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1.
Int J Mol Sci ; 24(23)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38068884

RESUMO

Monovalent cation proton antiporters (CPAs) play crucial roles in ion and pH homeostasis, which is essential for plant development and environmental adaptation, including salt tolerance. Here, 68 CPA genes were identified in soybean, phylogenetically dividing into 11 Na+/H+ exchangers (NHXs), 12 K+ efflux antiporters (KEAs), and 45 cation/H+ exchangers (CHXs). The GmCPA genes are unevenly distributed across the 20 chromosomes and might expand largely due to segmental duplication in soybean. The GmCPA family underwent purifying selection rather than neutral or positive selections. The cis-element analysis and the publicly available transcriptome data indicated that GmCPAs are involved in development and various environmental adaptations, especially for salt tolerance. Based on the RNA-seq data, twelve of the chosen GmCPA genes were confirmed for their differentially expression under salt or osmotic stresses using qRT-PCR. Among them, GmCHX20a was selected due to its high induction under salt stress for the exploration of its biological function on salt responses by ectopic expressing in Arabidopsis. The results suggest that the overexpression of GmCHX20a increases the sensitivity to salt stress by altering the redox system. Overall, this study provides comprehensive insights into the CPA family in soybean and has the potential to supply new candidate genes to develop salt-tolerant soybean varieties.


Assuntos
Antiporters , Arabidopsis , Antiporters/genética , Antiporters/metabolismo , Prótons , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo , Cátions Monovalentes/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Front Bioeng Biotechnol ; 10: 962230, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36204463

RESUMO

Lead (Pb) threatens public health due to its toxicity and nonbiodegradable characteristics. It is of significance to develop a sensitive and rapid method for Pb detection. In this study, monoclonal antibodies against Pb were screened with a high affinity constant (Kaff) of 3.56 × 109 L/mol. Au nanosphere particles (AuNS) and Au nanoflower particles (AuNF) were synthesized with a diameter of 15 nm and 60 nm, respectively. The specific anti-Pb antibodies were then immobilized on AuNS and AuNF for probe development. At last, AuNS- and AuNF-based strips were successfully assembled for comparative study, which were able to effectively detect environmental Pb in 10 min. The limits of detection (LODs) were determined to be 3.91 ng/ml and 0.2 ng/ml, respectively. Thus the developed method provides a feasible solution for sensitive and rapid detection of Pb on site, which is beneficial to food safety and pollution control.

3.
Toxins (Basel) ; 13(11)2021 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-34822615

RESUMO

Aspergillus flavus poses a threat to society economy and public health due to aflatoxin production. aflN is a gene located in the aflatoxin gene cluster, but the function of AflN is undefined in Aspergillus flavus. In this study, aflN is knocked out and overexpressed to study the function of AflN. The results indicated that the loss of AflN leads to the defect of aflatoxin biosynthesis. AflN is also found to play a role in conidiation but not hyphal growth and sclerotia development. Moreover, AlfN is related to the response to environmental oxidative stress and intracellular levels of reactive oxygen species. At last, AflN is involved in the pathogenicity of Aspergillus flavus to host. These results suggested that AflN played important roles in aflatoxin biosynthesis, conidiation and reactive oxygen species generation in Aspergillus flavus, which will be helpful for the understanding of aflN function, and will be beneficial to the prevention and control of Aspergillus flavus and aflatoxins contamination.


Assuntos
Aflatoxinas/biossíntese , Aspergillus flavus/genética , Proteínas Fúngicas/genética , Aflatoxinas/genética , Aspergillus flavus/patogenicidade , Regulação Fúngica da Expressão Gênica , Família Multigênica , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
4.
Protein J ; 38(6): 675-682, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31332687

