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1.
Ecotoxicology ; 31(5): 746-760, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35364763

RESUMO

Nickel acts as an essential trace nutrient or toxicant for organisms, depending on its concentration. The increased concentrations of nickel, due to anthropogenic activity, in the aquatic environment are potential threats to aquatic organisms. However, the knowledge on toxic mechanisms of nickel to microalgae remains incompletely understood. In the present study, we investigated the toxic effects of nickel in the cosmopolitan diatom Phaeodactylum tricornutum via evaluation of physiological and transcriptome responses. The results showed that the median effective concentration-72 h (EC50-72 h) and EC50-96 h of nickel was 2.48 ± 0.33 and 1.85 ± 0.17 mg/L, respectively. The P. tricornutum cell abundance and photosynthesis significantly decreased by 1 mg/L of nickel. Results from photosynthetic parameters including efficiency of the oxygen evolving complex (OEC) of photosystem II (PSII) (Fv/F0), maximum photosynthetic efficiency of PS II (Fv/Fm), electron transport rate (ETR), actual photosynthetic efficiency of PS II (Y(II)), non-photochemical quenching (NPQ), and photochemical quenching (qP) indicated that OEC of PS II might be impaired by nickel. The transcriptome data also reveal that OEC apparatus coding gene PS II oxygen-evolving enhancer protein 2 (PsbP) was regulated by nickel. Moreover, induced reactive oxygen species (ROS) production and chlorophyll a content were also detected under nickel stress. Transcriptome analysis revealed that nickel affected a variety of differentially expressed genes (DEGs) that involved in redox homeostasis, nitrogen metabolisms, fatty acids, and DNA metabolism. However, thiol-disulfide redox system might play important roles in nickel-induced oxidative stress resistance. This study improved the understanding of the toxic effect of nickel on the diatom P. tricornutum.


Assuntos
Diatomáceas , Microalgas , Clorofila/metabolismo , Clorofila A/metabolismo , Clorofila A/farmacologia , Diatomáceas/fisiologia , Níquel/metabolismo , Oxigênio/metabolismo , Fotossíntese , Complexo de Proteína do Fotossistema II
2.
BMC Genomics ; 17: 29, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26732698

RESUMO

BACKGROUND: Harmful algal blooms (HABs) caused by the dinoflagellate Cochlodinium polykrikoides lead to severe environmental impacts in oceans worldwide followed by huge economic losses. Algicide agent copper sulfate (CuSO4) is regard as an economical and effective agent for HABs mitigation; its biochemical and physiological effects were revealed in C. polykrikoides. However, molecular mechanisms of CuSO4 effect on the C. polykrikoides, even other HAB species, have not been investigated. The present study investigated the transcriptional response of C. polykrikoides against CuSO4 treatments, with the aim of providing certain molecular mechanism of CuSO4 effect on the C. polykrikoides blooms. RESULTS: RNA-seq generated 173 million reads, which were further assembled to 191,212 contigs. 43.3 %, 33.9 %, and 15.6 % of contigs were annotated with NCBI NR, GO, and KEGG database, respectively. Transcriptomic analysis revealed 20.6 % differential expressed contigs, which grouped into 8 clusters according to K-means clustering analysis, responding to CuSO4; 848 contigs were up-regulated and 746 contigs were down-regulated more than 2-fold changes from 12 h to 48 h exposure. KEGG pathway analysis of eukaryotic homologous genes revealed the differentially expressed genes (DEGs) were involved in diverse pathway; amongst, the genes involved in the translation, spliceosome, and/or signal transduction genes were highly regulated. Most of photosystem related genes were down-regulated and most of mitochondria related genes were up-regulated. In addition, the genes involved in the copper ion binding or transporting and antioxidant systems were identified. Measurement of chlorophyll fluorescence showed that photosynthesis was significantly inhibited by CuSO4 exposure. CONCLUSIONS: This study reported the first transcriptome of the C. polykrikoides. The widely differential expressed photosystem genes suggested photosynthetic machinery were severely affected, and may further contribute to the cell death. Furthermore, gene translation and transcription processes may be disrupted, inhibiting cell growth and proliferation, and possibly accelerating cell death. However, antioxidant systems resistant to CuSO4 caused stress; mitochondrion may compensate for photosynthesis efficiency decreasing caused energy deficiency. In addition, various signal transduction pathways may be involved in the CuSO4 induced regulation network in the C. polykrikoides. These data provide the potential transcriptomic mechanism to explain the algicide CuSO4 effect on the harmful dinoflagellate C. polykrikoides.


