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1.
iScience ; 27(5): 109678, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38660411

RESUMO

The liver is the main organ associated with metabolism. In our previous studies, we identified that the metabolic enzymes malate dehydrogenase 1 (MDH1) and isocitrate dehydrogenase 1 (IDH1) were differentially expressed in ALF. The aim of this study was to explore the changes in the acetylation of MDH1 and IDH1 and the therapeutic effect of histone deacetylase (HDAC) inhibitor in acute liver failure (ALF). Decreased levels of many metabolites were observed in ALF patients. MDH1 and IDH1 were decreased in the livers of ALF patients. The HDAC inhibitor ACY1215 improved the expression of MDH1 and IDH1 after treatment with MDH1-siRNA and IDH1-siRNA. Transfection with mutant plasmids and adeno-associated viruses, identified MDH1 K118 acetylation and IDH1 K93 acetylation as two important sites that regulate metabolism in vitro and in vivo.

2.
Front Psychol ; 15: 1252864, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38449757

RESUMO

Aim: This study examined the association between self-reported nature exposure and depression among Chinese prisoners, as well as the mediating and moderating effects of meaning in life and callous-unemotional (CU) traits, respectively. Background: Prisoners are more likely to experience depression than any other mental illness. Exposure to nature has been proposed as a highly cost-effective method of treating their depressive symptoms. However, the mechanism underlying the link between nature exposure and depression among prisoners needs further investigation, as the findings may provide new insights into how to address depression in incarcerated populations. Method: Data were collected through a survey conducted in four prisons in southern China from April to May 2022. The participants were 574 prisoners who anonymously completed four questionnaires about nature exposure, meaning in life, depression, and CU traits. Results: The results show that: (1) meaning in life significantly mediates the association between nature exposure and depression, and (2) CU traits moderate the connection between nature exposure and meaning in life. Conclusion: The current study uncovered that prisoners who contact more with the natural environment have a higher meaning in life and lower depression, and individuals with higher CU traits can benefit more from nature exposure.

3.
Hepatobiliary Pancreat Dis Int ; 23(1): 43-51, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36966125

RESUMO

BACKGROUND: Acute liver failure (ALF) is an unpredictable and life-threatening critical illness. The pathological characteristic of ALF is massive necrosis of hepatocytes and lots of inflammatory cells infiltration which may lead to multiple organ failure. METHODS: Animals were divided into 3 groups, normal, thioacetamide (TAA, ALF model) and TAA + AGK2. Cultured L02 cells were divided into 5 groups, normal, TAA, TAA + mitofusin 2 (MFN2)-siRNA, TAA + AGK2, and TAA + AGK2 + MFN2-siRNA groups. The liver histology was evaluated with hematoxylin and eosin staining, inositol-requiring enzyme 1 (IRE1), activating transcription factor 6ß (ATF6ß), protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and phosphorylated-PERK (p-PERK). C/EBP homologous protein (CHOP), reactive oxygen species (ROS), MFN2 and glutathione peroxidase 4 (GPX4) were measured with Western blotting, and cell viability and liver chemistry were also measured. Mitochondria-associated endoplasmic reticulum membranes (MAMs) were measured by immunofluorescence. RESULTS: The liver tissue in the ALF group had massive inflammatory cell infiltration and hepatocytes necrosis, which were reduced by AGK2 pre-treatment. In comparison to the normal group, apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ in the TAA-induced ALF model group were significantly increased, which were decreased by AGK2 pre-treatment. The levels of MFN2 and GPX4 were decreased in TAA-induced mice compared with the normal group, which were enhanced by AGK2 pre-treatment. Compared with the TAA-induced L02 cell, apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ were further increased and levels of MFN2 and GPX4 were decreased in the MFN2-siRNA group. AGK2 pre-treatment decreased the apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ and enhanced the protein expression of MFN2 and GPX4 in MFN2-siRNA treated L02 cell. Immunofluorescence observation showed that level of MAMs was promoted in the AGK2 pre-treatment group when compared with the TAA-induced group in both mice and L02 cells. CONCLUSIONS: The data suggested that AGK2 pre-treatment had hepatoprotective role in TAA-induced ALF via upregulating the expression of MFN2 and then inhibiting PERK and ferroptosis pathway in ALF.