RESUMO

Thymosin beta 10 (TB10) is one of the common members among beta-thymosins. Human TB10 is reported to play a role in anti-angiogenesis and inhibition of cell migration during the tumorigenesis or metastasis of some certain cancers. Thus, it would be a potent clinical agent. In the present study, the coding sequence of TB10 was optimized based on the codon preference of Escherichia coli and cloned to pET28a (+) by chemical synthesis and molecular cloning methods. The recombinant protein was highly expressed employing E. coli expressing system and purified by a simple step of Ni2+ affinity chromatography. The TEV proteinase recognition site was inserted in the His6-tag and the target protein for easy removal of the His6-tag. To improve the biological activity of TB10, the transactivator of transcription (TAT) short peptide, a transduction domain, was added to the N-terminus of TB10. About 14.3 mg of the recombinant TB10 proteins was obtained from 1 L bacterial culture. The functional analyses demonstrated that the recombinant TB10 proteins displayed the distinct inhibition on angiogenesis by chick embryo chorioallantoic membrane assay and endothelial cell migration by wound healing assay. The TAT-fused TB10 even had stronger effects, probably due to the better transduction into the cells.


Assuntos
Proteínas Recombinantes de Fusão , Timosina , Inibidores da Angiogênese/farmacologia , Clonagem Molecular , Escherichia coli/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Timosina/isolamento & purificação , Timosina/farmacologia
5.
PLoS One ; 14(5): e0216470, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31063496

RESUMO

BACKGROUND: Human B-cell lymphoma 6 (BCL6) gene, usually coding protein of 706 amino acids, is closely associated with large B cell lymphoma. Researches showed that protein mutation or change of expression levels usually happened in the mounting non-hodgkin lymphoma (NHL). Thus BCL6 is considered to be involved in germinal center (GC)-derived lymphoma. RESULTS: The BCL61-350 gene codons were optimized for prokaryotic system. After expression of BCL61-350 in E. coli, the BCL61-350 protein was purified with Ni column. Then the BCL61-350 protein, mixing with QuickAntibody-Mouse5W adjuvant, was injected into Balb/c mice. After immunization and cell fusion, a stable cell line named 1E6A4, which can secrete anti-BCL6 antibody, was obtained. The isotype of 1E6A4 mAb was determined as IgG2a, and the affinity constant reached 5.12×1010 L/mol. Furthermore, the specificity of the mAb was determined with ELISA, western blot and immunohistochemistry. Results indicated that the 1E6A4 mAb was able to detect BCL6 specifically and sensitively. CONCLUSIONS: BCL61-350 antigen has been successfully generated with an effective and feasible method, and a highly specific antibody named 1E6A4 against BCL6 has been screened and characterized in this study, which was valuable in clinical diagnosis.


Assuntos
Anticorpos Monoclonais Murinos , Imunoglobulina G , Linfoma de Células B/diagnóstico , Linfoma de Células B/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Animais , Anticorpos Monoclonais Murinos/química , Anticorpos Monoclonais Murinos/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Centro Germinativo/patologia , Humanos , Imunoglobulina G/química , Imunoglobulina G/imunologia , Imuno-Histoquímica , Linfoma de Células B/metabolismo , Linfoma de Células B/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-bcl-6/biossíntese
6.
Mol Med Rep ; 19(4): 2953-2959, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30720089

RESUMO

Fibroblast growth factor 15 (FGF15) was previously identified to be highly expressed in the ileum and functions as an endocrine factor to regulate bile acid synthesis in the liver. FGF15 targets its receptor fibroblast growth factor receptor 4 in the liver and serves important roles in energy metabolism, including bile acid homeostasis, glucose metabolism and protein synthesis. The expression of FGF15 is known to be regulated by the transcription factor farnesoid X receptor (FXR). In the present study, reverse transcription­quantitative polymerase chain reaction was used for measuring Fgf15 expression from the animal and tissue culture experiments, and it was identified that dexamethasone, a drug widely used in anti­inflammation therapy, and a classical inducer of glucocorticoid receptor (GR)­ and pregnane X receptor (PXR)­target genes, may downregulate Fgf15 expression in the ileum. GR was identified to be highly expressed in the ileum by western blot analysis. Furthermore, it was demonstrated that the downregulation of Fgf15 by dexamethasone is due to the repression of ileal FXR activity via GR; however, not PXR, in the ileum. The present results provide insight for a better understanding of the adverse effects associated with dexamethasone therapy.


