RESUMO
The novel ß-coronavirus, SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19), has infected more than 177 million people and resulted in 3.84 million death worldwide. Recent epidemiological studies suggested that some environmental factors, such as air pollution, might be the important contributors to the mortality of COVID-19. However, how environmental exposure enhances the severity of COVID-19 remains to be fully understood. In the present report, we provided evidence showing that mdig, a previously reported environmentally-induced oncogene that antagonizes repressive trimethylation of histone proteins, is an important regulator for SARS-CoV-2 receptors neuropilin-1 (NRP1) and NRP2, cathepsins, glycan metabolism and inflammation, key determinants for viral infection and cytokine storm of the patients. Depletion of mdig in bronchial epithelial cells by CRISPR-Cas-9 gene editing resulted in a decreased expression of NRP1, NRP2, cathepsins, and genes involved in protein glycosylation and inflammation, largely due to a substantial enrichment of lysine 9 and/or lysine 27 trimethylation of histone H3 (H3K9me3/H3K27me3) on these genes as determined by ChIP-seq. Meanwhile, we also validated that environmental factor arsenic is able to induce mdig, NRP1 and NRP2, and genetic disruption of mdig lowered expression of NRP1 and NRP2. Furthermore, mdig may coordinate with the Neanderthal variants linked to an elevated mortality of COVID-19. These data, thus, suggest that mdig is a key mediator for the severity of COVID-19 in response to environmental exposure and targeting mdig may be the one of the effective strategies in ameliorating the symptom and reducing the mortality of COVID-19.
Assuntos
COVID-19/metabolismo , COVID-19/virologia , Dioxigenases/metabolismo , Histona Desmetilases/metabolismo , Neuropilina-1/metabolismo , Proteínas Nucleares/metabolismo , Polissacarídeos/metabolismo , SARS-CoV-2/metabolismo , Células Epiteliais Alveolares/metabolismo , Animais , COVID-19/epidemiologia , Catepsinas/metabolismo , Linhagem Celular , Células Cultivadas , Dioxigenases/biossíntese , Dioxigenases/genética , Exposição Ambiental , Histona Desmetilases/biossíntese , Histona Desmetilases/genética , Histonas/metabolismo , Humanos , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Pandemias , Ratos , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
Strigolactones (SLs) regulate plant shoot development by inhibiting axillary bud growth and branching. However, the role of SLs in wintersweet (Chimonanthus praecox) shoot branching remains unknown. Here, we identified and isolated two wintersweet genes, CCD7 and CCD8, involved in the SL biosynthetic pathway. Quantitative real-time PCR revealed that CpCCD7 and CpCCD8 were down-regulated in wintersweet during branching. When new shoots were formed, expression levels of CpCCD7 and CpCCD8 were almost the same as the control (un-decapitation). CpCCD7 was expressed in all tissues, with the highest expression in shoot tips and roots, while CpCCD8 showed the highest expression in roots. Both CpCCD7 and CpCCD8 localized to chloroplasts in Arabidopsis. CpCCD7 and CpCCD8 overexpression restored the phenotypes of branching mutant max3-9 and max4-1, respectively. CpCCD7 overexpression reduced the rosette branch number, whereas CpCCD8 overexpression lines showed no phenotypic differences compared with wild-type plants. Additionally, the expression of AtBRC1 was significantly up-regulated in transgenic lines, indicating that two CpCCD genes functioned similarly to the homologous genes of the Arabidopsis. Overall, our study demonstrates that CpCCD7 and CpCCD8 exhibit conserved functions in the CCD pathway, which controls shoot development in wintersweet. This research provides a molecular and theoretical basis for further understanding branch development in wintersweet.
Assuntos
Arabidopsis , Calycanthaceae/genética , Dioxigenases , Genes de Plantas , Proteínas de Plantas , Raízes de Plantas , Plantas Geneticamente Modificadas , Arabidopsis/enzimologia , Arabidopsis/genética , Calycanthaceae/enzimologia , Dioxigenases/biossíntese , Dioxigenases/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genéticaRESUMO
Brain microvascular endothelial cells (BMECs) injury is one of the main causes of cerebrovascular diseases. Circular RNA (circRNA) has been found to be involved in the regulation of cerebrovascular diseases progression. However, the role and mechanism of circ_0003423 in cerebrovascular diseases is still unclear. In our study, oxidized low density lipoprotein (ox-LDL)-induced HBMEC-IM cells were used to construct cerebrovascular cell injury model in vitro. Quantitative real-time PCR was used to determine the expression levels of circ_0003423, miR-589-5p and Ten-eleven translocation 2 (TET2). The interactions between miR-589-5p and circ_0003423 or TET2 were confirmed by dual-luciferase reporter assay, RIP assay and RNA pull-down assay. Cell viability, angiogenesis and apoptosis were measured using cell counting kit 8 assay, tube formation assay and flow cytometry. Cell oxidative stress was evaluated by detecting the levels of reactive oxygen species and lactate dehydrogenase. The protein levels were examined by western blot analysis. Our results showed that circ_0003423 was a downregulated circRNA in ox-LDL-induced HBMEC-IM cells. In the terms of mechanism, circ_0003423 was found to be a sponge of miR-589-5p. Function analysis showed that circ_0003423 overexpression could relieve ox-LDL-induced HBMEC-IM cell injury, and this effect could be reversed by miR-589-5p mimic. In addition, TET2 was confirmed to be a target of miR-589-5p, and its overexpression could alleviate ox-LDL-induced HBMEC-IM cell injury. Moreover, the rescue experiments also confirmed that TET2 silencing could abolish the inhibition effect of anti-miR-589-5p on ox-LDL-induced HBMEC-IM cell injury. In summary, our data showed that circ_0003423 alleviated ox-LDL-induced HBMEC-IM cells injury through regulating the miR-589-5p/TET2 axis.