Assuntos
Ferroptose , Falência Hepática Aguda , Camundongos , Animais , Tioacetamida/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/prevenção & controle , Transdução de Sinais , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/efeitos adversos , Proteínas Serina-Treonina Quinases/metabolismo , Apoptose , Necrose , RNA Interferente Pequeno/efeitos adversos , Estresse do Retículo Endoplasmático/genética
4.
Int J Mol Med ; 53(1)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37997858

RESUMO

Vitamin K (VK), a fat­soluble vitamin, is well known as an anticoagulant in the clinic. It is essential for the post­translational activation of VK­dependent proteins (VKDPs) because hydroquinone VK is a cofactor of glutamine carboxylase. At present, 17 VKDPs are known, which are mainly involved in coagulation and calcification. When Glu residues are carboxylated to Gla residues, these proteins gain a higher calcium­binding ability, which explains why VK has an important role in blood coagulation and biomineralization. However, the current view on the role of VK and several VKDPs in biomineralization remains inconsistent. For instance, conflicting results have been reported regarding the effect of osteocalcin gene knockout on the bone of mice; matrix Gla protein (MGP) promotes osteoblasts mineralization but inhibits vascular smooth muscle cell mineralization. The present review aimed to summarize the existing evidence that several VKDPs, including osteocalcin, MGP, Gla­rich protein and growth arrest specific 6 are closely related to calcification, including bone health, vascular calcification and lithiasis. The current review discussed these controversies and provided suggestions for future studies on VKDPs, i.e. taking into account dietary habits, geographical environments and genetic backgrounds.


Assuntos
Calcificação Vascular , Vitamina K , Camundongos , Animais , Vitamina K/metabolismo , Osteocalcina/genética , Osteocalcina/metabolismo , Biomineralização , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Calcificação Vascular/genética , Osso e Ossos/metabolismo
5.
Toxicol Lett ; 392: 1-11, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38103582

RESUMO

Sodium dehydroacetate (DHA-S), a potent antifungal and antibacterial agent, is widely used in food, feed and cosmetics. However, recent studies have shown that DHA-S could pose a risk for human and animal health. We had previously reported that DHA-S could cause coagulation disorders in rats and chicken. In the present study, we further confirmed that DHA-S induced blood coagulation via VKORC1 and VKORC1L1 in rats, and elucidated the role played by mTOR/ERK signaling. The in vivo studies demonstrated that PT, APTT, and DHA-S content and relative protein expressions in tissues rebounded after drug withdrawal. In BRL-3A cells, 1.0 mM DHA-S increased the expression levels of mTOR, p-mTOR and p-ERK and decreased the levels of VKORC1, VKORC1L1 and Vitamin K. Rapamycin significantly decreased the expression levels of p-mTOR and p-ERK, while FR180204 (p-ERK Inhibition) lead to a decrease in p-ERK level. Rapamycin and FR180202 attenuated the inhibitory effect of DHA-S on VKORC1, VKORC1L1 and vitamin K levels. In addition, DHA-S increased the expression levels of mTOR, p-mTOR and p-ERK in male and female rat livers and prolonged PT and APTT. In summary, this study indicated that DHA-S induced blood coagulation via the modulation of the mTOR/ERK pathway in rats.


Assuntos
Coagulação Sanguínea , Sistema de Sinalização das MAP Quinases , Pironas , Humanos , Ratos , Masculino , Feminino , Animais , Vitamina K Epóxido Redutases/metabolismo , Vitamina K , Serina-Treonina Quinases TOR/metabolismo , Sirolimo/farmacologia
6.
Behav Sci (Basel) ; 13(10)2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37887479

