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1.
Int J Cancer ; 151(6): 930-943, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-35657344

RESUMEN

Integrin α6 (ITGA6) forms integrin receptors with either integrin ß1 (ITGB1) or integrin ß4 (ITGB4). How it functions to regulate hepatocellular carcinoma (HCC) progression is not well-elucidated. We found that ITGA6 RNA and protein expression levels are significantly elevated in human HCC tissues in comparison with paired adjacent nontumor tissues by RNA sequencing, RT-qPCR, Western blotting and immunofluorescence staining. Stable knockdown of ITGA6 with different ITGA6 shRNA expression lentivectors significantly inhibited proliferation, migration and anchorage-independent growth of HCC cell lines in vitro, and xenograft tumor growth in vivo. The inhibition of anchorage-dependent and -independent growth of HCC cell lines was also confirmed with anti-ITGA6 antibody. ITGA6 knockdown was shown to induce cell-cycle arrest at G0/G1 phase. Immunoprecipitation assay revealed apparent interaction of ITGA6 with ITGB4, but not ITGB1. Expression studies showed that ITGA6 positively regulates the expression of ITGB4 with no or negative regulation of ITGB1 expression. Finally, while high levels of ITGA6 and ITGB4 together were associated with significantly worse survival of HCC patients in TCGA data set, the association was not significant for high levels of ITGA6 and ITGB1. In conclusion, ITGA6 is upregulated in HCC tumors and has a malignant promoting role in HCC cells through integrin α6ß4 complex. Thus, integrin α6ß4 may be a therapeutic target for treating patients with HCC.


Asunto(s)
Carcinoma Hepatocelular , Integrina alfa6 , Integrina alfa6beta4 , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Integrina alfa6/genética , Integrina alfa6/metabolismo , Integrina alfa6beta4/genética , Integrina alfa6beta4/metabolismo , Integrina beta4/genética , Integrina beta4/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología
2.
BMC Genomics ; 22(1): 228, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33794768

RESUMEN

BACKGROUND: The red panda (Ailurus fulgens) is a riddle of morphology, making it hard to tell whether it is an ursid, a procyonid, a mustelid, or a member of its own family. Previous genetic studies have given quite contradictory results as to its phylogenetic placement. RESULTS: A recently developed whole genome-based algorithm, the Whole Genome K-mer Signature algorithm was used to analyze the genomes of 28 species of Carnivora, including A. fulgens and several felid, ursid, mustelid, one mephitid species. This algorithm has the advantage of holistically using all the information in the genomes of these species. Being a genomics-based algorithm, it also reduces stochastic error to a minimum. Besides the whole genome, the mitochondrial DNA from 52 mustelids, mephitids, ursids, procyonids and A. fulgens were aligned to draw further phylogenetic inferences. The results from the whole genome study suggested that A. fulgens is a member of the mustelid clade (p = 9·10- 97). A. fulgens also separates from the mephitid Spilogala gracilis. The giant panda, Ailuropoda melanoleuca also clusters away from A. fulgens, together with other ursids (p = 1.2·10- 62). This could be due to the geographic isolation of A. fulgens from other mustelid species. However, results from the mitochondrial study as well as neighbor-joining methods based on the sequence identity matrix suggests that A. fulgens forms a monophyletic group. A Maximum Likelihood tree suggests that A. fulgens and Ursidae form a monophyletic group, although the bootstrap value is weak. CONCLUSIONS: The main conclusion that we can draw from this study is that on a whole genome level A. fulgens possibly belongs to the mustelid clade, and not an ursid or a mephitid. This despite the fact that previously some researchers classified A. fulgens and A. melanoleuca as relatives. Since the genotype determines the phenotype, molecular-based classification takes precedence over morphological classifications. This affirms the results of some previous studies, which studied smaller portions of the genome. However, mitochondrial analyses based on neighbor-joining and maximum likelihood methods suggest otherwise.