Assuntos
Encéfalo/metabolismo , Proteínas de Ligação a DNA/biossíntese , Dioxigenases/biossíntese , Lipoproteínas LDL/toxicidade , MicroRNAs/biossíntese , Microvasos/metabolismo , RNA Circular/biossíntese , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Microvasos/efeitos dos fármacosRESUMO
Accumulation of bisretinoids such as A2E and its isomer iso-A2E is thought to mediate blue light-induced oxidative damage associated with age-related macular degeneration (AMD) and autosomal recessive Stargardt disease (STGD1). We hypothesize that increasing dietary intake of the macular carotenoids lutein and zeaxanthin in individuals at risk of AMD and STGD1 can inhibit the formation of bisretinoids A2E and iso-A2E, which can potentially ameliorate macular degenerative diseases. To study the beneficial effect of macular carotenoids in a retinal degenerative diseases model, we used ATP-binding cassette, sub-family A member 4 (Abca4-/-)/ß,ß-carotene-9',10'-oxygenase 2 (Bco2-/-) double knockout (KO) mice that accumulate elevated levels of A2E and iso-A2E in the retinal pigment epithelium (RPE) and macular carotenoids in the retina. Abca4-/-/Bco2-/- and Abca4-/- mice were fed a lutein-supplemented chow, zeaxanthin-supplemented chow or placebo chow (~2.6 mg of carotenoid/mouse/day) for three months. Visual function and electroretinography (ERG) were measured after one month and three months of carotenoid supplementation. The lutein and zeaxanthin supplemented Abca4-/-/Bco2-/- mice had significantly lower levels of RPE/choroid A2E and iso-A2E compared to control mice fed with placebo chow and improved visual performance. Carotenoid supplementation in Abca4-/- mice minimally raised retinal carotenoid levels and did not show much difference in bisretinoid levels or visual function compared to the control diet group. There was a statistically significant inverse correlation between carotenoid levels in the retina and A2E and iso-A2E levels in the RPE/choroid. Supplementation with retinal carotenoids, especially zeaxanthin, effectively inhibits bisretinoid formation in a mouse model of STGD1 genetically enhanced to accumulate carotenoids in the retina. These results provide further impetus to pursue oral carotenoids as therapeutic interventions for STGD1 and AMD.
Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Dioxigenases/genética , Regulação da Expressão Gênica , Luteína/farmacocinética , Degeneração Macular/tratamento farmacológico , Epitélio Pigmentado da Retina/efeitos dos fármacos , Zeaxantinas/farmacocinética , Transportadores de Cassetes de Ligação de ATP/biossíntese , Animais , Dioxigenases/biossíntese , Modelos Animais de Doenças , Eletrorretinografia , Degeneração Macular/metabolismo , Degeneração Macular/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Epitélio Pigmentado da Retina/metabolismo , Visão Ocular/efeitos dos fármacosRESUMO
NADH-dependent reductase enzyme catalyzes the phenolic aldehyde conversion and correspondingly improves the ethanol fermentability of the ethanologenic Zymomonas mobilis. This study constructed the transcriptional landscape of mono/dioxygenase genes in Z. mobilis ZM4 under the stress of the toxic phenolic aldehyde inhibitors of 4-hydroxybenzaldehyde, syringaldehyde, and vanillin. One specific dioxygenase encoding gene ZMO1721 was differentially expressed by 3.07-folds under the stress of 4-hydroxybenzaldehyde among the eleven mono/dioxygenase genes. The purified ZMO1721 shared 99.9% confidence and 48.0% identity with the oxidoreductase in Rhodoferax ferrireducens T118 was assayed and the NADH-dependent reduction activity was confirmed for phenolic aldehyde vanillin conversion. The ZMO1721 gene was then overexpressed in Z. mobilis ZM4 and the 4-hydroxybenzaldehyde conversion rate was accelerated. The cell growth, glucose consumption, and ethanol productivity of Z. mobilis ZM4 were also improved by ZMO1721 overexpression. The genes identified on improving phenolic aldehyde tolerance and ethanol fermentability in this study could be used as the synthetic biology tools for modification of ethanologenic strains.