RESUMO

The frequent occurrences of cyberbullying on social platforms have sparked a great deal of social conflict, and bystander intervention plays a crucial role in preventing the escalation of cyberbullying. This research examines the impact of victim self-disclosure on bystander intervention in cyberbullying through two experimental studies. The studies collected data from March to July of 2022, utilizing a convenience sampling approach to recruit university students as experiment participants. Study 1 recruited 247 valid participants, while Study 2 recruited 522 eligible participants. The results of Study 1 indicate that the perceptible dimensions (frequency, privacy, and valence) of victim self-disclosure impact bystander intervention. Specifically, in a low privacy context, positive self-disclosure increases bystander intervention, while negative self-disclosure does the opposite. The results of Study 2 suggest that the valence of self-disclosure affects bystander intervention through the mediation of victim blaming, with interpersonal distance moderating the impact of victim self-disclosure valence on the extent of victim blaming. This moderated mediation model clarifies the psychological process by which the valence of victim self-disclosure affects bystander intervention. The findings of this study contribute to the understanding of the social psychological process behind bystander intervention, providing a scientific basis and pathway for reducing cyberbullying and fostering a harmonious online environment.

7.
Front Public Health ; 11: 1218825, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37601183

RESUMO

Objective: This study examined the prevalence of anxiety and depression-along with the potential risk and protective factors-among Chinese prison officers during the prolonged COVID-19 pandemic. Method: A cross-sectional survey of 1,268 officers from five prisons in western and southern China was administered between June and July 2022. The questionnaires comprised two sections. In the first section, the Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) were used to evaluate the prevalence of anxiety and depression, respectively, among prison officers. In the second section, the potential influencing factors were examined. Categorical data were compared using χ2 tests and t-tests; binary logistic regression analysis was performed to identify factors associated with anxiety and depression. Results: The prevalence rates of anxiety and depression among the prison officers were 72.6% and 69.8%, respectively. Risk factors for anxiety were older age, being unmarried, work-family conflicts, job demands, and COVID-19 burnout; protective factors were exercise, positive family relationships, and group cohesion. Work-family conflicts, job demands, intolerance of uncertainty regarding COVID-19, and COVID-19 burnout were risk factors for depression, whereas annual income >150,000 RMB, exercise, positive family relationships, group cohesion, and job autonomy were protective factors against depression. Conclusion: The prevalence of anxiety and depression among Chinese prison officers was relatively high during the prolonged COVID-19 pandemic, and more targeted measures should be implemented to improve their mental health. This study offers a reference for improving prison officers' mental health in response to similar public health emergencies in the future.


Assuntos
Ansiedade , COVID-19 , Servidores Penitenciários , Depressão , Humanos , Ansiedade/epidemiologia , Transtornos de Ansiedade/epidemiologia , COVID-19/epidemiologia , COVID-19/psicologia , Estudos Transversais , Depressão/epidemiologia , População do Leste Asiático , Pandemias , Prevalência , Prisões/estatística & dados numéricos , Servidores Penitenciários/psicologia , Servidores Penitenciários/estatística & dados numéricos
8.
Behav Sci (Basel) ; 13(7)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37504005

RESUMO

The COVID-19 pandemic has brought enormous challenges to both employees and organizations all over the world. Previous studies have found high turnover rates among prison officers since the outbreak of COVID-19. This cross-sectional study aimed to investigate the mediating role of job burnout between job demands and turnover intention, as well as the moderating role of the perceived efficacy in overcoming COVID-19 in Chinese prison officers. In total, 1316 prison officers were recruited to complete an online questionnaire between May 2022 and June 2022 (during the COVID-19 pandemic). The bootstrapping approach was used to assess the moderated mediation model in this study. The results showed that prison officers' job demands were positively associated with their turnover intention. Job burnout mediated the relationship between job demands and turnover intention. Perceived efficacy in overcoming COVID-19 moderated the effect of job burnout on turnover intention. Based on these results, suggestions were provided to reduce the high turnover rate of prison officers in public health events like the COVID-19 pandemic.