Assuntos
Fatores de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica , Mucosa Intestinal/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Dexametasona/farmacologia , Íleo/metabolismo , Masculino , Camundongos , Receptor de Pregnano X/metabolismo
7.
Genes Genomics ; 41(1): 107-111, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30264213

RESUMO

Lipoic acid synthase (LipA) plays a role in lipoic acid synthesis and potentially affects the levels of acetyl-CoA, the critical precursor of tricarboxylic acid (TCA) cycle. Considering the potential effect of LipA on TCA cycle, whether the enzyme is involved in the growth and aflatoxin B1 (AFB1) biosynthesis, the significant events in Aspergillus flavus is yet known. The study was designed to explore the role of lipA gene in A. flavus, including growth rate, conidiation, sclerotia formation, and biosynthesis of AFB1. LipA coding lipoic acid synthetase was knocked out using homologous recombination. The role of lipA gene in A. flavus morphogenesis (including colony size, conidiation, and sclerotia formation) was explored on various media, and the bio-function of lipA gene in the biosynthesis of AFB1 was analyzed by thin layer chromatography analysis. The growth was suppressed in △lipA. The formation of conidia and sclerotia was also reduced when lipA gene was deleted. Moreover, AFB1 was down-regulated in ΔlipA compared with WT controls. LipA plays a role in the development of A. flavus and AFB1 biosynthesis, contributing to the full understanding of the lipA bio-function in A. flavus.


Assuntos
Aspergillus/genética , Proteínas Fúngicas/genética , Sulfurtransferases/genética , Aspergillus/enzimologia , Aspergillus/crescimento & desenvolvimento , Proteínas Fúngicas/metabolismo , Mutação , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Sulfurtransferases/metabolismo
8.
BMC Biotechnol ; 18(1): 25, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29728076

RESUMO

BACKGROUND: Human chromogranin A (CgA) is a ~ 49 kDa secreted protein mainly from neuroendocrine cells and endocrine cells. The CgA values in the diagnosis of tumor, and in the potential role in prognostic and predictive tumor as a biomarker. RESULTS: The synthesized gene of CgA coding area was cloned and expressed as fusion protein CgA-His in procaryotic system. Then the purified CgA-His protein was mixed with QuickAntibody-Mouse5W adjuvant, and injected into mice. The CgA-His protein was also used as coating antigen to determine the antiserum titer. By screening, a stable cell line named 4E5, which can generate anti-CgA monoclonal antibody (mAb), was obtained. The isotype of 4E5 mAb was IgG2b, and the chromosome number was 102 ± 4. Anti-CgA mAb was purified from ascites fluid, and the affinity constant reached 9.23 × 109 L/mol. Furthermore, the specificity of the mAb was determined with ELISA, western blot and immunohistochemistry. Results indicated that the mAb 4E5 was able to detect chromogranin A specifically and sensitively. CONCLUSIONS: A sensitive and reliable method was successfully developed for rapid production of anti-CgA mAb for immunohistochemistry diagnosis in this study, and the current study also provides conclusive guidelines for preparation of mAbs and implements in immunohistochemistry diagnosis.


Assuntos
Anticorpos Monoclonais/biossíntese , Cromogranina A/imunologia , Neoplasias/diagnóstico , Animais , Anticorpos Monoclonais/genética , Especificidade de Anticorpos , Humanos , Imuno-Histoquímica , Camundongos Endogâmicos BALB C
9.
Environ Health Perspect ; 125(6): 067004, 2017 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-28599267

