.36) µg/L; Pb: 38.82 (37.22- 40.50) vs. 34.47 (33.15- 35.85) µg/L]. The geometric means of urinary 8-OHdG and MNF in exposure group were 4.00 (3.64- 4.40) µg/g and 5.40 (4.89- 5.97) ‰, respectively, significantly higher than the 3.20 (2.94- 3.48) µg/g and 4.57 (4.15- 5.03) ‰, respectively, in control group. log2Cr was independently and positively associated with urinary 8-OHdG (ß-adjusted = 0.143, 95% CI: 0.082- 0.204) and MNF (ß-adjusted = 0.303, 95%CI: 0.020- 0.587). With the change in circulating Pb levels, the types of genetic damage induced by Cr(VI) were different. At low levels of circulating Pb (<30.80 µg/L), chromate mainly caused changes in 8-OHdG, while at high circulating Pb levels (≥44.88 µg/L), chromate induced alterations in MNF. The findings suggested that chromate exposure could cause multiple types of genetic damage, and circulating Pb might modify the association between circulating Cr and the form of genetic damage.


Assuntos
Cromatos , Exposição Ocupacional , Cromatos/toxicidade , Cromo/toxicidade , Estudos Epidemiológicos , Humanos , Chumbo/toxicidade , Exposição Ocupacional/análise
13.
Mar Pollut Bull ; 160: 111673, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33181946

RESUMO

Heavy metal pollution arising from agricultural and industrial activities poses a significant threat to the aquatic environment, especially the increasing levels of chromium (Cr) that is exacerbating marine pollution. Given the economic importance of the Pacific white shrimp Litopenaeus vannamei (L. vannamei), understanding the impact of marine Cr pollution is deemed to be significant. In this study, we used the transcriptome sequencing (RNA-seq) technique to characterize the molecular mechanism of Cr exposure in L. vannamei. Gene ontology enrichment analysis showed substrate-specific and ion transport-related functions were mainly influenced by Cr exposure. We further identified genes involved in protein digestion and absorption (PEPT1, BAT1, MDU1), chemical carcinogenesis (GST and UGTs), ABC transporters (ABCC2), apoptosis (CAPN1, CASP10, PARP), implying the potentially Cr disintoxication mechanisms in L. vannamei. Genes within pancreatic secretion (ALT, LDH), lysosome (CTSL and HEXB), and peroxisome (ACOX1, ECI2, NUDT12) pathways implied the potentially Cr toxicity mechanisms in L. vannamei.


Assuntos
Cromo , Penaeidae , Animais , Cromo/toxicidade , Perfilação da Expressão Gênica , Ontologia Genética , Penaeidae/genética , Transcriptoma
14.
Toxicol Lett ; 333: 261-268, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32866567

RESUMO

Chromium (Cr) (VI) is a proven toxin, mutagen and carcinogen. Here, the role of high mobility group A2 (HMGA2) mediating Cr (VI)-induced mitophagy was investigated. Cr (VI)-treatment caused the formation of double membrane autophagic vesicles (AVs) engulfing mitochondria and increased the expression of PINK1, PARK2, LC3 as well as HMGA2 particularly in mitochondria in A549 cells. Silencing of HMGA2 by siRNA decreased expression of PINK1, PARK2 and LC3 II especially in mitochondria, while over-expression of HMGA2 increased the expression of them in A549 cells. It indicated that HMGA2 played a critical role in Cr (VI)-induced mitophagy. Most importantly, the results of co-immunoprecipitation showed for the first time that HMGA2 could bind to PARK2 in mitochondria to activate the mitophagy pathway. In BALB/c mice, Cr (VI) increased the expression of PINK1 and PARK2 in lung tissues. Furthermore, over-expression of HMGA2 in BALB/c mice by transfection of plasmid HMGA2 significantly increased the levels of PINK1, PARK2 and LC3 II in lung tissues. Collectively, our data demonstrated that HMGA2 plays an important role in Cr (VI)-induced mitophagy through direct interaction with PARK2 in A549 cells and lung tissue.


Assuntos
Cromo/toxicidade , Poluentes Ambientais/toxicidade , Proteína HMGA2/metabolismo , Pulmão/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Ubiquitina-Proteína Ligases/metabolismo , Células A549 , Animais , Expressão Gênica/efeitos dos fármacos , Células HEK293 , Proteína HMGA2/genética , Humanos , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Transporte Proteico , Transfecção , Ubiquitina-Proteína Ligases/genética
15.
Ecotoxicol Environ Saf ; 203: 110928, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888618