9.
J Inflamm (Lond) ; 20(1): 24, 2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37443080

RESUMO

BACKGROUND: Acute liver failure (ALF) is one of the most common life-threatening diseases in adults without previous liver disease. Glycogen synthase kinase 3ß (GSK3ß) is a serine/threonine protein kinase that is widely distributed in the cells. Inhibition of its activity can inhibit cell death and promote autophagy through various pathways, thus providing a protective effect. In this study, we aimed to investigate the effect on ALF after inhibition of GSK3ß and its potential mechanisms. METHODS: D- galactosamine(D-Gal) in combination with lipopolysaccharide(LPS) was used to induce ALF in vitro and in vivo. And then GSK3ß inhibitor TDZD-8 was used to explore the protective effect against ALF. After TDZD-8 treatment TUNEL staining and flow techniques were used to detect the proportion of apoptosis in liver tissues and cells respectively, while western blotting and immunofluorescence assays were performed to detect the expression levels of apoptosis, pyroptosis and necroptosis-related proteins in tissues and cells. In addition, western blotting was performed to explore the specific mechanism of hepatoprotective effect after GSK3ß inhibition to detect the expression levels of TAK1, TRAF6 and HDAC3 after TRAF6 and HDAC3 inhibition alone. The co-localization of TRAF6 and HDAC3 in vitro was detected by immunofluorescence, while the interaction between TRAF6 and HDAC3 was detected by immunoprecipitation assay. RESULTS: Both in vivo and in vitro experiments, GSK3ß inhibitor TDZD-8 can significantly alleviate the progression of ALF. Inhibition of GSK3ß activity could significantly reduce the level of hepatocyte apoptosis, pyroptosis, necroptosis and improve liver dysfunction and tissue damage. Furthermore, we found that hepatocyte TAK1 and TRAF6 levels decreased and HDAC3 levels increased in ALF, whereas inhibition of GSK3ß upregulated TAK1 and TRAF6 levels and decreased HDAC3 expression. CONCLUSION: GSK3ß inhibitor TDZD-8 can prevent the progression of ALF, and its action may involve the TRAF6/HDAC3/TAK1 pathway.

10.
J Inflamm Res ; 16: 1523-1532, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37077221

RESUMO

PANoptosis is a new cell death proposed by Malireddi et al in 2019, which is characterized by pyroptosis, apoptosis and necroptosis, but cannot be explained by any of them alone. The interaction between pyroptosis, apoptosis and necroptosis is involved in PANoptosis. In this review, from the perspective of PANoptosis, we focus on the relationship between pyroptosis, apoptosis and necroptosis, the key molecules in the process of PANoptosis and the formation of PANoptosome, as well as the role of PANoptosis in diseases. We aim to understand the mechanism of PANoptosis and provide a basis for targeted intervention of PANoptosis-related molecules to treat human diseases.

11.
Aquac Nutr ; 2023: 9889533, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36860981

RESUMO

An 8-week feeding trial was performed to evaluate the effects of dietary ß-hydroxy-ß-methylbutyrate (HMB) supplementation on growth performance and muscle quality of kuruma shrimp (Marsupenaeus japonicas) (initial weight: 2.00 ± 0.01 g) fed a low protein diet. The positive control diet (HP) with 490 g/kg protein and negative control diet (LP) with 440 g/kg protein were formulated. Based on the LP, 0.25, 0.5, 1, 2 and 4 g/kg ß-hydroxy-ß-methylbutyrate calcium were supplemented to design the other five diets named as HMB0.25, HMB0.5, HMB1, HMB2 and HMB4, respectively. Results showed that compared with the shrimp fed LP, the HP, HMB1 and HMB2 groups had significantly higher weight gain and specific growth rate, while significantly lower feed conversion ratio (p < 0.05). Meanwhile, intestinal trypsin activity was significantly elevated in the above three groups than that of the LP group. Higher dietary protein level and HMB inclusion upregulated the expressions of target of rapamycin, ribosomal protein S6 kinase, phosphatidylinositol 3-kinase, and serine/threonine-protein kinase in shrimp muscle, accompanied by the increases in most muscle free amino acids contents. Supplementation of 2 g/kg HMB in a low protein diet improved muscle hardness and water holding capacity of shrimp. Total collagen content in shrimp muscle increased with increasing dietary HMB inclusion. Additionally, dietary inclusion of 2 g/kg HMB significantly elevated myofiber density and sarcomere length, while reduced myofiber diameter. In conclusion, supplementation of 1-2 g/kg HMB in a low protein diet improved the growth performance and muscle quality of kuruma shrimp, which may be ascribed to the increased trypsin activity and activated TOR pathway, as well as elevated muscle collagen content and changed myofiber morphology caused by dietary HMB.