Asunto(s)
Ailuridae , Carnívoros , Ursidae , Ailuridae/genética , Animales , Carnívoros/genética , ADN Mitocondrial/genética , Filogenia , Ursidae/genética
3.
Int J Mol Sci ; 22(2)2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33450918

RESUMEN

The multimycotoxin-degrading efficiency of the Rhodococcus erythropolis NI1 strain was investigated with a previously developed three-step method. NI1 bacterial metabolites, single and combined mycotoxins and their NI1 degradation products, were injected into one cell stage zebrafish embryos in the same doses. Toxic and interaction effects were supplemented with UHPLC-MS/MS measurement of toxin concentrations. Results showed that the NI1 strain was able to degrade mycotoxins and their mixtures in different proportions, where a higher ratio of mycotoxins were reduced in combination than single ones. The NI1 strain reduced the toxic effects of mycotoxins and mixtures, except for the AFB1+T-2 mixture. Degradation products of the AFB1+T-2 mixture by the NI1 strain were more toxic than the initial AFB1+T-2 mixture, while the analytical results showed very high degradation, which means that the NI1 strain degraded this mixture to toxic degradation products. The NI1 strain was able to detoxify the AFB1, ZEN, T-2 toxins and mixtures (except for AFB1+T-2 mixture) during the degradation experiments, which means that the NI1 strain degraded these to non-toxic degradation products. The results demonstrate that single exposures of mycotoxins were very toxic. The combined exposure of mycotoxins had synergistic effects, except for ZEN+T-2 and AFB1+ZEN +T-2, whose mixtures had very strong antagonistic effects.


Asunto(s)
Micotoxinas/metabolismo , Rhodococcus/metabolismo , Pruebas de Toxicidad , Pez Cebra , Aflatoxina B1/metabolismo , Aflatoxina B1/farmacología , Aflatoxina B1/toxicidad , Animales , Bacterias/metabolismo , Relación Dosis-Respuesta a Droga , Dosificación Letal Mediana , Microinyecciones , Micotoxinas/toxicidad , Pruebas de Toxicidad/métodos , Zearalenona/metabolismo
4.
Acta Vet Hung ; 69(1): 23-30, 2021 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-33764891

RESUMEN

The purpose of the present study was to use oxidative stress markers for investigating the effect of zeolite (315 mg/kg of complete feed) in the case of aflatoxin B1 contamination (92 µg/kg complete feed). In a 21-day feeding trial with broiler chickens, oxidative stress parameters such as conjugated dienes, conjugated trienes, malondialdehyde, reduced glutathione content and glutathione peroxidase activity were not changed significantly by supplementation with this mycotoxin absorbent. The relative gene expression of transcription factors KEAP1 and NRF2 was not modified by the absorbent either. Still, the expression of GSS, GSR and GPX4 genes increased significantly due to the aluminosilicate supplementation. The results suggest that zeolite reduced lipid peroxidation in the blood plasma but not in the red blood cell haemolysate or the kidney. The relative expression of the genes encoding the glutathione redox system also changed as a result of zeolite supplementation, but these changes were not found at the protein level.


Asunto(s)
Aflatoxina B1 , Zeolitas , Aflatoxina B1/toxicidad , Alimentación Animal , Animales , Pollos/metabolismo , Genes Reguladores , Glutatión/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Hígado , Factor 2 Relacionado con NF-E2/genética , Zeolitas/farmacología
5.
Curr Microbiol ; 77(9): 2430-2440, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32504322

