Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
J Cell Biochem ; 115(1): 189-98, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24038094

RESUMEN

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that play a critical role to activate immune response. They may be targeted for immunomodulation by microbes, including probiotics. In this study, chicken bone marrow dendrite cells (chi-BMDCs) were stimulated with lipopolysachride (LPS), Saccharomyces boulardii (Sb), Bacillus subtilis B10 (Bs), co-culture of Sb + Bs and phosphate buffer saline (PBS) as a control group (Ctr) at 3, 6, and 12 h intervals. Results revealed that treatment groups modulated the phenotype and biological functions of chi-BMDCs. Scan electron microscopy showed attachment of probiotics on the surface of chi-BMDCs. Additionally transmission electron microscopy (TEM) revealed efficiently engulfing and degradation of probiotics. Gene expression levels of MHC-II, CD40, CD80 and CD86 up-regulated in stimulated groups. Furthermore, toll-like receptors TLR1, TLR2, TLR4, and chicken specific TLR15 expressions were improved and downstream associated factors MyD88, TRAF6, TAB1, and NFκ-B mRNA levels increased in all treatment groups as compared to control. Surprisingly, NFκ-B response was noted significant higher in LPS treatment among all groups. Moreover, IL-1ß, IL-17, IL-4, TGF-ß, and IL-10 production levels were found higher, and lower concentration of INF-γ and IL-8 were observed in Sb, Bs, and Sb + Bs treatment groups. In contrast, LPS groups showed prominent increase in IL-12, INF-γ, and IL-8 concentration levels as compared to control group. Altogether, these results emphasize a potentially important role of Saccharomyces boulardii and Bacillus subtilis B10 in modulating immunological functions of chi-BMDCs by targeting specific toll like receptors (TLRs) and associated factors. The role of probiotics on chi-BMDCs functionality in a non-mammalian species have been presented for the first time.


Asunto(s)
Bacillus subtilis , Células de la Médula Ósea/inmunología , Células Dendríticas/inmunología , Células Dendríticas/microbiología , Probióticos/farmacología , Saccharomyces , Receptores Toll-Like/metabolismo , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/microbiología , Células Cultivadas , Quimiocinas/metabolismo , Pollos , Citocinas/metabolismo , Células Dendríticas/efectos de los fármacos , Regulación de la Expresión Génica , Lipopolisacáridos/farmacología , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Transducción de Señal
2.
Arch Microbiol ; 195(5): 349-56, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23455449

RESUMEN

Depending on the microenvironment, macrophages can acquire distinct functional phenotypes, referred to as classically activated M1 and M2. M1 macrophages are considered potent effector cells that kill intracellular pathogens, and M2 macrophages promote the resolution of wound healing. In this study, we are interested to know whether probiotic Bacillus amyloliquefaciens (Ba) can induce macrophages polarization. Real-time fluorescence PCR analysis demonstrated that the expression of IL-1ß, iNOS, TNF-α and IL-6 genes for M1 macrophages was significantly increased at 1.5 h after probiotic Ba treatment compared to the probiotic Ba-free treatment (P < 0.01), whereas the expression of M2 macrophage marker genes (Arg1, Fizz1, MR, Ym1) was decreased (P < 0.05). Furthermore, the phagocytic activity was dramatically increased in the Ba-treated BMDMs using a FITC-dextran endocytosis assay. Together, these findings indicated that probiotic Ba facilitated polarization of M1 macrophages and enhanced its phagocytic capacity. The results expanded our knowledge about probiotic function-involved macrophage polarization.


Asunto(s)
Bacillus , Activación de Macrófagos , Macrófagos/inmunología , Probióticos/administración & dosificación , Transcriptoma , Animales , Bacillus/clasificación , Bacillus/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/metabolismo
3.
Pharm Biol ; 49(3): 256-61, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20979538

RESUMEN

CONTEXT: Scutellaria baicalensis Georgi (Labiatae) (SbG), one of the fifty fundamental herbs of Chinese herbology, has been reported to have anti-asthmatic, antifungal, antioxidative, and anti-inflammatory activities. OBJECTIVE: This study was designed to determine the protective effects of the extract of SbG against the acrolein-induced oxidative stress in cultured human umbilical vein endothelial cells (HUVEC). MATERIALS AND METHODS: The MTT reduction assay was employed to determine cell viability. The total cellular glutathione (GSH) level was detected using a colorimetric GSH assay kit. Cellular GSH production was conducted by detecting the mRNA expression levels of γ-glutamylcysteine ligase catalytic subunit and modifier subunit. RESULTS: Concentration-dependent cytotoxic effects of acrolein were observed while SbG could effectively protect the acrolein-induced oxidative damage. The protective mechanism was investigated, showing that the increased GSH content in the SbG-incubated HUVE cells was associated with the protective effects of SbG-treated cells. Further RT-PCR data confirmed the elevated mRNA expressions of GSH synthesis enzymes. DISCUSSION AND CONCLUSION: The current study strongly indicated that SbG could be a potential antioxidant against oxidative stress in treating cardiovascular diseases.