12.
Therap Adv Gastroenterol ; 15: 17562848221138676, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36506748

RESUMO

Over the past two decades, non-alcoholic fatty liver disease (NAFLD) has become a leading burden of hepatocellular carcinoma and liver transplantation. Although the exact pathogenesis of NAFLD has not been fully elucidated, recent hypotheses placed more emphasis on the crucial role of the gut microbiome and its derivatives. Reportedly, microbial metabolites such as short-chain fatty acids, amino acid metabolites (indole and its derivatives), bile acids (BAs), trimethylamine N-oxide (TMAO), and endogenous ethanol exhibit sophisticated bioactive properties. These molecules regulate host lipid, glucose, and BAs metabolic homeostasis via modulating nutrient absorption, energy expenditure, inflammation, and the neuroendocrine axis. Consequently, a broad range of research has studied the therapeutic effects of microbiota-derived metabolites. In this review, we explore the interaction of microbial products and NAFLD. We also discuss the regulatory role of existing NAFLD therapies on metabolite levels and investigate the potential of targeting those metabolites to relieve NAFLD.

13.
J Cell Mol Med ; 26(21): 5528-5538, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36226351

RESUMO

Acute liver failure (ALF) is life-threatening and often associated with high mortality rates. The aim of the present study was to investigate whether extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF and explore its potential mechanism. RAW264.7 macrophages and C57BL/6 mice were used in this study. LPS, D-galactosamine (D-Gal), histone H3, histone H3 antibody, NOD2 agonist Muramyl Dipeptide (MDP) and HDAC6-siRNA were administered in this study. The key molecules of ferroptosis, NOD2, HDAC6 and the NF-κb pathway, were detected. In vitro, histone H3 was released into the extracellular environment from cell nucleus after LPS exposure. In addition, histone H3 could induce ferroptosis in RAW264.7 macrophages with increased level of Fe2+ and ROS and decreased levels of GPX4 and GSH. MDP further aggravated ferroptosis in RAW264.7 macrophages stimulated by histone H3, which was accompanied by elevated NOD2, HDAC6, p-P65 and IκBα. HDAC6-siRNA ameliorated ferroptosis in RAW264.7 macrophages induced by histone H3, which was accompanied by decreased levels of HDAC6, p-P65 and IκBα. However, HDAC6-siRNA did not alter NOD2 levels in RAW264.7 macrophages administered histone H3. In vivo, the levels of NOD2, HDAC6 the NF-κb pathway and ferroptosis were increased in ALF mice, which were downregulated by histone H3 antibody and upregulated by histone H3. Extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF by regulating theNOD2-mediated HDAC6/NF-κb signalling pathway.


Assuntos
Ferroptose , Falência Hepática Aguda , Animais , Camundongos , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Histonas , Lipopolissacarídeos , Falência Hepática Aguda/induzido quimicamente , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Inibidor de NF-kappaB alfa/metabolismo , RNA Interferente Pequeno/genética
14.
Sci Rep ; 10(1): 13202, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764599