RESUMEN

The biodegradation and biodetoxification ability of five prominent mycotoxins, namely aflatoxin B1 (AFB1), ochratoxin-A (OTA), zearalenone (ZON), T-2 toxin (T-2) and deoxynivalenol (DON) of Cupriavidus genus were investigated. Biological methods are the most appropriate approach to detoxify mycotoxins. The Cupriavidus genus has resistance to heavy metals and can be found in several niches such as root nodules and aquatic environments. The genus has 17 type strains, 16 of which have been investigated in the present study. According to the results, seven type strains can degrade OTA, four strains can degrade AFB1, four strains can degrade ZON and three strains can degrade T-2. None of the strains can degrade DON. The biodetoxification was measured using different biotests. SOS-chromotest was used for detecting the genotoxicity of AFB1, the BLYES test was used to evaluate the oestrogenicity of ZON, and the zebrafish embryo microinjection test was conducted to observe the teratogenicity of OTA, T-2 and their by-products. Two type strains, namely C. laharis CCUG 53908T and C. oxalaticus JCM 11285T reduced the genotoxicity of AFB1, whilst C. basilensis DSM 11853T decreased the oestrogenic of ZON. There were strains which were able to biodegrade more than two mycotoxins. Two strains degraded two mycotoxins, namely C. metalliduriens CCUG 13724T (AFB1, T-2) and C. oxalaticus (AFB1, ZON) whilst two strains C. pinatubonensis DSM 19553T and C. basilensis degraded three toxins (ZON, OTA, T-2) and C. numazuensis DSM 15562T degraded four mycotoxins (AFB1, ZON, OTA, T-2), which is unique a phenomenon amongst bacteria.


Asunto(s)
Cupriavidus , Micotoxinas , Zearalenona , Aflatoxina B1/toxicidad , Animales , Cupriavidus/genética , Pez Cebra
6.
BMC Genomics ; 19(1): 472, 2018 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-29914355

RESUMEN

BACKGROUND: The availability of the genomes of two archaic humans, Neanderthal and Denisovan, and that of modern humans provides researchers an opportunity to investigate genetic differences between these three subspecies on a genome-wide scale. Here we describe an algorithm that predicts statistically significant motifs based on the difference between a given motif's actual and expected distributions. The algorithm was previously applied to plants but was modified for this work. RESULTS: The result of applying the algorithm to the human, Neanderthal, and Denisovan genomes is a catalog of potential regulatory motifs in these three human subspecies. We examined the distributions of these motifs in genetic elements including human retroviruses, human accelerated regions, and human accelerated conserved noncoding sequences regions. Differences in these distributions could be the origin of differences in phenotype between the three subspecies. Twenty significant motifs common to all three genomes were found; thirty-three were found in endogenous retroviruses in Neanderthal and Denisovan. Ten of these motifs mapped to the 22 bp core of MiR-1304. The core of this genetic element regulates the ENAM and AMTN genes, which take part in odontogenesis and whose 3' UTRs contained significant motifs. The introns of 20 genes were found to contain a large number of significant motifs, which were also overrepresented in 49 human accelerated regions. These genes include NAV2, SorCS2, TRAPPC9, GRID1, PRDM16, CAMTA1, and ASIC which are all involved in neuroregulation. Further analysis of these genes using the GO database indicates that many are associated with neurodevelopment. Also, varying numbers of significant motifs were found to occur in regions of the Neanderthal and Denisovan genomes that are missing from the human genome, suggesting further functional differences between modern and archaic humans. CONCLUSION: Although Neanderthal and Denisovan are now extinct, detailed examination of elements from their genomes can shed light on possible phenotypic and cognitive differences between these two archaic human subspecies and modern humans. Genetic similarities and differences between these three subspecies and other fossil hominids would also be of interest.


Asunto(s)
Fósiles , Genoma , Hombre de Neandertal/genética , Motivos de Nucleótidos/genética , Animales , Retrovirus Endógenos/genética , Humanos , Fenotipo , Regiones Promotoras Genéticas , Transactivadores
7.
Curr Microbiol ; 75(7): 907-917, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29511873