Assuntos
Bixaceae/genética , Sulfato de Cobre/farmacologia , Genoma , Transcriptoma/efeitos dos fármacos , Antioxidantes/farmacologia , Bixaceae/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Proliferação Nociva de Algas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
3.
Ecotoxicol Environ Saf ; 133: 501-8, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27552343

RESUMO

Chlorine (Cl2) is widely used as a disinfectant in water treatment plants and for cleaning swimming pools; it is finally discharged into aquatic environments, possibly causing damage to the non-target organisms in the receiving water bodies. Present study evaluated the effects of the biocide Cl2 to the green alga Closterium ehrenbergii (C. ehrenbergii). Growth rate, chlorophyll a levels, carotenoids, chlorophyll autofluorescence, and antioxidant enzymes were monitored up to 72-h after Cl2 exposure. C. ehrenbergii showed dose-dependent decrease in growth rate and cell division after exposure to Cl2. By using cell counts, the median effective concentration (EC50)-72-h was calculated to be 0.071mgL(-1). Cl2 significantly decreased the pigment levels and chlorophyll autofluorescence intensity, indicating that the photosystem was damaged in C. ehrenbergii. In addition, it increased the production of reactive oxygen species (ROS) in the cells. This stressor significantly increased the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase, and glutathione, and affected the physiology of the cells. These results indicate that Cl2 induces oxidative stress in the cellular metabolic process and leads to physiological and biochemical damages in the green algae. Cl2 discharged in industrial effluents and from water treatment plants may cause harmful effects to the C. ehrenbergii a common freshwater microalgae and other non-target organisms.


Assuntos
Cloro/toxicidade , Closterium/efeitos dos fármacos , Desinfetantes/toxicidade , Exposição Ambiental/efeitos adversos , Água Doce/química , Estresse Oxidativo/efeitos dos fármacos , Água/química , Antioxidantes/metabolismo , Organismos Aquáticos , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila/análogos & derivados , Clorofila/metabolismo , Clorofila A , Clorófitas/metabolismo , Closterium/fisiologia , Glutationa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
4.
Mol Biol Rep ; 42(3): 681-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25398213

RESUMO

Calreticulin is a multifunctional Ca(2+)-binding protein that has been well characterised in mammalian cells. Here, we characterised a novel calreticulin (CRT2) gene in the dinoflagellate Prorocentrum minimum, which codes for a calcium binding protein and examined its expression pattern following the addition of calcium and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). PmCRT2 is encoded in the nuclear genome of P. minimum without introns. The full length cDNA of PmCRT2 was found to be 1,493 base pairs (bp) in length, which ranges from the dinoflagellate spliced leader sequence to the poly (A) tail and contains a 1,173-bp open reading frame, a 70-bp 5'-untranslated region (UTR), and a 207-bp 3'-UTR. On the basis of in silico analyses that revealed the distinct domain architectures of PmCRT2, we classified this protein under the calreticulin family. PmCRT2 gene expression was up-regulated in the presence of excess calcium in a dose-dependent manner; however, PmCRT2 expression was down-regulated by the addition of EGTA. These results clearly indicate that PmCRT2 plays a vital role in calcium regulation and this may be involved in the stress response of P. minimum.