RESUMO

BACKGROUND: The potential carcinogenicity of naphthalene (NA), a ubiquitous environmental pollutant, in human respiratory tract is a subject of intense debate. Chief among the uncertainties in risk assessment for NA is whether human lung CYP2A13 and CYP2F1 can mediate NA's respiratory tract toxicity. OBJECTIVES: We aimed to assess the in vivo function of CYP2A13 and CYP2F1 in NA bioactivation and NA-induced respiratory tract toxicity in mouse models. METHODS: Rates of microsomal NA bioactivation and the effects of an anti-CYP2A antibody were determined for lung and nasal olfactory mucosa (OM) from Cyp2abfgs-null, CYP2A13-humanized, and CYP2A13/2F1-humanized mice. The extent of NA respiratory toxicity was compared among wild-type, Cyp2abfgs-null, and CYP2A13/2F1-humanized mice following inhalation exposure at an occupationally relevant dose (10 ppm for 4 hr). RESULTS: In vitro studies indicated that the NA bioactivation activities in OM and lung of the CYP2A13/2F1-humanized mice were primarily contributed by, respectively, CYP2A13 and CYP2F1. CYP2A13/2F1-humanized mice showed greater sensitivity to NA than Cyp2abfgs-null mice, with greater depletion of nonprotein sulfhydryl and occurrence of cytotoxicity (observable by routine histology) in the OM, at 2 or 20 hr after termination of NA exposure, in humanized mice. Focal, rather than gross, lung toxicity was observed in Cyp2abfgs-null and CYP2A13/2F1-humanized mice; however, the extent of NA-induced lung injury (shown as volume fraction of damaged cells) was significantly greater in the terminal bronchioles of CYP2A13/2F1-humanized mice than in Cyp2abfgs-null mice. CONCLUSION: CYP2F1 is an active enzyme. Both CYP2A13 and CYP2F1 are active toward NA in the CYP2A13/2F1-humanized mice, where they play significant roles in NA-induced respiratory tract toxicity. https://doi.org/10.1289/EHP844.


Assuntos
Família 2 do Citocromo P450/metabolismo , Naftalenos/toxicidade , Testes de Toxicidade , Animais , Carcinógenos/toxicidade , Humanos , Pulmão/metabolismo , Camundongos , Camundongos Knockout , Mucosa Nasal/metabolismo
10.
Biochimie ; 138: 13-19, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28408247

RESUMO

Parathyroid hormone-related protein (PTHrP), a ubiquitously expressed protein, is composed of four functional domains including N-terminus, mid region, nuclear localization signal (NLS) and C-terminus. Under the direction of NLS, PTHrP can enter cell nucleus from cytoplasm and stimulate mitogenesis. Although PTHrP is considered to have important developmental roles, the role of PTHrP NLS and C-terminus in developmental process remains unknown, especially in T-cell development. Here, we used a knock-in mouse model, which expresses a truncated form of PTHrP missing the NLS (87-107) and C-terminus (108-139) of the protein, to examine the role of PTHrP NLS and C-terminus in T-cell development. Our results showed that the truncated PTHrP (1-84) led to abnormal subpopulations, impaired proliferation and increased apoptosis in the thymus, indicating that PTHrP is involved in the development of T cells, and the NLS and C-terminus part is necessary for the normal role of PTHrP in T-cell development.


Assuntos
Sequência de Aminoácidos , Sinais de Localização Nuclear , Proteína Relacionada ao Hormônio Paratireóideo/genética , Deleção de Sequência , Linfócitos T/metabolismo , Animais , Apoptose , Proliferação de Células , Camundongos , Modelos Animais , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Linfócitos T/fisiologia
11.
Drug Metab Dispos ; 42(8): 1341-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24907355