RESUMEN

Aflatoxin B1 (AFB1) and zearalenone (ZON) are dangerous mycotoxins due to their carcinogenicity or oestrogenicity. To alleviate negative effects on humans and animals, successful detoxification tools are needed. The application of microorganisms to biodegrade mycotoxins can be an effective way in food and feed industry enhancing food safety. Several Rhodococcus strains are effective in the degradation of aromatic mycotoxins and their application in mycotoxin biodetoxification processes is a promising field of biotechnology. In this study, we investigated the AFB1 and ZON detoxification ability of 42 type strains of Rhodococcus species. Samples were analysed by high-performance liquid chromatograph equipped with fluorescence detector for mycotoxin concentration and SOS-chromotest was used for monitoring remaining genotoxicity. Out of the 42 Rhodococcus strains, 18 could eliminate more than 90% of the applied AFB1 and the genotoxicity was ceased by 15 strains in 72 h (R. imtechensis JCM 13270T, R. erythropolis JCM 3201T, R. tukisamuensis JCM 11308T, R. rhodnii JCM 3203T, R. aerolatus JCM 19485T, R. enclensis DSM 45688T, R. lactis DSM 45625T, R. trifolii DSM 45580T, R. qingshengii DSM 45222T, R. artemisiae DSM 45380T, R. baikonurensis DSM 44587T, R. globerulus JCM 7472T, R. kroppenstedtii JCM 13011T, R. pyridinivorans JCM 10940T, R. corynebacterioides JCM 3376T). In case of ZON, only R. percolatus JCM 10087T was able to degrade more than 90% of the compound and to reduce the oestrogenicity with 70%.


Asunto(s)
Aflatoxina B1/metabolismo , Rhodococcus/metabolismo , Zearalenona/metabolismo , Biodegradación Ambiental , Rhodococcus/clasificación
8.
Nucleic Acids Res ; 44(10): 4595-609, 2016 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-26823500

RESUMEN

We present a theory of pluralistic and stochastic gene regulation. To bridge the gap between empirical studies and mathematical models, we integrate pre-existing observations with our meta-analyses of the ENCODE ChIP-Seq experiments. Earlier evidence includes fluctuations in levels, location, activity, and binding of transcription factors, variable DNA motifs, and bursts in gene expression. Stochastic regulation is also indicated by frequently subdued effects of knockout mutants of regulators, their evolutionary losses/gains and massive rewiring of regulatory sites. We report wide-spread pluralistic regulation in ≈800 000 tightly co-expressed pairs of diverse human genes. Typically, half of ≈50 observed regulators bind to both genes reproducibly, twice more than in independently expressed gene pairs. We also examine the largest set of co-expressed genes, which code for cytoplasmic ribosomal proteins. Numerous regulatory complexes are highly significant enriched in ribosomal genes compared to highly expressed non-ribosomal genes. We could not find any DNA-associated, strict sense master regulator. Despite major fluctuations in transcription factor binding, our machine learning model accurately predicted transcript levels using binding sites of 20+ regulators. Our pluralistic and stochastic theory is consistent with partially random binding patterns, redundancy, stochastic regulator binding, burst-like expression, degeneracy of binding motifs and massive regulatory rewiring during evolution.


Asunto(s)
Regulación de la Expresión Génica , Modelos Genéticos , Animales , Sitios de Unión , Línea Celular , Inmunoprecipitación de Cromatina , ADN/metabolismo , Genoma Humano , Humanos , Aprendizaje Automático , Ratones , Proteínas Ribosómicas/genética , Procesos Estocásticos
9.
Int J Syst Evol Microbiol ; 66(4): 1627-1632, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26738749

RESUMEN

A Gram-stain-negative, obligately aerobic, non-motile, non-sporulating, rod-shaped bacterium, designated TZCO2T, was isolated from the soil of an irrigated coffee plantation in Arusha, Tanzania, East Africa. Phylogenetic analysis, based on 16S rRNA gene sequences, indicated that the isolate is affiliated with the genus Taibaiella in the family Chitinophagaceae. Its closest relative is Taibaiella koreensis THG-DT86T (96.7%). The pH and temperature ranges for growth were pH 6.0-8.5 (optimum 7.0-7.5) and 10-35 °C (optimum 30 °C, respectively. The predominant fatty acids were iso-C15:0 (32.4%), iso-C15:1 G (22.6%), iso-C17:0 (15.1%) and iso-C17:0 3-OH (10.0%) The only isoprenoid quinone detected in strain TZCO2T was menaquinone-7 (MK-7); the major polar lipids were phosphoaminolipid, phosphatidylethanolamine, unidentified aminolipids and lipids. The DNA G+C content was 51.9 mol%. Physiological and chemotaxonomic data further confirmed that strain TZCO2T is distinct from other members of the genus Taibaiella. Thus, strain TZCO2T is considered to represent a novel species of the genus, for which the name Taibaiella coffeisoli sp. nov. is proposed. The type strain is TZCO2T (=NCAIM B 02601T=CCM 8601T).