Asunto(s)
Acroleína/antagonistas & inhibidores , Acroleína/toxicidad , Endotelio Vascular/metabolismo , Estrés Oxidativo/fisiología , Extractos Vegetales/farmacología , Venas Umbilicales/metabolismo , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Humanos , Estrés Oxidativo/efectos de los fármacos , Sustancias Protectoras/farmacología , Scutellaria baicalensis , Venas Umbilicales/citología , Venas Umbilicales/efectos de los fármacos
4.
Front Vet Sci ; 8: 679368, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34150896

RESUMEN

The aim of this study was to evaluate the dietary effects of Bacillus amyloliquefaciens SC06 (SC06) instead of antibiotics on the growth performance, intestinal health, and intestinal microbiota of broilers. A total of 360 30-day-old Lingnan yellow broilers were randomly allocated into two groups with six replicates per group (30 birds per replicate). The broilers were fed either a non-supplemented diet or a diet supplemented with 108 colony-forming units lyophilized SC06 per kilogram feed for 30 days. Results showed that SC06 supplementation had no effect on the growth performance compared with that of the control group. SC06 treatment significantly (P <0.05) increased the total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) activity in the liver, and the activities of trypsin, α-amylase (AMS), and Na+K+-ATPase in the ileum, whereas it decreased (P < 0.05) lipase, gamma glutamyl transpeptidase (γ-GT), and maltase activities in the ileum. Meanwhile, SC06 treatment also improved the immune function indicated by the significantly (P < 0.05) increased anti-inflammatory cytokine [interleukin (IL)-10] level and the decreased (P < 0.05) pro-inflammatory cytokine [IL-6 and tumor necrosis factor (TNF)-α] levels in the ileum. Furthermore, we also found that SC06 enhanced the intestinal epithelial intercellular integrity (tight junction and adhesion belt) in the ileum. Microbial analysis showed that SC06 mainly increased the alpha diversity indices in the jejunum, ileum, and cecum. SC06 treatment also significantly (P < 0.05) increased the abundances of Bacteroidetes, Bacteroidales, Bacteroides, Fusobacteria, Clostridiaceae, and Veillonellaceae in the cecum and simultaneously decreased the abundances of Planococcaceae in the duodenum, Microbacteriaceae in the jejunum, and Lachnospiraceae, [Ruminococcus] and Ruminococcus in cecum. In conclusion, these results suggested that B. amyloliquefaciens instead of antibiotics showed a potential beneficial effect on the intestinal health of broilers.

5.
Am J Cancer Res ; 11(5): 1895-1912, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34094660

RESUMEN

As an important trace element, iron plays an essential role in many biology processes like cell proliferation, metabolism, and mitochondrial function. However, the disruption of iron homeostasis tends to cells death and human diseases due to it servers as mediator to promote the production of reactive oxygen species (ROS). In this review, first we introduced the mechanism of complex iron-mediated ROS involved in apoptosis, necroptosis, ferroptosis and pyroptosis. Next, we discussed the controversial role of excess iron and iron deficiency in tumor. Finally, we discussed the anti-cancer effects of iron on both sides, and novel iron-related strategies. This review outlined the mechanisms and regulation of iron homeostasis and iron-mediated ROS in tumors, and discussed the iron-related treatments.