RESUMO

CYP2A13, CYP2B6, and CYP2F1 are neighboring cytochrome P450 genes on human chromosome 19, and the enzymes that they encode overlap in substrate specificity. A CYP2A13/2B6/2F1-transgenic mouse, in which CYP2A13 and 2F1 are both expressed in the respiratory tract and CYP2B6 is expressed in the liver, was recently generated. We generated a CYP2A13 (only) transgenic mouse so that the specific activity of CYP2A13 can be determined. The CYP2B6 and CYP2F1 genes in the CYP2A13/2B6/2F1 genomic clone were inactivated via genetic manipulations, and CYP2A13 was kept intact. A CYP2A13 (only) transgenic (2A13-TG) mouse was generated using the engineered construct and then characterized to confirm transgene integrity and determine copy numbers. The 2A13-TG mice were normal in gross morphology, development, and fertility. As in the CYP2A13/2B6/2F1-transgenic mouse, CYP2A13 expression in the 2A13-TG mouse was limited to the respiratory tract; in contrast, CYP2B6 and 2F1 proteins were not detected. Additional studies using the CYP2A13-humanized (2A13-TG/Cyp2abfgs-null) mouse produced by intercrossing between 2A13-TG and Cyp2abfgs-null mice confirmed that the transgenic CYP2A13 is active in the bioactivation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a lung procarcinogen. The 2A13-TG mouse should be valuable for assessing specific roles of human CYP2A13 in xenobiotic toxicity in the respiratory tract.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Camundongos Transgênicos/genética , Camundongos Transgênicos/metabolismo , Animais , Modelos Animais de Doenças , Dosagem de Genes/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sistema Respiratório/enzimologia , Sistema Respiratório/metabolismo
12.
Antioxid Redox Signal ; 21(1): 33-45, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24295239

RESUMO

AIM: Reactive oxygen species (ROS) plays important roles in aging. However, the specific mechanisms for intracellular ROS accumulation, especially during aging, remain elusive. RESULTS: We have reported that Fas-associated protein with death domain (FADD) phosphorylation abolishes the recruitment of phosphatase type 2A C subunit (PP2Ac) to protein kinase C (PKC)ßII, which specifically regulates mitochondrial ROS generation by p66shc. Here, we have studied the role of FADD phosphorylation in an FADD constitutive-phosphorylation mutation (FADD-D) mouse model. In FADD-D mice, the constitutive FADD phosphorylation led to ROS accumulation (hydrogen peroxide [H2O2]), in a process that was dependent on PKCß and accompanied by increased PKCß and p66shc phosphorylation, impaired mitochondrial integrity, and enhanced sensitivity to oxidative stress-mediated apoptosis. Moreover, FADD-D mice exhibited premature aging-like phenotypes, including DNA damage, cellular senescence, and shortened lifespan. In addition, we demonstrate that FADD phosphorylation and the recruitment of PP2A and FADD to PKCß are induced responses to oxidative stress, and that the extent of FADD phosphorylation in wild-type mice was augmented during aging, accompanied by impairment of the interaction between PKCß and PP2A. INNOVATION: The present study first addresses the role of FADD phosphorylation in aging through controlling mitochondrial ROS specifically generated by PKCß. CONCLUSION: These data identify that FADD phosphorylation is critical for the PKCß-p66shc signaling route to generate H2O2 and to implicate enhanced FADD phosphorylation as a primary cause of ROS accumulation during aging.


Assuntos
Envelhecimento/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Proliferação de Células/fisiologia , Células Cultivadas , Imuno-Histoquímica , Imunoprecipitação , Marcação In Situ das Extremidades Cortadas , Masculino , Camundongos , Fosforilação , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Pharmacol Exp Ther ; 347(3): 746-54, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24045421