Assuntos
Aldeídos/metabolismo , Proteínas de Bactérias , Dioxigenases , Etanol/metabolismo , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Zymomonas , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Dioxigenases/biossíntese , Dioxigenases/genética , Zymomonas/enzimologia , Zymomonas/genéticaRESUMO
XanA is an FeII- and α-ketoglutarate-dependent enzyme responsible for the conversion of xanthine to uric acid. It is unique to fungi and it was first described in Aspergillus nidulans. In this work, we present the preliminary characterization of the XanA enzyme from Aspergillus oryzae, a relevant fungus in food production in Japan. The XanA protein (GenBank BAE56701.1) was expressed as a recombinant protein in Escherichia coli BL21 (DE3) Arctic cells. Initial purification assays showed low protein solubility; therefore, the buffer composition was optimized using a fluorescence-based thermal shift assay. The protein was stabilized in solution in the presence of either 600 µM xanthine, 1 M NaCl, 600 µM α-ketoglutarate or 20% glycerol, which increases the melting temperature (Tm) by 2, 4, 5 and 6 °C respectively. The XanA protein was purified by following a three-step purification protocol. The nickel affinity purified protein was subjected to ion-exchange chromatography once the N-terminal 6XHis-tag had been successfully removed, followed by size-exclusion purification. Dynamic light scattering experiments showed that the purified protein was monodisperse and behaved as a monomer in solution. Preliminary activity assays in the presence of xanthine, α-ketoglutarate, and iron suggest that the enzyme is an iron- and α-ketoglutarate-dependent xanthine dioxygenase. Furthermore, the enzyme's optimum activity conditions were determined to be 25 °C, pH of 7.2, HEPES buffer, and 1% of glycerol. In conclusion, we established the conditions to purify the XanA enzyme from A. oryzae in its active form from E. coli bacteria and determined the optimal activity conditions.
Assuntos
Aspergillus oryzae , Dioxigenases , Proteínas Fúngicas , Aspergillus oryzae/enzimologia , Aspergillus oryzae/genética , Dioxigenases/biossíntese , Dioxigenases/química , Dioxigenases/genética , Dioxigenases/isolamento & purificação , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/isolamento & purificação , Ferro/química , Ferro/metabolismo , Ácidos Cetoglutáricos/química , Ácidos Cetoglutáricos/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
TET1 mediates demethylation in tumors, but its role in diabetic nephropathy (DN), a prevalent diabetic complication, is unclear. We attempted to probe the possible mechanism of TET1 in DN. A DN rat model was established and verified by marker detection and histopathological observation. The in vitro model was established on human mesangial cells (HMCs) induced by high glucose (HG), and verified by evaluation of fibrosis and inflammation. The differentially expressed mRNA was screened out by microarray analysis. The most differentially expressed mRNA (TET1) was reduced in DN rats and HG-HMCs. The upstream and downstream factors of TET1 were verified, and their roles in DN were analyzed by gain- and loss-function assays. TET1 was decreased in DN rats and HG-HMCs. High expression of TET1 decreased biochemical indexes and renal injury of DN rats and hampered the activity, fibrosis, and inflammation of HG-HMCs. Ap1 lowered TET1 expression, and enhanced inflammation in HG-HMCs, and accentuated renal injury in DN rats. TET1 overexpression inhibited the effect of Ap1 on DN. TET1 promoted the transcription of Nrf2. The Ap1/TET1 axis mediated the Nrf2/ARE pathway activity. Overall, TET1 overexpression weakened the inhibitory effect of Ap1 on the Nrf2/ARE pathway, thus alleviating inflammation and renal injury in DN.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/metabolismo , Dioxigenases/biossíntese , Fator 2 Relacionado a NF-E2/biossíntese , Transdução de Sinais/fisiologia , Fator de Transcrição AP-1/biossíntese , Animais , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Nefropatias Diabéticas/induzido quimicamente , Nefropatias Diabéticas/patologia , Dioxigenases/antagonistas & inibidores , Humanos , Masculino , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Ratos , Ratos Sprague-DawleyRESUMO
Potato (Solanum tuberosum), a worldwide major food crop, produces the toxic, bitter tasting solanidane glycoalkaloids α-solanine and α-chaconine. Controlling levels of glycoalkaloids is an important focus on potato breeding. Tomato (Solanum lycopersicum) contains a bitter spirosolane glycoalkaloid, α-tomatine. These glycoalkaloids are biosynthesized from cholesterol via a partly common pathway, although the mechanisms giving rise to the structural differences between solanidane and spirosolane remained elusive. Here we identify a 2-oxoglutarate dependent dioxygenase, designated as DPS (Dioxygenase for Potato Solanidane synthesis), that is a key enzyme for solanidane glycoalkaloid biosynthesis in potato. DPS catalyzes the ring-rearrangement from spirosolane to solanidane via C-16 hydroxylation. Evolutionary divergence of spirosolane-metabolizing dioxygenases contributes to the emergence of toxic solanidane glycoalkaloids in potato and the chemical diversity in Solanaceae.