Assuntos
Calreticulina/genética , Dinoflagellida/genética , Expressão Gênica , Sequência de Aminoácidos , Sequência de Bases , Calreticulina/química , Calreticulina/metabolismo , Clonagem Molecular , Dinoflagellida/classificação , Dinoflagellida/metabolismo , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA
5.
Ecotoxicology ; 24(4): 863-72, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25724346

RESUMO

The green alga Closterium ehrenbergii occurs in fresh water environments and has been suggested as a model for ecotoxicological assessment. Quantitative real-time PCR (qRT-PCR), with its high sensitivity and specificity, is a preferred method for reliable quantification of gene expression levels. qRT-PCR requires reference genes to normalize the transcription level of the target gene, and selection of appropriate references is crucial. Here, we evaluated nine housekeeping genes, that is, 18S rRNA, ACT, TUA, TUB, eIF, H4, UBQ, rps4, and GAPDH, using 34 RNA samples of C. ehrenbergii cultured in various environments (e.g. exposure to heat shock, UV, metals, and non-metallic chemicals). Each housekeeping gene tested displayed different ranges of C T values for each experimental condition. The gene stability was determined using the descriptive statistic software geNorm, which showed that ACT, H4, and TUA were the most suitable reference genes for all the conditions tested. In addition, at least three genes were required for proper normalization. With these references, we assessed the expression level of the heat shock protein 70 (HSP70) gene in C. ehrenbergii cells exposed to thermal and toxic contaminant stress and found that it was significantly up-regulated by these stressors. This study provides potential reference genes for gene expression studies on C. ehrenbergii with qRT-PCR.


Assuntos
Proteínas de Algas/genética , Closterium/genética , Ecotoxicologia/métodos , Expressão Gênica , Genes Essenciais , Toxicogenética/métodos , Proteínas de Algas/metabolismo , Closterium/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
6.
Environ Toxicol ; 29(12): 1379-89, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23661567

RESUMO

Diatoms are sensitive indicators of water quality, and hence used for environmental hazard assessments; however, their toxicogenomic studies have been insufficiently attempted. In the present study, we determined the cDNA sequence of heat shock protein 20 (Hsp20) gene from the diatom Ditylum brightwellii, and examined the transcriptional responses of the gene after exposing it to environmental stressors such as thermal shock, metals, and endocrine-disrupting chemicals (EDCs). The open reading frame (ORF) of DbHsp20 was 531 bp long, encoding 177 amino acid residues (19.49 kDa) with a conserved C-terminal and α-crystallin domain. The genomic region of DbHsp20 did not contain introns. Phylogeny of eukaryotic Hsp20s showed D. brightwellii was closely related to other diatoms. With regard to the gene expressional profile, real-time PCR results showed that the gene was significantly upregulated (P < 0.001) under thermal stress, with the highest change of 3.2-fold. Metals' (copper and nickel) treatments showed that it was induced after a certain point of treated concentration. On the contrary, EDCs did not display noticeable change on the expression of DbHsp20. These results suggest that the diatom Hsp20 basically responds to thermal stress, but may differentially respond to toxic substances such as metals and organic compounds such as EDCs.


Assuntos
Diatomáceas/efeitos dos fármacos , Disruptores Endócrinos/farmacologia , Poluentes Ambientais/farmacologia , Proteínas de Choque Térmico HSP20/genética , Metais/farmacologia , Cobre/farmacologia , Diatomáceas/genética , Diatomáceas/metabolismo , Proteínas de Choque Térmico HSP20/classificação , Proteínas de Choque Térmico HSP20/metabolismo , Filogenia , Transcrição Gênica/efeitos dos fármacos
7.
Med Image Anal ; 97: 103273, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39029157

RESUMO

Fundus image quality serves a crucial asset for medical diagnosis and applications. However, such images often suffer degradation during image acquisition where multiple types of degradation can occur in each image. Although recent deep learning based methods have shown promising results in image enhancement, they tend to focus on restoring one aspect of degradation and lack generalisability to multiple modes of degradation. We propose an adaptive image enhancement network that can simultaneously handle a mixture of different degradations. The main contribution of this work is to introduce our Multi-Degradation-Adaptive module which dynamically generates filters for different types of degradation. Moreover, we explore degradation representation learning and propose the degradation representation network and Multi-Degradation-Adaptive discriminator for our accompanying image enhancement network. Experimental results demonstrate that our method outperforms several existing state-of-the-art methods in fundus image enhancement. Code will be available at https://github.com/RuoyuGuo/MDA-Net.