Asunto(s)
Bacteroidetes/clasificación , Coffea , Filogenia , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Bacteroidetes/genética , Bacteroidetes/aislamiento & purificación , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Tanzanía , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
Plant Cell ; 24(5): 1860-75, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22634764

RESUMEN

A CO(2)-concentrating mechanism (CCM) is essential for the growth of most eukaryotic algae under ambient (392 ppm) and very low (<100 ppm) CO(2) concentrations. In this study, we used replicated deep mRNA sequencing and regulatory network reconstruction to capture a remarkable scope of changes in gene expression that occurs when Chlamydomonas reinhardtii cells are shifted from high to very low levels of CO(2) (≤100 ppm). CCM induction 30 to 180 min post-CO(2) deprivation coincides with statistically significant changes in the expression of an astonishing 38% (5884) of the 15,501 nonoverlapping C. reinhardtii genes. Of these genes, 1088 genes were induced and 3828 genes were downregulated by a log(2) factor of 2. The latter indicate a global reduction in photosynthesis, protein synthesis, and energy-related biochemical pathways. The magnitude of transcriptional rearrangement and its major patterns are robust as analyzed by three different statistical methods. De novo DNA motif discovery revealed new putative binding sites for Myeloid oncogene family transcription factors potentially involved in activating low CO(2)-induced genes. The (CA)(n) repeat (9 ≤ n ≤ 25) is present in 29% of upregulated genes but almost absent from promoters of downregulated genes. These discoveries open many avenues for new research.


Asunto(s)
Dióxido de Carbono/metabolismo , Chlamydomonas reinhardtii/metabolismo , Chlamydomonas reinhardtii/genética , Datos de Secuencia Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
11.
medRxiv ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38746245

RESUMEN

Background: The incidence and mortality rates of hepatocellular carcinoma (HCC) among Hispanics in the United States are much higher than those of non-Hispanic whites. We conducted comprehensive multi-omics analyses to understand molecular alterations in HCC among Hispanic patients. Methods: Paired tumor and adjacent non-tumor samples were collected from 31 Hispanic HCC in South Texas (STX-Hispanic) for genomic, transcriptomic, proteomic, and metabolomic profiling. Additionally, serum lipids were profiled in 40 Hispanic and non-Hispanic patients with or without clinically diagnosed HCC. Results: Exome sequencing revealed high mutation frequencies of AXIN2 and CTNNB1 in STX Hispanic HCCs, suggesting a predominant activation of the Wnt/ß-catenin pathway. The TERT promoter mutation frequency was also remarkably high in the Hispanic cohort. Cell cycles and liver functions were identified as positively- and negatively-enriched, respectively, with gene set enrichment analysis. Gene sets representing specific liver metabolic pathways were associated with dysregulation of corresponding metabolites. Negative enrichment of liver adipogenesis and lipid metabolism corroborated with a significant reduction in most lipids in the serum samples of HCC patients. Two HCC subtypes from our Hispanic cohort were identified and validated with the TCGA liver cancer cohort. The subtype with better overall survival showed higher activity of immune and angiogenesis signatures, and lower activity of liver function-related gene signatures. It also had higher levels of immune checkpoint and immune exhaustion markers. Conclusions: Our study revealed some specific molecular features of Hispanic HCC and potential biomarkers for therapeutic management of HCC and provides a unique resource for studying Hispanic HCC.

