RESUMO
In light of the post-genomic era, epigenetics brings about an opportunity to better understand how the molecular machinery works and is led by a complex dynamic set of mechanisms, often intricate and complementary in many aspects. In particular, epigenetics links developmental biology and genetics, as well as many other areas of knowledge. The present work highlights substantial scopes and relevant discoveries related to the development of the term from its first notions. To our understanding, the concept of epigenetics needs to be revisited, as it is one of the most relevant and multifaceted terms in human knowledge. To redirect future novel experimental or theoretical efforts, it is crucial to compile all significant issues that could impact human and ecological benefit in the most precise and accurate manner. In this paper, the reader can find one of the widest compilations of the landmarks and epistemic considerations of the knowledge of epigenetics across the history of biology from the earliest epigenetic formulation to genetic determinism until the present. In the present work, we link the current body of knowledge and earlier pre-genomic concepts in order to propose a new definition of epigenetics that is faithful to its regulatory nature.
Assuntos
Epigênese Genética , Epigenômica , Humanos , Epigenômica/métodos , Animais , Metilação de DNARESUMO
The problem of phosphorus and nitrogen deficiency in agricultural soils has been solved by adding chemical fertilizers. However, their excessive use and their accumulation have only contributed to environmental contamination. Given the high content of nutrients in biosolids collected from a food industry waste treatment plant, their use as fertilizers was investigated in Zea mays plants grown in sandy loam soil collected from a semi-desert area. These biosolids contained insoluble phosphorus sources; therefore, given the ability of Azotobacter nigricans to solubilize phosphates, this strain was incorporated into the study. In vitro, the suitable conditions for the growth of Z. mays plants were determined by using biosolids as a fertilizer and A. nigricans as a plant-growth-promoting microorganism; in vitro, the ability of A. nigricans to solubilize phosphates, fix nitrogen, and produce indole acetic acid, a phytohormone that promotes root formation, was also evaluated. At the greenhouse stage, the Z. mays plants fertilized with biosolids at concentrations of 15 and 20% (v/w) and inoculated with A. nigricans favored the development of bending strength plants, which was observed on the increased stem diameter (>13.5% compared with the negative control and >7.4% compared with the positive control), as well as a better absorption of phosphorus and nitrogen, the concentration of which increased up to 62.8% when compared with that in the control treatments. The interactions between plants and A. nigricans were observed via scanning electron microscopy. The application of biosolids and A. nigricans in Z. mays plants grown in greenhouses presented better development than when Z. mays plants were treated with a chemical fertilizer. The enhanced plant growth was attributed to the increase in root surface area.
RESUMO
Dendroctonus bark beetles are the most destructive agents in coniferous forests. These beetles come into contact with the toxic compounds of their host's chemical defenses throughout their life cycle, some of which are also used by the insects as kairomones to select their host trees during the colonization process. However, little is known about the molecular mechanisms by which the insects counteract the toxicity of these compounds. Here, two sibling species of bark beetles, D. valens and D. rhizophagus, were stimulated with vapors of a blend of their main kairomones (α-pinene, ß-pinene and 3-carene), in order to compare the transcriptional response of their gut. A total of 48 180 unigenes were identified in D. valens and 43 704 in D. rhizophagus, in response to kairomones blend. The analysis of differential gene expression showed a transcriptional response in D. valens (739 unigenes, 0.58-10.36 Log2FC) related to digestive process and in D. rhizophagus (322 unigenes 0.87-13.08 Log2FC) related to xenobiotics metabolism. The expression profiles of detoxification genes mainly evidenced the up-regulation of COEs and GSTs in D. valens, and the up-regulation of P450s in D. rhizophagus. Results suggest that terpenes metabolism comes accompanied by an integral hormetic response, result of compensatory mechanisms, including the activation of other metabolic pathways, to ensure the supply of energy and the survival of organisms which is specific for each species, according to its life history and ecological strategy.
RESUMO
Every year, more than 500,000 new cases of cervical cancer are reported, making it the fourth leading cause of cancer globally. Although human papillomavirus (HPV) vaccines show promise as a protective measure, HPV-related cancers remain a public health problem since the vaccines, which are only specific to certain viral types, are unavailable for mass distribution. Furthermore, the effects of toxicity following ionizing radiation therapy have reoriented views toward the search for radiosensitizers that can reduce toxicity as a consequence of decreased radiation doses. Here, we isolated ergosterol peroxide (EP) from Pleurotus ostreatus and purified it to test its potential effects in vitro. We thus observed that a gradual increase in EP dose correlates with a loss of viability in HeLa and CaSki cervical cell lines. Dose/response curves were constructed using cervical cancer cell lines, as well as normal human peripheral blood mononuclear cells. The selectivity of EP in human lymphocytes and cervical cancer cell lines was tested, and no toxicity was found in normal cells. A combination of treatments revealed a radiosensitizer effect in HeLa cells, when measuring the exposure to EP followed by irradiation with 137Cs. Our findings suggest that EP may be effective as a radiosensitizer in treating cervical cancer.