Assuntos
Vias Biossintéticas , Dioxigenases/biossíntese , Dioxigenases/genética , Solanum tuberosum/enzimologia , Solanum tuberosum/genética , Sequência de Aminoácidos , Vias Biossintéticas/genética , Colesterol/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Hidroxilação , Ácidos Cetoglutáricos/metabolismo , Solanum lycopersicum/enzimologia , Solanum lycopersicum/genética , Filogenia , Plantas Geneticamente Modificadas , Metabolismo Secundário/genética , Metabolismo Secundário/fisiologia , Solanina/análogos & derivados , Solanum melongena/enzimologia , Solanum melongena/genética , Tomatina/análogos & derivados , Tomatina/metabolismoRESUMO
Cadmium (Cd) is recognized as a highly toxic heavy metal for humans in part because it is a multi-organ carcinogen. To clarify the mechanism of Cd carcinogenicity, we have established an experimental system using rat liver TRL1215 cells exposed to 2.5 µM Cd for 10 weeks and then cultured in Cd-free medium for an additional 4 weeks (total 14 weeks). Recently, we demonstrated, by using this experimental system, that 1) Cd stimulates cell invasion by suppression of apolipoprotein E (ApoE) expression, and 2) Cd induces DNA hypermethylation of the regulatory region of the ApoE gene. However, the underlying mechanism(s) as well as other potential genetic participants in the Cd-stimulated invasion are undefined. In the present work, we found that concurrent with enhanced invasion, Cd induced oxidative stress, coupled with the production of oxidative stress-sensitive metallothionein 2A (MT2A), which lead to down-modulation of ten-eleven translocation methylcytosine dioxygenase 1 (TET1: DNA demethylation) in addition to ApoE, without impacting DNA methyltransferases (DNMTs: DNA methylation) levels. Furthermore, the expression of tissue inhibitor of metalloproteinase 2 and 3 (TIMP2 and TIMP3) that are positively regulated by TET1, were decreased by Cd. The genes (ApoE/TET1/TIMP2/TIMP3) suppressed by Cd were further suppressed by hydroquinone (HQ; a reactive oxygen species [ROS] producer), whereas N-acetyl-l-cysteine (NAC; a ROS scavenger) prevented the suppression of their expression by HQ. In addition, NAC reversed their expression suppressed by Cd. Cd-stimulated cell invasion was clearly dampened by NAC in a concentration-dependent manner. Overall these findings suggest that 1) altered TET1 expression and activity together with ApoE are likely involved in the enhanced invasiveness due to Cd exposure, and 2) Cd down-regulation of TET1 likely evokes a reduction in ApoE expression (possible by DNA hypermethylation), and 3) anti-oxidants are effective in abrogation of the enhanced invasiveness that occurs concurrently with Cd-induced malignant transformation.
Assuntos
Cádmio/toxicidade , Dioxigenases/antagonistas & inibidores , Dioxigenases/biossíntese , Fígado/efeitos dos fármacos , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/fisiologia , Relação Dose-Resposta a Droga , Fígado/patologia , Invasividade Neoplásica/patologia , Estresse Oxidativo/fisiologia , Ratos , Ratos Endogâmicos F344RESUMO
Previously, Nucleolar protein 66 (NO66) was reported to be closely associated with alcohol exposure-induced injury. However, the role of NO66 in alcohol-induced cytotoxicity remains unclear. In this study, we explored the potential effect and mechanism of NO66 on ethanol-induced apoptosis in human AC16 cardiomyocytes. The AC16 cell lines with NO66 and phosphatase and tensin homolog (PTEN) overexpression were constructed. Cell counting kit-8 (CCK-8), lactate dehydrogenase (LDH) assay, Annexin V-FITC/PI staining, and flow cytometry were used to evaluate the cell viability, membrane damage, and apoptosis, respectively. Quantitative real-time PCR (qRT-PCR) and western blot analysis were applied to measure mRNA and protein expression. The results showed that acute ethanol exposure markedly augmented cytotoxicity and reduced NO66 level in AC16 cardiomyocytes. Overexpression of NO66 partially reversed ethanol-induced apoptosis. NO66 upregulation reversed the decrease in phosphorylation of protein kinase B (Akt) and B-cell lymphoma-2/Bcl-2-associated x (Bcl-2/Bax) ratio and the increase in PTEN, p53, and caspase-3 activity induced by ethanol treatment. Meanwhile, the application of PI3K inhibitor (LY294002) and PTEN overexpression attenuated the inhibition efficiency of NO66 on cell apoptosis. In addition, PTEN overexpression weakened the effect of NO66 on PI3K/Akt activation, without affecting the level of NO66. Our data suggested that NO66 overexpression might play an anti-apoptotic role in ethanol-induced cell injury via reducing PTEN and upregulating the PI3K/Akt pathway.