12.
J Bacteriol ; 194(5): 1247-8, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22328750

RESUMEN

Here, we present the complete genome sequence of Rhodococcus pyridinivorans AK37 strain NCAIM PB1376, which was isolated from an oil-polluted site in Hungary. R. pyridinivorans AK37 is an aerobic, nonsporulating, nonmotile, gram-positive bacterium with remarkable aromatic-decomposing activity.


Asunto(s)
ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Rhodococcus/genética , Rhodococcus/aislamiento & purificación , Microbiología del Suelo , Aerobiosis , Hungría , Hidrocarburos Aromáticos/metabolismo , Datos de Secuencia Molecular , Rhodococcus/metabolismo , Rhodococcus/fisiología , Análisis de Secuencia de ADN
13.
J Bacteriol ; 194(8): 2109-10, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22461549

RESUMEN

Here we report on the complete genome sequence of Cupriavidus basilensis OR16 NCAIM BO2487. The genome of strain OR16 contains 7,534 putative coding sequences, including a large set of xenobiotics-degrading genes and a unique glucose dehydrogenase gene that is absent from other Cupriavidus genomes.


Asunto(s)
Cupriavidus/genética , Genoma Bacteriano , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Cupriavidus/clasificación , Regulación Bacteriana de la Expresión Génica/fisiología , Glucosa 1-Deshidrogenasa/genética , Glucosa 1-Deshidrogenasa/metabolismo , Datos de Secuencia Molecular , Especificidad de la Especie
14.
ScientificWorldJournal ; 2012: 657945, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22649303

RESUMEN

We present an experiment done on a bar(+) wheat line treated with 14 different concentrations of glufosinate ammonium-an effective component of nonselective herbicides-during seed germination in a closed experimental system. Yield components as number of spikes per plant, number of grains per spike, thousand kernel weight, and yield per plant were thoroughly analysed and statistically evaluated after harvesting. We found that a concentration of glufosinate ammonium 5000 times the lethal dose was not enough to inhibit the germination of transgenic plants expressing the bar gene. Extremely high concentrations of glufosinate ammonium caused a bushy phenotype, significantly lower numbers of grains per spike, and thousand kernel weights. Concerning the productivity, we observed that concentrations of glufosinate ammonium 64 times the lethal dose did not lead to yield depression. Our results draw attention to the possibilities implied in the transgenic approaches.


Asunto(s)
Acetiltransferasas/genética , Aminobutiratos/administración & dosificación , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/efectos de los fármacos , Triticum/efectos de los fármacos , Resistencia a Medicamentos/genética , Herbicidas/farmacología , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Triticum/genética , Triticum/crecimiento & desarrollo
15.
Artículo en Inglés | MEDLINE | ID: mdl-35394401

RESUMEN

Wheat straw is commonly used as a cellulose source in mushroom compost and could be a secondary source of mycotoxin contamination in the food chain. We cultivated edible Agaricus bisporus and Pleurotus ostreatus on T-2/HT-2 artificially-contaminated mushroom compost and developed and in-house validated an UHPLC-MS/MS method for determination of T-2, HT-2, T2-triol and T2-tetraol in mushroom compost and mushroom basidiocarp. A rapid phase I metabolization of T-2 and HT-2 in mushroom compost was observed. In Agaricus bisporus, basidiocarps 8-15 µg kg-1 accumulation of HT-2 calculated on wet weight was measured. No detectable mycotoxins were found in Pleurotus ostreatus basidiocarp.