6.
Fish Shellfish Immunol ; 28(1): 49-55, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19800009

RESUMEN

The protective efficacy of oral administration of VP28 using Bacillus subtilis as vehicles (rVP28-bs) in shrimp, Fenneropenaeus chinensis, upon challenge with white spot syndrome virus (WSSV) was investigated. The calculated relative percent survival (RPS) value of rVP28-bs fed shrimp was 83.3% when challenged on the 14th day post-administration, which is significantly higher (p < 0.001) than that of the group administered recombinant Escherichia coli over-expressing rVP28 (rVP28-e21). After immunization, activities of phenoloxidase (PO), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS) in hemolymph were analyzed. It was found that the supplementation of rVP28-bs into shrimp food pellets resulted in the most pronounced increase of iNOS activity (p < 0.001), but had the least influence on activities of PO and SOD. Besides, in the shrimp orally administered with rVP28-bs, the caspase-3 activity was one-fifth that of the control, though the signs of apoptosis (chromatin margination, nuclear fragmentation and apoptotic bodies) could not be observed by transmission electron microscope (TEM). These results suggest that by oral delivery of rVP28-bs, shrimp showed significant resistance to WSSV and an effect on the innate immune system of shrimp. The remarkably enhanced level of iNOS after rVP28-bs administration might be responsible for antiviral defense in shrimp.


Asunto(s)
Penaeidae/inmunología , Virus del Síndrome de la Mancha Blanca 1/inmunología , Animales , Apoptosis/inmunología , Bacillus subtilis/virología , Caspasa 3/metabolismo , Inmunidad Innata/inmunología , Monofenol Monooxigenasa/metabolismo , Óxido Nítrico Sintasa/metabolismo , Penaeidae/enzimología , Penaeidae/virología , Superóxido Dismutasa/metabolismo
7.
Biotechnol Lett ; 32(7): 963-7, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20229062

RESUMEN

To elucidate the effects of C-terminal domains of LicMB (mature lichenase from Clostridium thermocellum) and terminal residues of LicMB-CD (catalytic domain of LicMB) on the properties of lichenase, a series of truncated genes were constructed and expressed in E. coli. The Thr-Pro box had a positive effect while the dockerin domain had a negative impact on the properties of LicMB. The N-terminal 10-25th and C-terminal 1-9th residues of LicMB-CD were necessary to retain high thermostability while the N-terminal 1-7th and C-terminal 1-3rd residues were not necessary to maintain enzymatic activity.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Clostridium thermocellum/enzimología , Glicósido Hidrolasas/química , Glicósido Hidrolasas/metabolismo , Proteínas Bacterianas/genética , Dominio Catalítico , Estabilidad de Enzimas , Escherichia coli/genética , Expresión Génica , Glicósido Hidrolasas/genética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Estabilidad Proteica , Eliminación de Secuencia , Temperatura
8.
Biotechnol Lett ; 31(7): 991-7, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19277476

RESUMEN

K88 (F4) fimbrial adhesin, FaeG, was expressed extracellularly in Lactococcus lactis using a nisin-controlled gene expression system. The antibody response and protective efficacy of the recombinant bacteria (L. lactis [spNZ8048-faeG]) against live enterotoxigenic E. coli (ETEC) C(83549) challenge were evaluated in ICR mice. Mice vaccinated with L. lactis [spNZ8048-faeG] had a significantly increased antigen-specific IgG level in the serum and decreased mortality rate (P < 0.05) compared with the control. This indicates that oral immunization of L. lactis [spNZ8048-faeG] can induce an immune-response protection upon challenge with live ETEC in ICR mice.


Asunto(s)
Adhesinas de Escherichia coli/biosíntesis , Escherichia coli Enterotoxigénica/inmunología , Infecciones por Escherichia coli/prevención & control , Vacunas contra Escherichia coli/inmunología , Lactococcus lactis/genética , Adhesinas de Escherichia coli/genética , Adhesinas de Escherichia coli/inmunología , Administración Oral , Animales , Anticuerpos Antibacterianos/sangre , ADN Bacteriano/química , ADN Bacteriano/genética , Escherichia coli Enterotoxigénica/genética , Vacunas contra Escherichia coli/administración & dosificación , Vacunas contra Escherichia coli/genética , Inmunoglobulina G/sangre , Lactococcus lactis/inmunología , Lactococcus lactis/metabolismo , Ratones , Ratones Endogámicos ICR , Datos de Secuencia Molecular , Análisis de Secuencia de ADN , Análisis de Supervivencia
9.
J Zhejiang Univ Sci B ; 20(2): 180-192, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30666850

RESUMEN

To understand the effects of Lactobacillus rhamnosus GG (ATCC 53103) on intestinal barrier function in pre-weaning piglets under normal conditions, twenty-four newborn littermate piglets were randomly divided into two groups. Piglets in the control group were orally administered with 2 mL 0.1 g/mL sterilized skim milk while the treatment group was administered the same volume of sterilized skim milk with the addition of viable L. rhamnosus at the 1st, 3rd, and 5th days after birth. The feeding trial was conducted for 25 d. Results showed that piglets in the L. rhamnosus group exhibited increased weaning weight and average daily weight gain, whereas diarrhea incidence was decreased. The bacterial abundance and composition of cecal contents, especially Firmicutes, Bacteroidetes, and Fusobacteria, were altered by probiotic treatment. In addition, L. rhamnosus increased the jejunal permeability and promoted the immunologic barrier through regulating antimicrobial peptides, cytokines, and chemokines via Toll-like receptors. Our findings indicate that oral administration of L. rhamnosus GG to newborn piglets is beneficial for intestinal health of pre-weaning piglets by improving the biological, physical, and immunologic barriers of intestinal mucosa.