Assuntos
Apoptose/genética , Dioxigenases/biossíntese , Dioxigenases/genética , Histona Desmetilases/biossíntese , Histona Desmetilases/genética , Miócitos Cardíacos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Etanol/toxicidade , Humanos , Miócitos Cardíacos/efeitos dos fármacos , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/genética , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima , Proteína X Associada a bcl-2/metabolismoRESUMO
In this paper, we report the results of treating cells with an effective small molecule, (+)4-cholesten-3-one (PubChem CID: 91477), which can promote neural stem cell(NSC) differentiation into dopaminergic neurons. This study used rat neural stem cells stimulated with two different concentrations (7.8⯵M and 78⯵M) of (+)4-cholesten-3-one. Cell phenotypic analysis showed that (+)4-cholesten-3-one induced NSC differentiation into dopaminergic neurons, and the level of tyrosine hydroxylase(TH), which is specific for dopaminergic cells, was significantly increased compared with that of the drug-free control group. Furthermore, in this study, we found that this effect may be related to the transcription factor fork-head box a2 (FoxA2) and ten-eleven translocation 1 (TET1). The expression of TET1 and FoxA2 was upregulated after treatment with (+)4-cholesten-3-one. To verify the relationship between (+)4-cholesten-3-one and these genes, we found that the binding rate of TET1 and FoxA2 increased after the application of (+)4-cholesten-3-one, as confirmed by a coimmunoprecipitation (Co-IP) assay. With a small interfering RNA (siRNA) experiment, we found that only when Tet1 and Foxa2 were not silenced was the mRNA level of Th increased after (+)4-cholesten-3-one treatment. Taken together, these data show that (+)4-cholesten-3-one can promote the differentiation of NSCs into dopaminergic neurons by upregulating the expression of TET1 and FoxA2 and by increasing their binding. Thus, (+)4-cholesten-3-one may help address the application of neural stem cell replacement therapy in neurodegenerative diseases.
Assuntos
Diferenciação Celular/fisiologia , Colestenonas/farmacologia , Dioxigenases/biossíntese , Neurônios Dopaminérgicos/metabolismo , Fator 3-beta Nuclear de Hepatócito/biossíntese , Células-Tronco Neurais/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Neurônios Dopaminérgicos/efeitos dos fármacos , Feminino , Células-Tronco Neurais/efeitos dos fármacos , Gravidez , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Ratos , Ratos Sprague-DawleyRESUMO
Crocins and picrocrocin are glycosylated apocarotenoids responsible, respectively, for the color and the unique taste of the saffron spice, known as red gold due to its high price. Several studies have also shown the health-promoting properties of these compounds. However, their high costs hamper the wide use of these metabolites in the pharmaceutical sector. We have developed a virus-driven system to produce remarkable amounts of crocins and picrocrocin in adult Nicotiana benthamiana plants in only two weeks. The system consists of viral clones derived from tobacco etch potyvirus that express specific carotenoid cleavage dioxygenase (CCD) enzymes from Crocus sativus and Buddleja davidii. Metabolic analyses of infected tissues demonstrated that the sole virus-driven expression of C. sativus CsCCD2L or B. davidii BdCCD4.1 resulted in the production of crocins, picrocrocin and safranal. Using the recombinant virus that expressed CsCCD2L, accumulations of 0.2% of crocins and 0.8% of picrocrocin in leaf dry weight were reached in only two weeks. In an attempt to improve apocarotenoid content in N. benthamiana, co-expression of CsCCD2L with other carotenogenic enzymes, such as Pantoea ananatis phytoene synthase (PaCrtB) and saffron ß-carotene hydroxylase 2 (BCH2), was performed using the same viral system. This combinatorial approach led to an additional crocin increase up to 0.35% in leaves in which CsCCD2L and PaCrtB were co-expressed. Considering that saffron apocarotenoids are costly harvested from flower stigma once a year, and that Buddleja spp. flowers accumulate lower amounts, this system may be an attractive alternative for the sustainable production of these appreciated metabolites.