Asunto(s)
Agaricus , Compostaje , Micotoxinas , Toxina T-2/análogos & derivados , Espectrometría de Masas en Tándem
16.
Plant Mol Biol ; 75(4-5): 399-412, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21246257

RESUMEN

The accumulation of toxic compounds generated by the interaction between reactive oxygen species and polyunsaturated fatty acids of membrane lipids can significantly damage plant cells. A plethora of enzymes act on these reactive carbonyls, reducing their toxicity. Based on the chromosomal localization and on their homology with other stress-induced aldo-keto reductases (AKRs) we have selected three rice AKR genes. The transcription level of OsAKR1 was greatly induced by abscisic acid and various stress treatments; the other two AKR genes tested were moderately stress-inducible. The OsAKR1 recombinant protein exhibited a high nicotinamide adenine dinucleotide phosphate-dependent catalytic activity to reduce toxic aldehydes including glycolysis-derived methylglyoxal (MG) and lipid peroxidation-originated malondialdehyde (MDA). The function of this enzyme in MG detoxification was demonstrated in vivo in E. coli and in transgenic plants overproducing the OsAKR1 protein. Heterologous synthesis of the OsAKR1 enzyme in transgenic tobacco plants resulted in increased tolerance against oxidative stress generated by methylviologen (MV) and improved resistance to high temperature. In these plants lower levels of MDA were detected both following MV and heat treatment due to the activity of the OsAKR1 enzyme. The transgenic tobaccos also exhibited higher AKR activity and accumulated less MG in their leaves than the wild type plants; both in the presence and absence of heat stress. These results support the positive role of OsAKR1 in abiotic stress-related reactive aldehyde detoxification pathways and its use for improvement of stress tolerance in plants.


Asunto(s)
Oxidorreductasas de Alcohol/biosíntesis , Oryza/fisiología , Aclimatación/genética , Aclimatación/fisiología , Oxidorreductasas de Alcohol/genética , Aldehído Reductasa , Aldo-Ceto Reductasas , Escherichia coli/genética , Escherichia coli/metabolismo , Genes de Plantas , Calor , Malondialdehído/metabolismo , Lípidos de la Membrana/metabolismo , Oryza/genética , Estrés Oxidativo , Filogenia , Plantas Modificadas Genéticamente , Piruvaldehído/metabolismo , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Nicotiana/genética , Nicotiana/fisiología
17.
Mol Genet Genomics ; 285(5): 375-91, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21437642

RESUMEN

Plants undergo an extensive change in gene regulation during abiotic stress. It is of great agricultural importance to know which genes are affected during stress response. The genome sequence of a number of plant species has been determined, among them Arabidopsis and Oryza sativa, whose genome has been annotated most completely as of yet, and are well-known organisms widely used as experimental systems. This paper applies a statistical algorithm for predicting new stress-induced motifs and genes by analyzing promoter sets co-regulated by abiotic stress in the previously mentioned two species. After identifying characteristic putative regulatory motif sequence pairs (dyads) in the promoters of 125 stress-regulated Arabidopsis genes and 87 O. sativa genes, these dyads were used to screen the entire Arabidopsis and O. sativa promoteromes to find related stress-induced genes whose promoters contained a large number of these dyads found by our algorithm. We were able to predict a number of putative dyads, characteristic of a large number of stress-regulated genes, some of them newly discovered by our algorithm and serve as putative transcription factor binding sites. Our new motif prediction algorithm comes complete with a stand-alone program. This algorithm may be used in motif discovery in the future in other species. The more than 1,200 Arabidopsis and 1,700 Orzya sativa genes found by our algorithm are good candidates for further experimental studies in abiotic stress.


Asunto(s)
Algoritmos , Arabidopsis/genética , Oryza/genética , Arabidopsis/fisiología , Secuencia de Bases , Oryza/fisiología , Regiones Promotoras Genéticas , Estrés Fisiológico , Levaduras/genética
18.
Mutat Res ; 726(1): 1-7, 2011 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-21871580

RESUMEN

To monitor cytotoxic and genotoxic effects of aflatoxin, a luminescent assay employing Aliivibrio fischeri as a test organism and a colorimetric assay based on the SOS-Chromotest were adapted to our needs. The aim of this method-developing work was to be able to select - from a collection of environmental isolates - microbes that degrade aflatoxin without production of harmful intermediates and by-products, in a fast and cost-effective way. By the combination of the two modified assays, microbes that met these criteria have been successfully selected. Among thirty-three isolates, the strain Rhodococcus rhodochrous NI2 proved to be the best aflatoxin-B1-degrading microbe, with the weakest harmful biological effects throughout aflatoxin-B1-degradation. Our findings underline the necessity to employ bio-tests in biodegradation assays, as cytotoxicity and/or genotoxicity may occur even after substantial degradation of the toxins.