8.
J Cancer ; 15(9): 2746-2758, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38577602

RESUMO

Purpose: To explore the effects of miR-383-5p and serine hydroxymethyltransferase 2 (SHMT2) on the proliferation and migration of lung adenocarcinoma cells. Methods: SHMT2 expression in lung adenocarcinoma and normal tissues was investigated using The Cancer Genome Atlas database. Immunohistochemical analysis was performed to confirm SHMT2 expression in lung adenocarcinoma and adjacent normal lung tissues. Bioinformatics analysis and luciferase reporter assays were used to analyze the relationship between miR-383-5p and SHMT2 expression. The protein expression levels of SHMT2, vimentin, N-cadherin, E-cadherin, Bcl-2, and cyclinD1 were analyzed using western blotting. The reverse transcription-quantitative polymerase chain reaction was used to detect SHMT2 knockdown efficiency, miR-383-5p overexpression, and inhibition efficiency. The proliferative ability of cells was detected using the Cell Counting Kit-8 assay. The Transwell assay was used to detect the migration ability of cells. Results: SHMT2 expression was significantly increased in patients with lung adenocarcinoma compared to that in control patients; the higher the SHMT2 expression the worse the outcomes were in patients with lung adenocarcinoma. SHMT2 knockdown inhibited the proliferation, migration, and epithelial-mesenchymal transition of lung adenocarcinoma A549 and H1299 cells. MiR-383-5p directly targeted and downregulated SHMT2 in A549 and H1299 cells. The effects of miRNA-383-5p on the proliferation and migration of these cells differed from those of SHMT2. Exogenous overexpression of SHMT2 reversed the miR-383-5p-induced proliferation and migration inhibition in A549 and H1299 cells. Conclusion: MiR-383-5p inhibits the proliferation and migration of lung adenocarcinoma cells by targeting and downregulating SHMT2.

9.
Med Oncol ; 41(9): 212, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073639

RESUMO

Diffuse large B-cell lymphoma (DLBCL) is a genetically heterogeneous non-Hodgkin lymphoma that is extremely aggressive and has an intermediate to high malignancy. Some patients still experience treatment failure, relapse, or resistance to rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) therapy. Therefore, there is an urgent need for further research on new agents for the treatment of DLBCL. AP-48 is an aaptamine alkaloid analog with potent anti-tumor effects that originates from marine natural products. In this study, we found that AP-48 exhibits dose-dependent cytotoxicity in DLBCL cell lines. Flow cytometry showed that AP-48 induced cell cycle arrest in the G0/G1 phase in SU-DHL-4 and Farage cells and in the S phase in WSU-DLCL-2 cells. AP-48 also accelerated apoptosis via the caspase-3-mediated intrinsic apoptotic pathway. Further experiments demonstrated that AP-48 exerted its anti-DLBCL effects through the PI3K/AKT/mTOR pathway, and that the PI3K agonist YS49 partially alleviated the inhibition of cell proliferation and apoptosis induced by AP-48. Finally, in a tumor xenograft model, AP-48 inhibited tumor growth and promoted apoptosis in tumor tissues, indicating its therapeutic potential in DLBCL.


Assuntos
Alcaloides , Apoptose , Linfoma Difuso de Grandes Células B , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Serina-Treonina Quinases TOR , Ensaios Antitumorais Modelo de Xenoenxerto , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/metabolismo , Humanos , Serina-Treonina Quinases TOR/metabolismo , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Alcaloides/farmacologia , Linhagem Celular Tumoral , Camundongos , Apoptose/efeitos dos fármacos , Poríferos/química , Camundongos Nus , Proliferação de Células/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Antineoplásicos/farmacologia
10.
Med Image Anal ; 86: 102790, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36878159

RESUMO

Deep convolutional neural networks have been highly effective in segmentation tasks. However, segmentation becomes more difficult when training images include many complex instances to segment, such as the task of nuclei segmentation in histopathology images. Weakly supervised learning can reduce the need for large-scale, high-quality ground truth annotations by involving non-expert annotators or algorithms to generate supervision information for segmentation. However, there is still a significant performance gap between weakly supervised learning and fully supervised learning approaches. In this work, we propose a weakly-supervised nuclei segmentation method in a two-stage training manner that only requires annotation of the nuclear centroids. First, we generate boundary and superpixel-based masks as pseudo ground truth labels to train our SAC-Net, which is a segmentation network enhanced by a constraint network and an attention network to effectively address the problems caused by noisy labels. Then, we refine the pseudo labels at the pixel level based on Confident Learning to train the network again. Our method shows highly competitive performance of cell nuclei segmentation in histopathology images on three public datasets. Code will be available at: https://github.com/RuoyuGuo/MaskGA_Net.