Asunto(s)
Mucosa Intestinal/inmunología , Lacticaseibacillus rhamnosus , Probióticos/administración & dosificación , Administración Oral , Animales , Animales Recién Nacidos , Citocinas/genética , Femenino , Microbioma Gastrointestinal , Inmunidad Innata , Masculino , Transducción de Señal , Porcinos , Destete
10.
J Zhejiang Univ Sci B ; 19(10): 785-795, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30269446

RESUMEN

OBJECTIVE: Salmonella enterica remains a major cause of food-borne disease in humans, and Salmonella Typhimurium (ST) contamination of poultry products is a worldwide problem. Since macrophages play an essential role in controlling Salmonella infection, the aim of this study was to evaluate the effect of glycyrrhizic acid (GA) on immune function of chicken HD11 macrophages. METHODS: Chicken HD11 macrophages were treated with GA (0, 12.5, 25, 50, 100, 200, 400, or 800 µg/ml) and lipopolysaccharide (LPS, 500 ng/ml) for 3, 6, 12, 24, or 48 h. Evaluated responses included phagocytosis, bacteria-killing, gene expression of cell surface molecules (cluster of differentiation 40 (CD40), CD80, CD83, and CD197) and antimicrobial effectors (inducible nitric oxide synthase (iNOS), NADPH oxidase-1 (NOX-1), interferon-γ (IFN-γ), LPS-induced tumor necrosis factor (TNF)-α factor (LITAF), interleukin-6 (IL-6), and IL-10), and production of nitric oxide (NO) and hydrogen peroxide (H2O2). RESULTS: GA increased the internalization of both fluorescein isothiocyanate (FITC)-dextran and ST by HD11 cells and markedly decreased the intracellular survival of ST. We found that the messenger RNA (mRNA) expression of cell surface molecules (CD40, CD80, CD83, and CD197) and cytokines (IFN-γ, IL-6, and IL-10) of HD11 cells was up-regulated following GA exposure. The expression of iNOS and NOX-1 was induced by GA and thereby the productions of NO and H2O2 in HD11 cells were enhanced. Notably, it was verified that nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathways were responsible for GA-induced synthesis of NO and IFN-γ gene expression. CONCLUSIONS: Taken together, these results suggested that GA exhibits a potent immune regulatory effect to activate chicken macrophages and enhances Salmonella-killing capacity.


Asunto(s)
Ácido Glicirrínico/farmacología , Activación de Macrófagos/efectos de los fármacos , Salmonella/efectos de los fármacos , Animales , Células Cultivadas , Pollos , FN-kappa B/fisiología , Fagocitosis/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
11.
J Zhejiang Univ Sci B ; 8(9): 686-92, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17726751

RESUMEN

The objectives of this study were to assess the potential of two photosynthetic bacteria (PSB), Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions (pH 2.0, pH 3.0 and pH 4.0 gastric juices) and in simulated small intestinal transit conditions (pH 8.0, with or without 0.3% bile salts) was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochromis nilotica, were also detected. All the treatments were determined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and correspondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference (P>0.05) among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias.


Asunto(s)
Tracto Gastrointestinal/microbiología , Viabilidad Microbiana , Rhodobacter sphaeroides/aislamiento & purificación , Rhodobacter sphaeroides/fisiología , Rhodopseudomonas/aislamiento & purificación , Rhodopseudomonas/fisiología , Tilapia/microbiología , Animales , Procesos Fototróficos , Especificidad de la Especie
12.
Mol Med Rep ; 16(4): 4151-4158, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28731127