Assuntos
Carotenoides/metabolismo , Crocus/genética , Glucosídeos/biossíntese , Nicotiana , Plantas Geneticamente Modificadas , Potyvirus/genética , Crocus/enzimologia , Cicloexenos , Dioxigenases/biossíntese , Dioxigenases/genética , Glucosídeos/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Potyvirus/metabolismo , Terpenos , Nicotiana/genética , Nicotiana/metabolismoRESUMO
Ten-eleven translocation (TET) proteins have been shown to be abnormally expressed in different cancers. To investigate the expression pattern of TET proteins in HepG2 cells, sodium ascorbate was used to treat HepG2 cells. Our results showed that TET1, TET2 and TET3 expression was increased after sodium ascorbate treatment. The TET proteins catalyze the oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), thus, 5mC and 5hmC levels were examined. The results suggested that 5hmC was increased after sodium ascorbate treatment. To further determine the biological function of the TET proteins, si-TET1, si-TET2 and si-TET3 were transfected into HepG2 cells. The results showed that a knock down of TET3 expression stimulated cell proliferation of HepG2 cells. To further understand the effects of TET3 expression on cell proliferation, sodium ascorbate was added to the cells after transfection with si-TET3. The results demonstrated that sodium ascorbate could rescue TET3 expression and inhibit cell proliferation. Taken together, these results indicate that TET3 expression regulated cell proliferation, which is associated with 5hmC in HepG2 cells.
Assuntos
Dioxigenases/biossíntese , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Ácido Ascórbico/farmacologia , Proliferação de Células/fisiologia , Metilação de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Células Hep G2 , Humanos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Oxirredução , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , TranscriptomaRESUMO
Accurate reprogramming of DNA methylation occurring in preimplantation embryos is critical for normal development of both fetus and placenta. Environmental stresses imposed on oocytes usually cause the abnormal DNA methylation reprogramming of early embryos. However, whether oocyte vitrification alters the reprogramming of DNA methylation (5â¯mC) and its derivatives in mouse preimplantation embryo development remains largely unknown. Here, we found that the rate of cleavage and blastocyst formation of embryos produced by IVF of vitrified matured oocytes was significantly lower than that in control counterparts, but the quality of blastocysts was not impaired by oocyte vitrification. Additionally, although vitrification neither altered the dynamic changes of 5-hydroxymethylcytosine (5hmC) and 5-formylcytosine (5â¯fC) before 4-cell stage nor affected the levels of 5â¯mC and 5-carboxylcytosine (5caC) throughout the preimplantation development, vitrification significantly reduced the levels of 5hmC and 5â¯fC from 8-cell stage onwards. Correspondingly, vitrification did not alter the expression patterns of Tet3 in preimplantation embryos but apparently reduced the expression levels of Tet1 in 4-cell and 8-cell embryos and increased the expression levels of Tet2 at morula stage. Taken together, these results demonstrate that oocyte vitrification perturbs DNA methylation reprogramming in mouse preimplantation embryo development.
Assuntos
Blastocisto/citologia , Criopreservação/métodos , Metilação de DNA/genética , Oócitos/citologia , Oogênese/fisiologia , Vitrificação , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/química , Animais , Citosina/análogos & derivados , Citosina/química , Proteínas de Ligação a DNA/biossíntese , Dioxigenases/biossíntese , Desenvolvimento Embrionário , Feminino , Fertilização in vitro/métodos , Metáfase , Camundongos , Mórula/fisiologia , Gravidez , Proteínas Proto-Oncogênicas/biossínteseRESUMO
Mandelic acid (MA) and 4-hydroxymandelic acid (HMA) are valuable specialty chemicals used as precursors for flavors as well as for cosmetic and pharmaceutical purposes. Today they are mainly synthesized chemically. Their synthesis through microbial fermentation would allow for environmentally sustainable production. In this work, we engineered the yeast Saccharomyces cerevisiae for high-level production of MA and HMA. Expressing the hydroxymandelate synthase from Amycolatopsis orientalis in a yeast wild type strain resulted in the production of 119mg/L HMA from glucose. As the enzyme also accepts phenylpyruvate as a substrate aside from its native substrate 4-hydroxyphenylpyruvate, 0.7mg/L MA was also produced. Preventing binding of 4-hydroxyphenylpyruvate to the hydroxymandelate synthase by introducing a S201V replacement in its substrate binding site nearly completely prevented HMA production but increased MA production only 3.5-fold. To further increase HMA and MA production, the aromatic amino acid pathway was engineered. We increased the precursor supply by introducing modifications in the shikimic acid pathway (ARO1↑, ARO3K222L↑, ARO4K220L↑) and reducing flux into the Ehrlich pathway (aro10Δ), and thereby enhanced the HMA titer to 465mg/L and the MA titer to 2.9mg/L. A further increase in HMA and MA titers was achieved by replacing the hydroxymandelate synthase from A. orientalis with the corresponding enzyme from Nocardia uniformis. Subsequently, we introduced additional deletions to block the competing tryptophan branch (trp2Δ), to further decrease flux into the Ehrlich pathway (pdc5Δ) and to avoid transamination of phenylpyruvate and 4-hydroxyphenylpyruvate (aro8Δ, aro9Δ). We achieved more than 1g/L 4-hydroxymandelate when additionally preventing formation of phenylpyruvate by deleting PHA2. When deleting TYR1 to prevent formation of 4-hydroxyphenylpyruvate instead, an MA titer of 236mg/L was achieved. This is a more than 200-fold increase in MA production compared to the wild type strain expressing the hydroxymandelate synthase from A. orientalis. Finally, we showed that S. cerevisiae tolerates HMA and MA to concentrations as high as 3g/L and 7.5g/L, respectively. Our results demonstrate that S. cerevisiae is a promising host for sustainable MA and HMA production.