RESUMO

Nicotine metabolism is believed to affect not only nicotine's pharmacological effects but also nicotine addiction. As a key step toward testing this hypothesis, we have studied nicotine metabolism and nicotine's pharmacological and behavioral effects in a novel knockout mouse model [named Cyp2a(4/5)bgs-null] lacking a number of cytochrome P450 genes known to be or possibly involved in nicotine metabolism, including two Cyp2a and all Cyp2b genes. We found that, compared with wild-type mice, the Cyp2a(4/5)bgs-null mice showed >90% decreases in hepatic microsomal nicotine oxidase activity in vitro, and in rates of systemic nicotine clearance in vivo. Further comparisons of nicotine metabolism between Cyp2a(4/5)bgs-null and Cyp2a5-null mice revealed significant roles of both CYP2A5 and CYP2B enzymes in nicotine clearance. Compared with the behavioral responses in wild-type mice, the decreases in nicotine metabolism in the Cyp2a(4/5)bgs-null mice led to prolonged nicotine-induced acute pharmacological effects, in that null mice showed enhanced nicotine hypothermia and antinociception. Furthermore, we found that the Cyp2a(4/5)bgs-null mice developed a preference for nicotine in a conditioned place preference test, a commonly used test of nicotine's rewarding effects, at a nicotine dose that was 4-fold lower than what was required by wild-type mice. Thus, CYP2A/2B-catalyzed nicotine clearance affects nicotine's behavioral response as well as its acute pharmacological effects in mice. This result provides direct experimental support of the findings of pharmacogenetic studies that suggest linkage between rates of nicotine metabolism and smoking behavior in humans.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Comportamento Animal/efeitos dos fármacos , Nicotina/metabolismo , Nicotina/farmacologia , Agonistas Nicotínicos/metabolismo , Agonistas Nicotínicos/farmacologia , Esteroide Hidroxilases/genética , Animais , Temperatura Corporal/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Citocromo P-450 CYP2A6 , Família 2 do Citocromo P450 , Meia-Vida , Imersão , Masculino , Camundongos , Camundongos Knockout , Medição da Dor/efeitos dos fármacos , Tempo de Reação/efeitos dos fármacos , Recompensa
14.
Drug Metab Dispos ; 41(2): 529-35, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23160819

RESUMO

The study was originally designed to test the hypothesis that the compensatory increase in intestinal P450 (cytochrome P450) expression in the intestinal epithelium-specific P450 reductase (CPR) knockout (IE-Cpr-null) mice was attributable to decreased metabolism of putative P450 inducers present in the diet. Thus, we determined the impact of a dietary change from regular rodent chow to a synthetic diet devoid of phytochemicals on the expression of P450 enzymes in the small intestine (SI) and liver of wild-type (WT) and IE-Cpr-null mice. The dietary change diminished expression of CYP1A, 2B, 2C, and 3A in SI and CYP2B, 2C, and 3A in liver of both WT and IE-Cpr-null mice. However, the compensatory increase in SI P450 expression still occurred in IE-Cpr-null, compared with WT, mice, on the synthetic diet. The diet change-induced decrease in P450 expression was accompanied by decreases in microsomal midazolam-hydroxylase activity in vitro and first-pass clearance of midazolam in vivo in WT mice. Further studies showed that the dietary change, but not Cpr deletion, caused large decreases in bile acid (BA) levels in plasma, liver, SI, and intestinal content and that treatment of WT mice on the synthetic diet with GW4064, a farnesoid-X-receptor agonist, restored the levels of CYP3A expression in both liver and SI to those seen in mice fed with regular chow. Taken together, these results highlight the vital role of diet in maintaining adequate expression of major drug-metabolizing P450s and their associated drug-metabolizing activities in the digestive tract and suggest potential involvement of BA signaling in the regulatory mechanisms.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Intestinos/enzimologia , Midazolam/farmacocinética , Ração Animal , Animais , Ácidos e Sais Biliares/sangue , Biotransformação , Feminino , Hidroxilação , Intestinos/efeitos dos fármacos , Isoenzimas , Isoxazóis/farmacologia , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microssomos Hepáticos/enzimologia , Midazolam/administração & dosagem , Midazolam/sangue , NADPH-Ferri-Hemoproteína Redutase/deficiência , NADPH-Ferri-Hemoproteína Redutase/genética , Receptores Citoplasmáticos e Nucleares/agonistas , Receptores Citoplasmáticos e Nucleares/metabolismo , Especificidade por Substrato
15.
PLoS One ; 7(5): e37132, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22590653