Assuntos
Ergosterol/análogos & derivados , Extratos Vegetais/farmacologia , Pleurotus/química , Radiossensibilizantes/farmacologia , Neoplasias do Colo do Útero/radioterapia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Ergosterol/farmacologia , Feminino , Humanos , Tolerância a Radiação , Neoplasias do Colo do Útero/fisiopatologiaRESUMO
Dendroctonus bark beetles (Scolytinae) are one of the most important disturbance agents of coniferous forests in North and Central America. These beetles spend their lives almost entirely under the tree bark, and their survival and reproductive success depend on their ability to overcome the toxic effect of the trees' oleoresin. The cytochromes P450 (CYPs) are associated with the detoxification process of xenobiotics, as well as other physiological processes. Different cytochromes (families 4, 6, and 9) in the Dendroctonus species have been expressed under several experimental conditions; nevertheless, the expression time-course of these genes is unknown. To explore the induction speed of CYPs, we evaluated the relative expression of the CYP6BW5, CYP6DG1, CYP6DJ2, CYP9Z18, and CYP9Z20 genes at the early hours of drilling and settling into a tree (1, 2, 4, 6, 8, 12, 18 h) both in females and males, solitary or paired, of the bark beetle Dendroctonus rhizophagus Thomas and Bright. Our findings show that the five genes were rapidly overexpressed in the early hours (1 to 6 h) in both sexes and in solitary and paired conditions, suggesting their participation in the detoxification process. Additionally, the CYPs expression shows up- and down-regulation patterns through these short times, suggesting their probable participation in other physiological processes as the biosynthesis of hormones, pheromones or compounds related to reproduction.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Gorgulhos/enzimologia , Animais , Sistema Enzimático do Citocromo P-450/genética , Comportamento Alimentar , Feminino , Masculino , Árvores , Gorgulhos/genéticaRESUMO
Although the Atoyac River has been classified as highly polluted by environmental authorities, several communities are settled on its banks, affecting around 1.5 million persons, as well as farmland, due to an environmental distribution of toxics in the area. Our aim was to demonstrate that this environment affects important physiological processes that have an impact in health, so we conducted a study of schoolchildren from small communities on the banks of the river and in another similar town located far from it. 91 and 93 students, boys and girls, were studied from each site for oxidative stress index (OSI), calculated from the total antioxidant capacity and the total oxidative status, BTEX metabolite excretion and relevant metabolic polymorphisms participating in the bioactivation-detoxification of most VOC: CYP2E1 RsaI, NQO1 C609T, and null polymorphisms of GSTT1 and GSTM1. Results showed that OSI was significantly higher in children living by the river (5.23 ± 3.4 vs 2.59 ± 1.46, 95% C.I.). At this site, OSI was correlated with diminished metabolite excretion and a diminished antioxidant capacity; an association with genotypes CYP2E1RsaI (c2c2), GSTT1 present and NQO1*2 (CC) was also observed. Furthermore, boys at this site exhibited a diminished BMI compared to boys from the other community who were younger. IN CONCLUSION: children living at polluted sites like this, show early biological effects that might lead to health problems in their adult life. Environmental protection should be enforced to protect people's health in these sites where not even environmental monitoring is done. Environ. Mol. Mutagen. 59:639-652, 2018. © 2018 Wiley Periodicals, Inc.
Assuntos
Exposição Ambiental/efeitos adversos , Resíduos Industriais/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/urina , Poluentes da Água/metabolismo , Poluentes da Água/urina , Adolescente , Criança , Feminino , Genótipo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Humanos , Inativação Metabólica , Resíduos Industriais/análise , Masculino , México , Polimorfismo Genético , Rios/química , Compostos Orgânicos Voláteis/efeitos adversos , Compostos Orgânicos Voláteis/análise , Poluentes da Água/efeitos adversos , Poluentes da Água/análiseRESUMO
Aquatic hypoxia is a seasonal condition in some coastal and continental wetlands where co-exposure with polycyclic aromatic hydrocarbons (PAHs) pollution may be detrimental to the biota. In the present study, adult tilapia, an euryoxic fish of high economic importance, were intraperitoneally injected with benzo[a]pyrene (BaP) (20 mg kg(-1)) and then exposed to graded hypoxia to assess combined effects on some detoxification and fitness parameters. Seventy-two hours after a stepped decrease in dissolved oxygen (<2 mg L(-1)), BaP treatment resulted in a significant diminution on the biliary BaP concentration (70% of normoxic group) and an increase in blood glucose levels (2.17-fold compared with normoxic group). These effects returned to control values in the following 48 h of hypoxia exposure. BaP-induced CYP1A mRNA levels were unaffected by hypoxia, suggesting that reduced bile BaP concentration may be related with effects on protein amount or enzyme activities. LDH mRNA levels, blood lactate and hematocrit remained without change, suggesting no extreme detrimental effects for tilapia in the short-term of the BaP-hypoxia challenge. Our results indicate that BaP treatment and hypoxia targeted glucose metabolism and biliary BaP elimination, probably by favoring the storage of BaP in tilapia tissues.