Assuntos
Actinobacteria/genética , Aminoácidos Aromáticos/metabolismo , Proteínas de Bactérias , Dioxigenases , Ácidos Mandélicos/metabolismo , Saccharomyces cerevisiae , Actinobacteria/enzimologia , Aminoácidos Aromáticos/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Dioxigenases/biossíntese , Dioxigenases/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMO
Drug craving and relapse risk during abstinence from cocaine are thought to be caused by persistent changes in transcription and chromatin regulation. Although several brain regions are involved in these processes, the hippocampus seems to play an important role in context-evoked craving and drug-seeking behavior. Only a few studies have examined epigenetic alterations during a period of cocaine abstinence. To investigate the effects of cocaine abstinence on DNA methylation and gene expression, rats that self-administered the drug underwent cocaine abstinence in two time points with extinction training. During the cocaine extinction, we observed elevated global 5-hydroxymethylcytosine(5-hmC) levels with a concurrent increase in Tet3 transcript levels. Moreover, we did not find significant alterations in the levels of Tet3 mRNA and 5-hmC in rats subjected to cocaine abstinence without extinction training. Additionally, our findings demonstrated that the expression of Tet3 target genes was activated. Besides, altered DNA methylation was detected at promoter regions of miRNAs, such as miR-30d and miR-let7i. Further in silico analysis provided evidence that these two molecules targeted the 3' UTR region of the Tet3 gene and thus may contribute to its post-transcriptional regulation. This study has presented novel findings in the hippocampus of rats that underwent extinction training following cocaine self-administration. The alterations in the Tet3 gene expression and the level of 5-hmC may play an important role in extinction learning and the reduction of subsequent cocaine seeking.
Assuntos
5-Metilcitosina/análogos & derivados , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Hipocampo/metabolismo , 5-Metilcitosina/metabolismo , Animais , Transtornos Relacionados ao Uso de Cocaína/genética , Metilação de DNA , Dioxigenases/biossíntese , Dioxigenases/genética , Extinção Psicológica , Regulação da Expressão Gênica/fisiologia , Masculino , Ratos , Ratos WistarRESUMO
9-cis-epoxycarotenoid dioxygenase (NCED) encodes a key enzyme in abscisic acid (ABA) biosynthesis. Little is known regarding the regulation of stress response by NCEDs at physiological levels. In the present study, we generated transgenic tobacco overexpressing an NCED3 ortholog from citrus (CsNCED3) and investigated its relevance in the regulation of drought stress tolerance. Wild-type (WT) and transgenic plants were grown under greenhouse conditions and subjected to drought stress for 10 days. Leaf predawn water potential (Ψwleaf), stomatal conductance (gs), net photosynthetic rate (A), transpiration rate (E), instantaneous (A/E) and intrinsic (A/gs) water use efficiency (WUE), and in situ hydrogen peroxide (H2O2) and abscisic acid (ABA) production were determined in leaves of irrigated and drought-stressed plants. The Ψwleaf decreased throughout the drought stress period in both WT and transgenic plants, but was restored after re-watering. No significant differences were observed in gs between WT and transgenic plants under normal conditions. However, the transgenic plants showed a decreased (P ≤ 0.01) gs on the 4th day of drought stress, which remained lower (P ≤ 0.001) than the WT until the end of the drought stress. The A and E levels in the transgenic plants were similar to those in WT; therefore, they exhibited increased A/gs under drought conditions. No significant differences in A, E, and gs values were observed between the WT and transgenic plants after re-watering. The transgenic plants had lower H2O2 and higher ABA than the WT under drought conditions. Our results support the involvement of CsNCED3 in drought avoidance.