Asunto(s)
Aflatoxina B1/metabolismo , Biodegradación Ambiental , Aliivibrio/metabolismo , Pruebas de Mutagenicidad/métodos , Rhodococcus/metabolismo , Pruebas de Toxicidad/métodos
19.
J Hazard Mater ; 416: 125788, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-33838512

RESUMEN

Aflatoxin B1-contaminated feeds and foods induce various health problems in domesticated animals and humans, including tumor development and hepatotoxicity. Aflatoxin B1 also has embryotoxic effects in different livestock species and humans. However, it is difficult to distinguish between the indirect, maternally-mediated toxic effects and the direct embryotoxicity of aflatoxin B1 in mammals. In the present study, we investigated the aflatoxin B1-induced direct embryotoxic effects in a zebrafish embryo model system combining toxicological, transcriptomic, immunological, and biochemical approaches. Embryonic exposure to aflatoxin B1 induced significant changes at the transcriptome level resulting in elevated expression of inflammatory gene network and repression of lipid metabolism and gastrointestinal tract development-related gene sets. According to the gene expression changes, massive neutrophil granulocyte influx, elevated nitric oxide production, and yolk lipid accumulation were observed in the abdominal region of aflatoxin B1-exposed larvae. In parallel, aflatoxin B1-induced defective gastrointestinal tract development and reduced L-arginine level were found in our model system. Our results revealed the complex direct embryotoxic effects of aflatoxin B1, including inhibited lipid utilization, defective intestinal development, and inflammation.


Asunto(s)
Aflatoxina B1 , Pez Cebra , Aflatoxina B1/toxicidad , Animales , Tracto Gastrointestinal , Humanos , Inflamación/inducido químicamente , Inflamación/genética , Movilización Lipídica , Transcriptoma , Pez Cebra/genética
20.
Toxins (Basel) ; 12(7)2020 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-32708466

RESUMEN

T-2 mycotoxin degradation and detoxification efficiency of seven bacterial strains were investigated with zebrafish microinjection method in three steps ((1) determination of mycotoxin toxicity baseline, (2) examination of bacterial metabolites toxicity, (3) identification of degradation products toxicity). Toxicity of T-2 was used as a baseline of toxic effects, bacterial metabolites of strains as control of bacterial toxicity and degradation products of toxin as control of biodegradation were injected into one-cell stage embryos in the same experiment. The results of in vivo tests were checked and supplemented with UHPLC-MS/MS measurement of T-2 concentration of samples. Results showed that the Rhodococcus erythropolis NI1 strain was the only one of the seven tested (R. gordoniae AK38, R. ruber N361, R. coprophilus N774, R. rhodochrous NI2, R. globerulus N58, Gordonia paraffinivorans NZS14), which was appropriated to criteria all aspects (bacterial and degradation metabolites of strains caused lower toxicity effects than T-2, and strains were able to degrade T-2 mycotoxin). Bacterial and degradation metabolites of the NI1 strain caused slight lethal and sublethal effects on zebrafish embryos at 72- and 120-h postinjection. Results demonstrated that the three-step zebrafish microinjection method is well-suited to the determination and classification of different bacterial strains by their mycotoxin degradation and detoxification efficiency.


Asunto(s)
Rhodococcus/metabolismo , Toxina T-2/metabolismo , Toxina T-2/toxicidad , Pez Cebra/embriología , Alimentación Animal/microbiología , Animales , Bioensayo , Cromatografía Líquida de Alta Presión , Embrión no Mamífero/efectos de los fármacos , Cadena Alimentaria , Microbiología de Alimentos , Inactivación Metabólica , Microinyecciones , Espectrometría de Masas en Tándem
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