Assuntos
Benzo(a)pireno/toxicidade , Bile/química , Citocromo P-450 CYP1A1/metabolismo , Fígado/efeitos dos fármacos , Tilápia/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Benzo(a)pireno/química , Glicemia/análise , Citocromo P-450 CYP1A1/genética , Hematócrito , Hipóxia , L-Lactato Desidrogenase/genética , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/sangue , Fígado/metabolismo , RNA Mensageiro/metabolismo , Fatores de Tempo , Poluentes Químicos da Água/químicaRESUMO
OBJECTIVE: This study evaluates the effects of exposure to pesticides on the health of pesticide retailers. METHODS: The study population comprised 83-male pesticide retailers and 98 controls. Serum butyrylcholinesterase levels and complete blood analysis were performed in a certified laboratory and each subject completed a structured questionnaire. RESULTS: Butyrylcholinesterase activity and hematological parameters such as hemoglobin and hematocrit were significantly lower in pesticide retailers than in control subjects. In contrast, platelet count as well as hepatic parameters such as glutamic-pyruvate transaminase and gamma-glutamyl transpeptidase activities was higher in pesticide retailers. Furthermore, pesticide retailers experienced burning sensations in the skin more frequently than controls. CONCLUSIONS: These preliminary results suggest the importance of evaluating further toxicological biomarkers in these populations.
Assuntos
Butirilcolinesterase/sangue , Praguicidas/intoxicação , gama-Glutamiltransferase/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Estudos Transversais , Índices de Eritrócitos , Humanos , Testes de Função Hepática , Masculino , Exposição Ocupacional , Praguicidas/sangue , Autorrelato , Inquéritos e QuestionáriosRESUMO
Together with industrial development in Mexico has come a major increase in the generation of air pollutants. Some of these pollutants include compounds such as ozone, that like tobacco smoke, are related to the severity of certain respiratory diseases such as asthma. Although asthma affects people of all ages, it has been shown to primarily affect children and adolescents. Certain genetic polymorphisms have been found to be related to the symptoms or severity of the disease. The use of biomarker candidates has been proposed to study such genetic variations in several populations to detect and control this illness in its early stages. In addition, new research topics have been suggested that suggest a role for the metabolism of xenobiotics in the development of asthma. Furthermore, analysis of these polymorphisms in a Mexican population of children is being used as the first step in the development of strategies for detecting vulnerable groups. This paper reviews some genetic polymorphisms associated with allergic responses and their relationship with toxic exposure.
Assuntos
Poluentes Atmosféricos/efeitos adversos , Asma/induzido quimicamente , Asma/genética , Polimorfismo Genético , Xenobióticos/efeitos adversos , Adolescente , Criança , Citocinas/biossíntese , Citocinas/genética , HumanosRESUMO
We determined the hepatic Cytochrome P4501A (CYP1A) mRNA and Ethoxyresorufin-O-deethylase (EROD) activities in the fish, Ariopsis felis, from highly polluted to relatively pristine regions in the southwest Gulf of Mexico and their relationship with the genetic polymorphisms of the same fish. We hypothesized that a high genetic variation reflects interindividual variability in levels of CYP1A mRNA underlying the pathway culminating in EROD induction caused by the environmental contaminants. Catfish from Laguna de Mecoacan exhibited marked induction of CYP1A mRNA and high levels of hepatic EROD activities, whereas fish from Laguna de Celestun showed no induction of CYP1A mRNA and moderately low levels of EROD activities. In contrast, the similarity index considering all samples varied from 0.4 to 0.87, showing a wide range of variation. A dendrogram showed a clear grouping of fish collected from the Laguna de Terminos, Rio Coatzacoalcos and Laguna de Celestun, with discrete subgroups according to region. In contrast, fish from Laguna de Mecoacan were grouped together completely separate from the rest of the fish. Despite the low number of fish from Mecoacan (a high bootstrap support was observed in this group), the results indicated a significant genetic variability in comparison with the other ecosystems included. The differential level of expression of CYP1A and the EROD activity observed among the ecosystems analyzed could be due to the high range of genetic variation, with special emphasis on fish collected in Mecoacan where it is possible to find a subspecies of Ariopsis felis.