RESUMO

RNA silencing is a conserved mechanism in eukaryotic organisms to regulate gene expression. Argonaute (AGO), Dicer-like (DCL) and RNA-dependent RNA polymerase (RDR) proteins are critical components of RNA silencing, but how these gene families' functions in sugarcane were largely unknown. Most stress-resistance genes in modern sugarcane cultivars (Saccharum spp.) were originated from wild species of Saccharum, for example S. spontaneum. Here, we used genome-wide analysis and a phylogenetic approach to identify four DCL, 21 AGO and 11 RDR genes in the S. spontaneum genome (termed SsDCL, SsAGO and SsRDR, respectively). Several genes, particularly some of the SsAGOs, appeared to have undergone tandem or segmental duplications events. RNA-sequencing data revealed that four SsAGO genes (SsAGO18c, SsAGO18b, SsAGO10e and SsAGO6b) and three SsRDR genes (SsRDR2b, SsRDR2d and SsRDR3) tended to have preferential expression in stem tissue, while SsRDR5 was preferentially expressed in leaves. qRT-PCR analysis showed that SsAGO10c, SsDCL2 and SsRDR6b expressions were strongly upregulated, whereas that of SsAGO18b, SsRDR1a, SsRDR2b/2d and SsRDR5 was significantly depressed in S. spontaneum plants exposed to PEG-induced dehydration stress or infected with Xanthomonas albilineans, causal agent of leaf scald disease of sugarcane, suggesting that these genes play important roles in responses of S. spontaneum to biotic and abiotic stresses.


Assuntos
Proteínas Argonautas/genética , Estudo de Associação Genômica Ampla , RNA Polimerase Dependente de RNA/genética , Ribonuclease III/genética , Saccharum/genética , Cromossomos de Plantas/genética , Simulação por Computador , Regiões Promotoras Genéticas/genética , Mapeamento de Interação de Proteínas , Saccharum/enzimologia , Saccharum/metabolismo
16.
J Virol Methods ; 140(1-2): 212-7, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17140672

RESUMO

In the studies of expressing various foreign peptides using a TMV-based vector, a portion of morphologically altered progeny viral particles from some recombinant TMV constructs were detected by transmission electron microscopy in the first systematically infected upper leaves, but not in the fully expanded inoculated leaves, from infected tobacco plants. Furthermore, in vitro stability of such recombinant TMV constructs were lower than those of the wild type and other recombinant TMV constructs able to form regular rod-shape virions, hence causing the lower yields of recombinant viral particles purified from the infected tobacco plants. Our studies revealed that the presence of a cysteine residue in the foreign peptides, regardless of its position and the peptide sequence, was directly related to changes in the morphology and stability of these TMV recombinants.


Assuntos
Proteínas do Capsídeo/genética , Cisteína/química , Nicotiana/virologia , Vírus do Mosaico do Tabaco/genética , Vírion/ultraestrutura , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Peptídeos/química , Peptídeos/genética , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Vírus do Mosaico do Tabaco/metabolismo , Vírus do Mosaico do Tabaco/ultraestrutura , Vírion/química , Vírion/genética
17.
Gene ; 377: 140-9, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16797881

RESUMO

Nitrate reductase (NR) catalyzes NAD (P) H dependent reduction of nitrate to nitrite. Transformation systems have been established in several species of green algae by nitrate reductase gene functional complementation. In this report, an endogenous NR cDNA (3.4 kb) and a genomic fragment (14.6 kb) containing the NR gene (DvNIA1) were isolated from the D. viridis cDNA and genomic libraries respectively. Southern blot and Northern blot analyses showed that this gene exists as a single copy in D. viridis and is induced by nitrate. To obtain a NR defective mutant as a recipient strain, D. viridis cells were treated with a chemical mutagen and then cultured on a chlorate-containing plate to enrich chlorate tolerant mutants. Southern analysis showed that one isolate, B14, had a deletion in the DvNIA1 gene region. Using electroporation conditions determined in this laboratory, plasmid pDVNR containing the intact DvNIA1 gene has been electroporated into the defective mutant B14. Strains retaining a nitrate assimilation phenotype were obtained from nitrate plates after spreading the electroporated cells. In some individual strains, transcription of the introduced gene was detected. NR activity in these strains was slightly higher than that in the defective B14 cell, but excretion of nitrite into culture media was almost as high as that of the wild-type cell. Possible episomal presence of the introduced DNA in D. viridis is discussed.