Assuntos
Dioxigenases/biossíntese , Nicotiana/fisiologia , Proteínas de Plantas/biossíntese , Ácido Abscísico/biossíntese , Adaptação Fisiológica , Citrus/enzimologia , Citrus/genética , Dioxigenases/genética , Dioxigenases/metabolismo , Secas , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico , Nicotiana/enzimologia , Nicotiana/genética , Nicotiana/metabolismoRESUMO
Ten-eleven translocation proteins are α-ketoglutarate-dependent dioxygenases involved in the conversion of 5-methylcytosines (5-mC) to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine, and 5-carboxylcytosine that play a significant role in DNA demethylation. Deregulation of TET genes expression and changes in the level of 5-hmC are thought to be associated with the onset and progression of several types of cancer, but there are no such data related to endometrial cancer. The aim of the work was to investigate the messenger RNA expression levels of TET1, TET2, and TET3 in relation to clinicopathological characteristics of endometrial cancer as well as the correlation between expression of TET genes and the level of 5-hmC/5-mC. The prognostic significance of TETs expression for overall survival was established. We found that TET1 and TET2 messenger RNA expression was lower and TET3 was higher in cancers compared to normal tissues. Positive correlation between 5-hmC and the relative expression of TET1 and TET2 was found, but no correlation was observed in the case of TET3. Decreased expression of TET1 and TET2 was significantly associated with increased lymph node metastasis and International Federation of Gynecology and Obstetrics stage. Kaplan-Meier analysis indicated that low TET1 expression predicted poor overall survival (p = 0.038). Multivariate analysis identified the TET1 expression in endometrial cancer as an independent prognostic factor. Our results suggest that decreased expression of TET1 correlates with tumor progression and may serve as a potential prognostic biomarker in endometrial cancer.
Assuntos
Metilação de DNA/genética , Proteínas de Ligação a DNA/biossíntese , Dioxigenases/biossíntese , Neoplasias do Endométrio/genética , Oxigenases de Função Mista/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Idoso , Citosina/análogos & derivados , Citosina/metabolismo , Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Epigênese Genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Oxigenases de Função Mista/genética , Prognóstico , Proteínas Proto-Oncogênicas/genéticaRESUMO
Selection for yellow- and white-grain types has been central to postdomestication improvement of maize. While genetic control of carotenoid biosynthesis in endosperm is attributed primarily to the Yellow1 (Y1) phytoene synthase gene, less is known about the role of the dominant white endosperm factor White Cap (Wc). We show that the Wc locus contains multiple, tandem copies of a Carotenoid cleavage dioxygenase 1 (Ccd1) gene that encodes a carotenoid-degrading enzyme. A survey of 111 maize inbreds and landraces, together with 22 teosinte accessions, reveals that Wc is exclusive to maize, where it is prevalent in white-grain (y1) varieties. Moreover, Ccd1 copy number varies extensively among Wc alleles (from 1 to 23 copies), and confers a proportional range of Ccd1 expression in diverse organs. We propose that this dynamic source of quantitative variation in Ccd1 expression was created in maize shortly after domestication by a two-step, Tam3L transposon-mediated process. First, a chromosome segment containing Ccd1 and several nearby genes duplicated at a position 1.9 Mb proximal to the progenitor Ccd1r locus on chromosome 9. Second, a subsequent interaction of Tam3L transposons at the new locus created a 28-kb tandem duplication, setting up expansion of Ccd1 copy number by unequal crossing over. In this way, transposon-mediated variation in copy number at the Wc locus generated phenotypic variation that provided a foundation for breeding and selection of white-grain color in maize.
Assuntos
Evolução Biológica , Dioxigenases/genética , Grão Comestível/genética , Proteínas de Plantas/genética , Zea mays/genética , Alelos , Cruzamento , Carotenoides/biossíntese , Carotenoides/genética , Mapeamento Cromossômico , Cor , Variações do Número de Cópias de DNA , Dioxigenases/biossíntese , Grão Comestível/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Filogenia , Pigmentos Biológicos/biossíntese , Pigmentos Biológicos/genética , Proteínas de Plantas/biossíntese , Seleção Genética , Zea mays/crescimento & desenvolvimentoRESUMO
A key issue towards developing new chemotherapeutic approaches to fight Mycobacterium tuberculosis is to understand the mechanisms underlying drug resistance. Previous studies have shown that genes Rv1686c-Rv1687c and Rv3161c, predicted to encode an ATP-binding cassette transporter and a dioxygenase respectively, are induced in the presence of triclosan and other antimicrobial compounds. Therefore a possible role in drug resistance has been suggested for the products of these genes although no functional studies have been done. The aim of the present study was to clarify the role of Rv1686c-Rv1687c and Rv3161c in M. tuberculosis resistance to triclosan and other drugs. To this end, deficient mutants and overproducing strains for both systems were constructed and their minimal inhibitory concentration (MIC) against over 20 compounds, including triclosan, was evaluated. Unexpectedly, no differences between the MIC of these strains and the wild-type H37Rv were observed for any of the compounds tested. Moreover the MIC of triclosan was not affected by efflux pump inhibitors that inhibit the activity of transporters similar to the one encoded by Rv1686c-Rv1687c. These results suggest that none of the two systems is directly involved in M. tuberculosis resistance to triclosan or to any of the antimicrobials tested.