Assuntos
Algoritmos , Núcleo Celular , Humanos , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador
11.
Int Immunopharmacol ; 120: 110417, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37276826

RESUMO

Immunotherapy based on immune checkpoint inhibitors (ICIs) has revolutionized treatment strategies in multiple types of cancer. However, the resistance and relapse as associated with the extreme complexity of cancer-immunity interactions remain a major challenge to be resolved. Owing to the epigenome plasticity of cancer and immune cells, a growing body of evidence has been presented indicating that epigenetic treatments have the potential to overcome current limitations of immunotherapy, thus providing a rationalefor the combination of ICIs with epigenetic agents (epidrugs). In this review, we first make an overview about the epigenetic regulations in tumor biology and immunodevelopment. Subsequently, a diverse array of inhibitory agents under investigations targeted epigenetic modulators (Azacitidine, Decitabine, Vorinostat, Romidepsin, Belinostat, Panobinostat, Tazemetostat, Enasidenib and Ivosidenib, etc.) and immune checkpoints (Atezolizmab, Avelumab, Cemiplimab, Durvalumb, Ipilimumab, Nivolumab and Pembrolizmab, etc.) to increase anticancer responses were described and the potential mechanisms were further discussed. Finally, we summarize the findings of clinical trials and provide a perspective for future clinical studies directed at investigating the combination of epidrugs with ICIs as a treatment for cancer.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias/tratamento farmacológico , Nivolumabe/uso terapêutico , Ipilimumab/uso terapêutico , Imunoterapia
12.
ISME J ; 17(11): 1979-1992, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37679430

RESUMO

Algae and bacteria have complex and intimate interactions in the ocean. Besides mutualism, bacteria have evolved a variety of molecular-based anti-algal strategies. However, limited by the unknown mechanism of synthesis and action of these molecules, these strategies and their global prevalence remain unknown. Here we identify a novel strategy through which a marine representative of the Gammaproteobacteria produced 3,3',5,5'-tetrabromo-2,2'-biphenyldiol (4-BP), that kills or inhibits diverse phytoplankton by inhibiting plastoquinone synthesis and its effect cascades to many other key metabolic processes of the algae. Through comparative genomic analysis between the 4-BP-producing bacterium and its algicidally inactive mutant, combined with gene function verification, we identified the gene cluster responsible for 4-BP synthesis, which contains genes encoding chorismate lyase, flavin-dependent halogenase and cytochrome P450. We demonstrated that in near in situ simulated algal blooming seawater, even low concentrations of 4-BP can cause changes in overall phytoplankton community structure with a decline in dinoflagellates and diatoms. Further analyses of the gene sequences from the Tara Oceans expeditions and 2750 whole genome sequences confirmed the ubiquitous presence of 4-BP synthetic genes in diverse bacterial members in the global ocean, suggesting that it is a bacterial tool potentially widely used in global oceans to mediate bacteria-algae antagonistic relationships.


Assuntos
Bactérias , Plastoquinona , Plastoquinona/metabolismo , Plastoquinona/farmacologia , Bactérias/genética , Bactérias/metabolismo , Oceanos e Mares , Água do Mar/microbiologia , Fitoplâncton/metabolismo
13.
Ecotoxicology ; 21(5): 1448-57, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22476698