RESUMO

BACKGROUND: Blood vessels in tumors express higher level of aminopeptidase N (APN) than normal tissues. Evidence suggests that the CNGRC motif is an APN ligand which targets tumor vasculature. Increased expression of APN in tumor vascular endothelium, therefore, offers an opportunity for targeted delivery of NGR peptide-linked drugs to tumors. METHODS/PRINCIPAL FINDINGS: To determine whether an additional cyclic CNGRC sequence could improve endothelial cell homing and antitumor effect, human plasminogen kringle 5 (hPK5) was modified genetically to introduce a CNGRC motif (NGR-hPK5) and was subsequently expressed in yeast. The biological activity of NGR-hPK5 was assessed and compared with that of wild-type hPK5, in vitro and in vivo. NGR-hPK5 showed more potent antiangiogenic activity than wild-type hPK5: the former had a stronger inhibitory effect on proliferation, migration and cord formation of vascular endothelial cells, and produced a stronger antiangiogenic response in the CAM assay. To evaluate the tumor-targeting ability, both wild-type hPK5 and NGR-hPK5 were (99 m)Tc-labeled, for tracking biodistribution in the in vivo tumor model. By planar imaging and biodistribution analyses of major organs, NGR-hPK5 was found localized to tumor tissues at a higher level than wild-type hPK5 (approximately 3-fold). Finally, the effects of wild-type hPK5 and NGR-modified hPK5 on tumor growth were investigated in two tumor model systems. NGR modification improved tumor localization and, as a consequence, effectively inhibited the growth of mouse Lewis lung carcinoma (LLC) and human colorectal adenocarcinoma (Colo 205) cells in tumor-bearing mice. CONCLUSIONS/SIGNIFICANCE: These studies indicated that the addition of an APN targeting peptide NGR sequence could improve the ability of hPK5 to inhibit angiogenesis and tumor growth.


Assuntos
Inibidores da Angiogênese/farmacocinética , Neoplasias/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Oligopeptídeos/farmacocinética , Fragmentos de Peptídeos/farmacocinética , Plasminogênio/farmacocinética , Motivos de Aminoácidos , Inibidores da Angiogênese/farmacologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Embrião de Galinha , Feminino , Humanos , Camundongos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Oligopeptídeos/genética , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/farmacologia , Plasminogênio/genética , Plasminogênio/farmacologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacocinética , Proteínas Recombinantes de Fusão/farmacologia
16.
J Biol Chem ; 287(21): 17777-17788, 2012 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-22453923

RESUMO

NADPH-cytochrome P450 reductase (POR) is essential for the functioning of microsomal cytochrome P450 (P450) monooxygenases and heme oxygenases. The biological roles of the POR-dependent enzymes in the intestine have not been defined, despite the wealth of knowledge on the biochemical properties of the various oxygenases. In this study, cDNA microarray analysis revealed significant changes in gene expression in enterocytes isolated from the small intestine of intestinal epithelium-specific Por knock-out (named IE-Cpr-null) mice compared with that observed in wild-type (WT) littermates. Gene ontology analyses revealed significant changes in terms related to P450s, transporters, cholesterol biosynthesis, and, unexpectedly, antigen presentation/processing. The genomic changes were confirmed at either mRNA or protein level for selected genes, including those of the major histocompatibility complex class II (MHC II). Cholesterol biosynthetic activity was greatly reduced in the enterocytes of the IE-Cpr-null mice, as evidenced by the accumulation of the lanosterol metabolite, 24-dihydrolanosterol. However, no differences in either circulating or enterocyte cholesterol levels were observed between IE-Cpr-null and WT mice. Interestingly, the levels of the cholesterol precursor farnesyl pyrophosphate and its derivative geranylgeranyl pyrophosphate were also increased in the enterocytes of the IE-Cpr-null mice. Furthermore, the expression of STAT1 (signal transducer and activator of transcription 1), a downstream target of geranylgeranyl pyrophosphate signaling, was enhanced. STAT1 is an activator of CIITA, the class II transactivator for MHC II expression; CIITA expression was concomitantly increased in IE-Cpr-null mice. Overall, these findings provide a novel and mechanistic link between POR-dependent enzymes and the expression of MHC II genes in the small intestine.