RESUMO

Hexavalent chromium [Cr(VI)] is seriously harmful to ecosystems and living organisms due to its strong toxicity. Role of dynamin-related protein 1 (Drp1) and Drp1-associated mitochondrial fragmentation in mitophagy and cytotoxicity after Cr(VI) exposure has not been clarified so far. We confirmed that Cr(VI) caused mitochondrial fission by up-regulating Drp1 expression and enhancing Drp1 mitochondrial translocation. By applying the intracellular Ca2+ antagonist BAPTA-AM and mitochondrial Ca2+ antagonist Ru360, we demonstrated that Cr(VI)-induced excessive mitochondrial fission was in a Ca2+-Drp1 dependent manner. The administration of Drp1 siRNA significantly suppressed the overactivation of mitophagy in Cr(VI)-induced hepatotoxicity. The specific Drp1 inhibitor mitochondrial division inhibitor-1 (Mdivi-1) blocked the overactive mitophagy and subsequently ameliorated hepatotoxicity caused by Cr(VI) in vivo. We reached the conclusion that Drp1-dependent mitochondrial fission contributes to Cr(VI)-induced mitophagy and hepatotoxicity, which may provide experimental basis for the study of chromium-associated toxicity, especially for the prevention of health damage in chromium-exposed population.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Cromo/toxicidade , Dinaminas/metabolismo , Poluentes Ambientais/toxicidade , Hepatócitos/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Animais , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ecossistema , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , RNA Interferente Pequeno/metabolismo
16.
Ecotoxicol Environ Saf ; 205: 111326, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32961495

RESUMO

Hexavalent chromium [Cr(VI)] is ubiquitous in the environment and is commonly used in various industrial processes. Clusterin (CLU) is an extracellular chaperone protein which exerts the anti-apoptotic function. In this study, we aimed to explore the effect of CLU on Cr(VI)-induced mitochondrial fission and apoptosis. We revealed that the apoptosis rate of L02 hepatocytes treated with Cr (VI) was increased. CLU over-expression could protect the hepatocytes from Cr(VI)-induced mitochondrial apoptosis. Furthermore, Cr(VI) triggered the intracellular calcium overload, resulting in the activation of xanthine oxidase (XO). Cr(VI) induced reactive oxygen species (ROS) overproduction, led to dynamin-related protein 1 (Drp1) translocation to mitochondria and the subsequent mitochondrial fission, contributing to the caspase-3-dependent mitochondrial apoptosis as evidenced by higher mitochondrial permeability transition pore (mPTP) opening rate, lower mitochondrial membrane potential (MMP), and more alanine transaminase (ALT)/aspartate transaminase (AST) leakage into the culture medium. However, CLU over-expression could trigger the AMP-activated protein kinase (AMPK) pathway, which was followed by the increase of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) expression. CLU-induced AMPK/SERCA2a activation attenuated calcium overload, caspase-3 activation, and ultimate mitochondrial apoptosis. All in all, the present study demonstrated that Cr(VI) induced hepatocytes apoptosis via Ca2+-ROS-Drp1-mitochondrial fission axis and CLU alleviated the mitochondrial apoptosis through activation of the AMPK/SERCA2a pathway.


Assuntos
Cromo/toxicidade , Clusterina/metabolismo , Poluentes Ambientais/toxicidade , Apoptose/efeitos dos fármacos , Caspase 3 , Dinaminas , Hepatócitos/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
17.
Aquat Toxicol ; 228: 105622, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947073

RESUMO

Hexavalent chromium, a heavy metal toxicant, abundantly found in the environment showed hepatotoxic potential in zebrafish liver and instigated the Nrf2-Keap1-ARE pathway as a cellular stress response as reported in our previous studies. In the present study we have evaluated the ameliorating effect of shinorine, a mycosporine like amino acid (MAAs) and a mammalian Keap1 antagonist against chromium induced stress in zebrafish hepatocytes. Shinorine was found to be effective in increasing the cell viability of chromium treated hepatocytes through curtailing the cellular ROS content. Trigonelline, an Nrf2 inhibitor was found to reduce the viability of hepatocyte cultures co-exposed to shinorine and chromium. In other words, trigonelline being an Nrf2 blocker neutralised the alleviating effect of shinorine. This indicated that shinorine mediated cyto-protection in Cr [VI]-intoxicated cells is Nrf2 dependent. Further, qRT-PCR analysis revealed comparatively higher expression of nfe2l2 and nqo1 in shinorine + chromium treated hepatocytes than cells exposed to chromium alone indicating a better functioning of Nrf2-Keap1-Nqo1 axis. To further confirm if shinorine can lead to disruption of Nrf2-Keap1 interaction in zebrafish hepatocytes and render cytoprotection to chromium exposure, our in silico analysis through molecular docking revealed that shinorine could bind to the active amino acid residues of the DGR domain, responsible for Nrf2-Keap1 interaction of all the three Keap1s evaluated. This is the first report about shinorine that ameliorates chromium induced toxicity through acting as an Nrf2-Keap1 interaction disruptor. We additionally carried out in-silico pharmacokinetic and ADMET studies to evaluate druglikeness of shinorine whose promising results indicated its potential to be developed as an ideal therapeutic candidate against toxicant induced pathological conditions.