Assuntos
Clorófitas/enzimologia , Clorófitas/genética , Nitrato Redutase/genética , Sequência de Aminoácidos , Sequência de Bases , DNA de Algas/genética , Expressão Gênica , Genes , Teste de Complementação Genética , Dados de Sequência Molecular , Mutação , Plasmídeos/genética , Homologia de Sequência de Aminoácidos , Transformação Genética
18.
Virology ; 348(2): 253-9, 2006 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-16542697

RESUMO

With regard to the effects of various foreign peptides fused to the coat protein subunits on the infectivity of corresponding TMV recombinants, some of TMV recombinants were found to induce necrotic local lesions on the inoculated leaves of susceptible tobacco. This paper reported that there existed a group of TMV recombinants in which the fused foreign peptides contained a transmembrane domain according to the predictions by three programs of SOSUI, TMpred and DAS. Further studies showed for the first time that a foreign transmembrane domain in a fused peptide of the corresponding TMV recombinant would result in the local lesions on the susceptible tobacco leaves. In addition, it was concluded that none of the TMV recombinants that systematically infected susceptible tobacco contained a transmembrane domain in the coat protein subunits.


Assuntos
Proteínas do Capsídeo/genética , Nicotiana/virologia , Vírus do Mosaico do Tabaco/genética , Vírus do Mosaico do Tabaco/patogenicidade , Sequência de Aminoácidos , Proteínas do Capsídeo/química , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/genética , Doenças das Plantas/virologia , Plasmídeos/genética , Estrutura Terciária de Proteína , Subunidades Proteicas , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Recombinação Genética
19.
Biochem Biophys Res Commun ; 340(1): 95-104, 2006 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-16359638

RESUMO

A sodium-dependent phosphate transporter gene, DvSPT1, was isolated from a cDNA library using a probe derived from a subtracted cDNA library of Dunaliella viridis. Sequencing analyses revealed a cDNA sequence of 2649 bp long and encoded an open-reading frame consisting of 672 amino acids. The deduced amino acid sequence of DvSPT1 exhibited 31.2% identity to that of TcPHO from Tetraselmis chui. Hydrophobicity and secondary structure prediction revealed 11 conserved transmembrane domains similar to those found in PHO89 from Saccharomyces cerevisiae and PHO4 from Neurospora crassa. Northern blot analysis indicated that the DvSPT1 expression was induced upon NaCl hyperosmotic stress or phosphate depletion. Functional characterization in yeast Na+ export pump mutant G19 suggested that DvSPT1 encoded a Na+ transporter protein. The gene sequence of GDvSPT1 (7922 bp) was isolated from a genomic library of D. viridis. Southern blot analysis indicated that there exist at least two homologous genes in D. viridis.


Assuntos
Chlamydomonas/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato/química , Proteínas Cotransportadoras de Sódio-Fosfato/metabolismo , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Peso Molecular , Homologia de Sequência de Aminoácidos , Proteínas Cotransportadoras de Sódio-Fosfato/isolamento & purificação
20.
Vaccine ; 24(2): 109-15, 2006 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-16337317

RESUMO

Based upon a mutant isolated from tobacco infected with a recombinant tobacco mosaic virus (TMV), a new TMV-based vector was developed in which four to six C-terminal amino acid residues were deleted from the viral coat protein (CP) subunit. The new vector was quite similar to the original TMV-based vector, which all expressed a well characterized epitope peptide F11 (P(142)-A(152)) of VP1 from foot-and-mouth disease virus (FMDV) serotype O in tobacco, in the infectivity, yield of the virus particles and more importantly protective activity of F11 in guinea pigs and swine against the FMDV. Furthermore, the capacity of the length of foreign peptide encoded by this new vector was much improved to successfully express a peptide F25 containing two fused epitopes F14 (R(200)-L(213)) and F11 of FMDV VP1, which was failed using the original vector in tobacco. Although animal assays indicated that such expressed F25 was not as efficient as F11 in the immunity, possibly due to lack of a spacer arm between the two fused epitopes, the new TMV-based vector may meet the requirement of expressing longer foreign peptides for different vaccines and other medicines.


Assuntos
Epitopos/genética , Vetores Genéticos , Nicotiana/genética , Planticorpos , Vírus do Mosaico do Tabaco/genética , Sequência de Bases , Primers do DNA
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