RESUMO

The dinoflagellate algae survive variations in water temperature as well as sudden exposures to toxic substances; heat shock proteins (HSPs) seem to function as part of their cell survival strategy. In the present study, we determined the complete open reading frame (ORF) of HSP90 gene in the dinoflagellate Prorocentrum minimum (PmHSP90), and examined the expression levels of the gene after exposure to thermal stressors, copper metal, and endocrine-disrupting chemicals, including bisphenol A (BPA) and polychlorinated biphenyl (PCB). The complete ORF of PmHSP90 was 2,130-bp long, encoding a 709-amino acid-long polypeptide (81.62 kDa), and bearing characteristics of the HSP90 family and conserved domains. Real-time (RT)-PCR analyses revealed different expression patterns after exposure to heat, metals, and chemicals. The expression of PmHSP90 was significantly upregulated by increased thermal stresses, with the highest changes of 2.4-fold and 1.9-fold occurring after 24 h at 25 °C and 30 °C, respectively. The gene expression dramatically increased (2.1 to 8.9-fold changes) with increasing concentrations of copper (one-way ANOVA, P < 0.01). Treatment with BPA or PCB, however, did not induce significant changes in PmHSP90 expression. These data suggest that the dinoflagellate HSP90 responds to thermal stressors, but may differentially respond to toxic substances such as metals and endocrine-disrupting chemicals.


Assuntos
Cobre/toxicidade , Dinoflagellida/efeitos dos fármacos , Dinoflagellida/genética , Disruptores Endócrinos/toxicidade , Proteínas de Choque Térmico HSP90/genética , Sequência de Aminoácidos , Dinoflagellida/metabolismo , Expressão Gênica , Proteínas de Choque Térmico HSP90/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Estresse Fisiológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Toxics ; 10(5)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35622625

RESUMO

Nickel and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) are two environmental pollutants commonly and simultaneously present in aquatic systems. Nickel and BDE-47 are individually toxic to various aquatic organisms. However, their toxicity mechanisms are species-dependent, and the toxic effects of combined mixtures of BDE-47 and nickel have not yet been investigated. The present study investigated the toxic effects of combined mixtures of BDE-47 and nickel in the diatom Phaeodactylum tricornutum. BDE-47 and nickel mixtures significantly decreased cell abundance and photosynthetic efficiency, while these cells' reactive oxygen species (ROS) production significantly increased. The EC50-72 h for BDE-47 and mixtures of BDE-47 and nickel were 16.46 ± 0.93 and 1.35 ± 0.06 mg/L, respectively. Thus, combined mixtures of the two pollutants enhance their toxic effects. Interactions between BDE-47 and nickel were evaluated, revealing synergistic interactions that contributed to toxicity in P. tricornutum. Moreover, transcriptomic analyses revealed photosynthesis, nitrogen metabolism, the biosynthesis of amino acids, the biosynthesis of secondary metabolites, oxoacid metabolism, organic acid metabolism, carboxylic acid metabolism, and oxidation-reduction processes were considerably affected by the mixtures. This study provides evidence for the mechanisms of toxicity from combined BDE-47 and nickel exposure while also improving our understanding of the ecological risks of toxic chemicals on microalgae.

15.
Toxins (Basel) ; 14(2)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35202121

RESUMO

As a marine ichthyotoxic dinoflagellate, Margalefidinium polykrikoides, previously named Cochlodinium polykrikoides, have caused mass mortalities of fish worldwide during blooms. Rapid detection of target species is a prerequisite for the timely monitoring and early warning of harmful algal blooms (HABs). However, it is difficult to achieve rapid identification with traditional methods. The technology of using quantitative real-time PCR (qPCR) to detect and quantify microalgae is relatively mature. Based on the accuracy, rapidity, and sensitivity of qPCR technology, it can be used in the monitoring and development of early warning systems for HABs. From 2017 to 2020, samples were collected from 15 locations off the Chinese coast or from local sea areas. Based on the qPCR detection and analysis, the target species, M. polykrikoides (East Asian ribotype, EAr), was found in samples from Tianjin, Yangtze River estuary, and offshore Fujian (East China Sea). This is the first time that M. polykrikoides (EAr) was detected in the coastal waters of Tianjin. The results reveal a distributive pattern of M. polykrikoides (EAr) along Chinese coastal waters. It is helpful to predict the future diffusion trend of M. polykrikoides (EAr) in the China Sea and provides a practical case for the future construction of monitoring and warning systems for M. polykrikoides and HABs.