Assuntos
Regulação da Expressão Gênica/fisiologia , Genes MHC da Classe II/fisiologia , Antígenos de Histocompatibilidade Classe II/biossíntese , Intestino Delgado/metabolismo , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Animais , Sequência de Bases , Antígenos de Histocompatibilidade Classe II/genética , Lanosterol/genética , Lanosterol/metabolismo , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , NADPH-Ferri-Hemoproteína Redutase/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Transativadores/genética , Transativadores/metabolismo
17.
Cell Biol Int ; 34(1): 49-52, 2009 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-19947935

RESUMO

Cellular adenosine accumulates under stress conditions. Few papers on adenosine are concerned with its function in the cell cycle. The cell cycle is the essential mechanism by which all living things reproduce and the target machinery when cells encounter stresses, so it is necessary to examine the relationship between adenosine and the cell cycle. In the present study, adenosine was found to induce G-2/M cell-cycle arrest. Furthermore, adenosine was found to modulate the expression of some important proteins in the cell cycle, such as cyclin B and p21, and to inhibit the transition of metaphase to anaphase in mitosis.


Assuntos
Adenosina/farmacologia , Mitose , Anáfase , Divisão Celular , Linhagem Celular , Ciclina B/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citometria de Fluxo , Fase G2 , Humanos , Metáfase , Microscopia de Fluorescência
18.
Protein Expr Purif ; 51(1): 102-9, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16919473

RESUMO

Because of its stringent sequence specificity, tobacco etch virus (TEV) protease emerges as a useful reagent with wide application in the cleavage of recombinant fusion proteins. However, the solubility of TEV protease expressed in Escherichia coli is extremely low. In the present study, we introduced a more efficient system to improve and facilitate the soluble production of TEV protease in E. coli. Optimal expression of soluble His6-TEV was achieved by examining the contribution of chaperone co-expression and lower temperature fermentation. When further purified by Ni(2+) affinity chromatography, 65mg of His6-TEV was isolated with purity over 95% from 1L of culture. The enzyme activity of His6-TEV was generally characterized by using GST-EGFP and His6-L-TNF fusion protein as substrates, which contained a TEV cleavage site between two moieties.


Assuntos
Clonagem Molecular/métodos , Endopeptidases/biossíntese , Endopeptidases/isolamento & purificação , Chaperonina 10/biossíntese , Chaperonina 60/biossíntese , Cromatografia de Afinidade , Endopeptidases/metabolismo , Indução Enzimática , Escherichia coli/enzimologia , Proteínas de Escherichia coli/biossíntese , Histidina/química , Isopropiltiogalactosídeo/farmacologia , Chaperonas Moleculares/farmacologia , Oligopeptídeos/química , Peptidilprolil Isomerase/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Solubilidade , Temperatura
19.
Cancer Biol Ther ; 4(8): 840-5, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16210914

RESUMO

The growth of tumor is angiogenesis-dependent and it often contains hypoxia and necrotic areas. Salmonella VNP20009 could target and replicate in hypoxia and necrotic areas within tumor and induce antitumor effect. Angiogenesis inhibitor endostatin could reduce tumor angiogenesis and inhibit its growth. However, in the phase I trials of VNP20009 and endostatin at the maximum-tolerated dose, no antitumor effects for bacteria therapy and minor therapeutic effects for endostatin treatment were seen. The ineffectiveness of these agents in clinical trials suggests that the combination of these agents with synergic modalities might be necessary. Here we described antitumor effects mediated by the combination of VNP20009 with recombinant human endostatin in B16F10 murine melanoma model with the aim to exploit tumor-targeting of bacteria and anti-angiogenesis strategy to enhance therapeutic efficacy. Combination therapy of these agents significantly enhanced antitumor effects by inducing greater tumor growth inhibition, more severe tumor tissue necrosis as well as less blood vessel density than those induced by either of treatments. The findings suggest that the combination of tumor-targeting bacteria with angiogenesis inhibitor might be of value for the treatment of solid tumors.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Endostatinas/uso terapêutico , Melanoma Experimental/tratamento farmacológico , Vacinas Atenuadas/uso terapêutico , Animais , Vacinas Bacterianas , Terapia Combinada , Melanoma Experimental/química , Camundongos , Fator A de Crescimento do Endotélio Vascular/análise
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