Assuntos
Cromo/toxicidade , Cicloexilaminas/farmacologia , Glicina/análogos & derivados , Hepatócitos/efeitos dos fármacos , Proteína 1 Associada a ECH Semelhante a Kelch/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/metabolismo , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cianobactérias/metabolismo , Cicloexilaminas/isolamento & purificação , Glicina/isolamento & purificação , Glicina/farmacologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Simulação de Acoplamento Molecular , Estresse Oxidativo/efeitos dos fármacos , Cultura Primária de Células , Transdução de Sinais
18.
Bull Environ Contam Toxicol ; 105(3): 397-404, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32747993

RESUMO

Sensitivity of tropical freshwater microalgae (Mesotaenium sp., Chlorococcum sp. and Scenedesmus sp.) to environmentally relevant concentrations of hexavalent chromium (Cr6+) and cadmium (Cd2+) was compared individually in three growth media viz. Bold's Basal Medium (BBM), Test Medium 1 (TM1) and Test Medium 2 (TM2) based on fluorescence reduction. Free metal content of growth media was determined by Visual MINTEQ (version 3.1). After 24 h, relative fluorescence of microalgae in the three media decreased with increased metal concentration showing a concentration dependent graded toxicity response. All microalgae were more sensitive to the metals when grown in TM1, when compared, more sensitive to Cr6+ than Cd2+. Metal speciation indicated that TM1 and TM2 media have higher percentage of bioavailable Cd2+ than BBM, and chromium was present mainly as CrO42- and HCrO4-. The results suggest that the TM1 medium is more suitable under short term exposure of microalgae to metals in environmental monitoring.


Assuntos
Cádmio/toxicidade , Cromo/toxicidade , Microalgas/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Cádmio/análise , Cromo/análise , Meios de Cultura , Monitoramento Ambiental/métodos , Água Doce , Scenedesmus , Poluentes Químicos da Água/análise
19.
Ecotoxicol Environ Saf ; 204: 111061, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32750588

RESUMO

The use of hexavalent chromium (Cr(VI)) in many industrial processes has resulted in serious environmental pollution problems. Cr(VI) causes organ toxicity in animals after ingestion or inhalation. However, the exact mechanism by which Cr(VI) produces kidney damage remains elusive. Herein, we investigated whether Cr(VI)-induced kidney damage is related to the disorder of mitochondrial dynamics. In this study, 28 male rats were divided into four groups and intraperitoneally injected with 0, 2, 4, and 6 mg/kg body weight potassium dichromate for 5 weeks. Experiment included analysis of renal histopathology and ultrastructure, determination of biochemical indicators, and measurement of related protein content. The results showed that Cr(VI) induced kidney injury through promotion of oxidative stress, apoptosis, and disorder of mitochondrial dynamics in a dose-dependent manner. The protein levels of the silent information regulator two ortholog 1 (Sirt1), peroxisome proliferation-activated receptor-g coactivator-1a (PGC-1a), and autophagy-related proteins were significantly decreased after Cr(VI) exposure. These findings suggest that Cr(VI) leads to the disorder of mitochondrial dynamics by inhibiting the Sirt1/PGC-1a pathway, which leads to renal apoptosis and autophagy in rats.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cromo/toxicidade , Rim/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Rim/metabolismo , Rim/ultraestrutura , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Nefropatias/patologia , Masculino , Dicromato de Potássio/toxicidade , Ratos , Ratos Wistar
20.
Environ Pollut ; 267: 115379, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32841910

RESUMO

Chromium has been proven to be extremely phytotoxic. This study explored the impacts of increasing Cr(VI) exposure (up to 10 mg L-1 K2Cr2O7) on the growth and development of alfalfa plants and adaptation responses employed, in an environmentally relevant context. The threshold concentration of K2Cr2O7 in irrigation water beyond which stress responses are initiated is 1 mg L-1. Lower Cr(VI) exposure (0.5 mg L-1 K2Cr2O7) induced hormesis, evident through increased biomass and larger leaves, likely mediated by increased NO content (supported by elevated NR enzymatic activity and overexpression of NR and ndh genes). Elevated Cr(VI) exposure (5 and 10 mg L-1 K2Cr2O7) resulted in reduced biomass and smaller leaves, and lower levels of photosynthetic pigment (10 mg L-1 K2Cr2O7). Higher levels of lipid peroxidation, H2O2 and NO contents in these plants suggested nitro-oxidative stress. Stress responses included increased SOD and CAT enzymatic activities, further supported to some extent by MnSOD, FeSOD, Cu/ZnSOD and CAT transcripts levels. GST7 and GST17 gene expression patterns, as well as proline content, P5CS enzymatic activity and corresponding P5CS and P5CR gene expression levels emphasized the role of proline and GSTs in the adaptation responses. Results highlight the importance of managing Cr(VI) levels in irrigation water.


Assuntos
Hormese , Medicago sativa , Antioxidantes , Cromo/toxicidade , Peróxido de Hidrogênio , Estresse Oxidativo , Prolina
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