Assuntos
Dinoflagellida/isolamento & purificação , China , Dinoflagellida/genética , Dinoflagellida/ultraestrutura , Monitoramento Ambiental , Estuários , Proliferação Nociva de Algas , Microscopia Eletrônica de Varredura , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Ribotipagem , Água do Mar
16.
Front Microbiol ; 13: 1041521, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36406446

RESUMO

In oceanic oxygen minimum zones (OMZs), the abundances of aerobic organisms significantly decrease and energy shifts from higher trophic levels to microorganisms, while the microbial communities become critical drivers of marine biogeochemical cycling activities. However, little is known of the microbial ecology of the Andaman Sea and eastern Bay of Bengal (BoB) OMZs. In the present study, a total of 131 samples which from the Andaman Sea and eastern BoB epipelagic waters were analyzed. The microbial community distribution patterns across oxygen gradients, including oxygenic zones (OZs, dissolved oxygen [DO] ≥ 2 mg/L), oxygen limited zones (OLZs, 0.7 mg/L < DO < 2 mg/L), and OMZs (DO ≤ 0.7 mg/L), were investigated. Mantel tests and Spearman's correlation analysis revealed that DO was the most important driver of microbial community structures among several environmental factors. Microbial diversity, richness, and evenness were highest in the OLZs and lowest in the OZs. The microbial community compositions of OZ and OMZ waters were significantly different. Random forest analysis revealed 24 bioindicator taxa that differentiated OZ, OLZ, and OMZ water communities. These bioindicator taxa included Burkholderiaceae, HOC36, SAR11 Clade IV, Thioglobaceae, Nitrospinaceae, SAR86, and UBA10353. Further, co-occurrence network analysis revealed that SAR202, AEGEAN-169, UBA10353, SAR406, and Rhodobacteraceae were keystone taxa among the entire interaction network of the microbial communities. Functional prediction further indicated that the relative abundances of microbial populations involved in nitrogen and sulfur cycling were higher in OMZs. Several microbial taxa, including the Thioglobaceae, Nitrospinaceae, SAR202, SAR406, WPS-2, UBA10353, and Woeseiaceae, may be involved in nitrogen and/or sulfur cycling, while also contributing to oxygen consumption in these waters. This study consequently provides new insights into the microbial community structures and potentially important taxa that contribute to oxygen consumption in the Andaman Sea and eastern BoB OMZ.

17.
Mol Biol Rep ; 38(1): 49-58, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20238169

RESUMO

WRKY proteins play important roles in plant defense responses. In the present study, a novel WRKY gene, nominated as GhWRKY3, was isolated from cotton (Gossypium hirsutum L.). The full-length cDNA of GhWRKY3 is 1,705 bp in length and encodes a protein with 507 amino acids containing two typical WRKY domains and two zinc finger motifs. Amino acid sequence alignment revealed that GhWRKY3 shares a high degree of identity with other higher plant WRKY proteins. The subcellular localization assay indicated that GhWRKY3 is localized to the nucleus. Analysis of 5'-flanking region of GhWRKY3 revealed a group of putative cis-acting elements. The results of expression analysis indicated that GhWRKY3 is constitutively expressed in roots, stems and leaves. Semi-quantitative RT-PCR showed that GhWRKY3 is up-regulated by application of various phytohormones including salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), gibberellins (GAs) and ethylene (ET). Furthermore, the transcripts of GhWRKY3 are enhanced after infection with Rhizoctonia solani, Colletotrichum gossypii and Fusarium oxysporum f. sp. vasinfectum, respectively. Also, GhWRKY3 can be induced by wounding treatment, but not by cytokinin (6-benzylaminopurine, 6-BA), auxin analogue, drought, NaCl, and cold (4°C). These data suggested that GhWRKY3 might play an important role in plant defense responses and fulfill a pivotal role in plant development.


Assuntos
Genes de Plantas/genética , Gossypium/genética , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Região 5'-Flanqueadora/genética , Núcleo Celular/metabolismo , Clonagem Molecular , DNA de Plantas/genética , Fungos/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Gossypium/microbiologia , Proteínas de Fluorescência Verde/metabolismo , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Filogenia , Proteínas de Plantas/metabolismo , Transporte Proteico , Proteínas Recombinantes de Fusão/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Análise de Sequência de DNA , Transdução de Sinais/genética , Frações Subcelulares/metabolismo , Transcrição Gênica
18.
Health Sci Rep ; 4(3): e376, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34541334

RESUMO

INTRODUCTION: Over the past decade, we have witnessed the initiation and implementation of precision medicine (PM), a discipline that promises to individualize and personalize medical management and treatment, rendering them ultimately more precise and effective. Despite of the continuing advances and numerous clinical applications, the potential of PM remains highly controversial, sparking heated debates about its future. METHOD: The present article reviews the philosophical issues and practical challenges that are critical to the feasibility and implementation of PM. OUTCOME: The explanation and argument about the relations between PM and computability, uncertainty as well as complexity, show that key foundational assumptions of PM might not be fully validated. CONCLUSION: The present analysis suggests that our current understanding of PM is probably oversimplified and too superficial. More efforts are needed to realize the hope that PM has elicited, rather than make the term just as a hype.

19.
Harmful Algae ; 93: 101777, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32307068

RESUMO

In the present study, we extensively characterized potential toxin-related genes, including polyketide synthase (PKS), saxitoxin (STX) and fatty acid synthase (FAS) from the non-toxin producing marine dinoflagellate Cochlodinium polykrikoides, comparing to those of a toxigenic dinoflagellate Alexandrium pacificum. RNA sequencing revealed 50 and 271 PKS contigs from C. polykrikoides and A. pacificum, respectively. According to domain constitute and amino acid alteration, we further classified the dinoflagellate type I PKS genes into 4 sub-groups. Type III PKS was first identified in C. polykrikoides. Interestingly, we detected a large number (242 and 288) of homologs of 18 sxt genes from two studied dinoflagellates. Most of the eight key genes (sxtA, sxtB, sxtD, sxtG, sxtH/T, sxtI, sxtS and sxtU) for STX synthesis were detected in both dinoflatellates, whereas a core STX biosynthesis gene sxtG was not detected in C. polykrikoides. This may partially explain the absence of saxitoxin production in C. polykrikoides. In addition, we identified several type I and type II FAS genes, including FabD, FabF, FabG, FabH, FabI, and FabZ, whereas FabB was not found in C. polykrikoides. Overall, the numbers of the toxin-related genes in C. polykrikoides were less than that of A. pacificum. Phylogenetic analyses showed that type I PKS/FASs of dinoflagellates had close relationships with apicomplexans and bacteria. These suggest that the toxin-related PKS and sxt genes are commonly present in toxigenic and non-toxin producing dinoflagellates, and may be involved not only in the toxin synthesis, but also in other related molecular metabolic functions.


Assuntos
Dinoflagellida , Dinoflagellida/genética , Filogenia , Policetídeo Sintases/genética , Saxitoxina , Transcriptoma
20.
Chemosphere ; 195: 398-409, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29274579

RESUMO

Endocrine disrupting chemicals (EDCs) have toxic effects on algae; however, their molecular genomic responses have not been sufficiently elucidated. Here, we evaluated genome-scaled responses of the dinoflagellate alga Prorocentrum minimum exposed to an EDC, polychlorinated biphenyl (PCB), using a 6.0 K microarray. Based on two-fold change cut-off, we identified that 609 genes (∼10.2%) responded to the PCB treatment. KEGG pathway analysis showed that differentially expressed genes (DEGs) were related to ribosomes, biosynthesis of amino acids, spliceosomes, and cellular processes. Many DEGs were involved in cell cycle progression, apoptosis, signal transduction, ion binding, and cellular transportation. In contrast, only a few genes related to photosynthesis and oxidative stress were expressed in response to PCB exposure. This was supported by that fact that there were no obvious changes in the photosynthetic efficiency and reactive oxygen species (ROS) production. These results suggest that PCB might not cause chloroplast and oxidative damage, but could lead to cell cycle arrest and apoptosis. In addition, various signal transduction and transport pathways might be disrupted in the cells, which could further contribute to cell death. These results expand the genomic understanding of the effects of EDCs on this dinoflagellate protist.


Assuntos
Dinoflagellida/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Bifenilos Policlorados/farmacologia , Transcriptoma/efeitos dos fármacos , Apoptose , Poluentes Ambientais/toxicidade , Análise em Microsséries , Transdução de Sinais/efeitos dos fármacos
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