RESUMEN

Pidotimod is a synthetic dipeptide with biological and immuno­modulatory properties. It has been widely used for treatment and prevention of recurrent respiratory infections. However, its impact on the regulation of allergic pulmonary inflammation is still not clear. In the current study, an ovalbumin (OVA)­induced allergic asthma model was used to investigate the immune­modulating effects of pidotimod on airway eosinophilia, mucus metaplasia and inflammatory factor expression compared with dexamethasone (positive control). The authors determined that treatment with pidotimod exacerbated pulmonary inflammation as demonstrated by significantly increased eosinophil infiltration, dramatically elevated immunoglobulin E production, and enhanced T helper 2 response. Moreover, treatment failed to attenuate mucus production in lung tissue, and did not reduce OVA­induced high levels of FIZZ1 and Arg1 expression in asthmatic mice. In contrast, administration of dexamethasone was efficient in alleviating allergic airway inflammation in OVA­induced asthmatic mice. These data indicated that pidotimod as an immunotherapeutic agent should be used cautiously and the effectiveness for controlling allergic asthma needs further evaluation and research.


Asunto(s)
Asma/complicaciones , Asma/tratamiento farmacológico , Hipersensibilidad/tratamiento farmacológico , Ácido Pirrolidona Carboxílico/análogos & derivados , Infecciones del Sistema Respiratorio/complicaciones , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Tiazolidinas/uso terapéutico , Animales , Arginasa/metabolismo , Asma/sangre , Asma/inmunología , Líquido del Lavado Bronquioalveolar , Diferenciación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Eosinófilos/efectos de los fármacos , Eosinófilos/patología , Femenino , Hipersensibilidad/sangre , Hipersensibilidad/complicaciones , Hipersensibilidad/patología , Inmunoglobulina E/sangre , Inmunoglobulina E/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Pulmón/patología , Metaplasia , Ratones Endogámicos C57BL , Moco/efectos de los fármacos , Moco/metabolismo , Ovalbúmina , Ácido Pirrolidona Carboxílico/farmacología , Ácido Pirrolidona Carboxílico/uso terapéutico , Infecciones del Sistema Respiratorio/sangre , Infecciones del Sistema Respiratorio/patología , Células Th2/efectos de los fármacos , Células Th2/inmunología , Tiazolidinas/farmacología
13.
Immunol Lett ; 105(1): 68-76, 2006 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-16600384

RESUMEN

The effectiveness of oral, mock-, and immersion vaccination was investigated against white spot syndrome virus (WSSV) in crayfish. The most exposed WSSV envelope proteins VP19 and VP28 were used in different compositions and with different modes of applications. In experiment 1 crayfish were fed recombinant protein coated food pellets for 25 days, in experiment 2 the purified proteins were directly injected to them followed by one booster dose on 5th day and in experiment 3 the crayfish were left immersed in vaccines for 7 h. Experimental crayfish were challenged on 3rd and 21st days after last vaccination. The overall result showed that VP28 group has lowest cumulative mortality percentage accounting 39.6% at 3rd day and 39.83% at 21st day when injected and it was 43.2% and 49% when fed orally and 46.3% and 46.5% when immersed at 3rd and 21st days, respectively (p<0.05). In VP19 and VP28 (50:50) mixture, mock vaccination showed better performance (36.5%) over immersion (53%) and oral vaccination (53.2%) when challenged on 3rd day and mock vaccination (36.50%) followed by oral (51%) and immersion vaccination (56.5%) on 21st day as well. The VP19 recombinant mock vaccination group performed better (52.91% of 3rd day and 56.46% of 21st day) than oral (76% of 3rd day and 82% of 21st day) and immersion (83% of 3rd day and 86.3% of 21st day) vaccine groups. All the experimental groups except VP19 were significantly different (p<0.05) from the control groups. A positive cumulative effect was observed when VP28 was mixed with VP19 in equal proportion in all the experimental trials, which shows the effectiveness of VP19 as a vaccine component too. In the present trial on the basis of cumulative mortality percentage it is found that mock-vaccination group is more effective than the oral vaccination and immersion vaccination. It also suggests that specific memory exists in crayfish and the effects of VP28 are significant. The effect of VP19 along with VP28 has also shown significant effect against WSSV.


Asunto(s)
Astacoidea/inmunología , Astacoidea/virología , Vacunas Virales/farmacología , Virus del Síndrome de la Mancha Blanca 1/inmunología , Animales , Secuencia de Bases , Clonación Molecular , ADN Viral/genética , Genes Virales , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/farmacología , Vacunas Virales/administración & dosificación , Vacunas Virales/genética , Virosis/inmunología , Virosis/prevención & control , Virosis/virología , Virus del Síndrome de la Mancha Blanca 1/genética , Virus del Síndrome de la Mancha Blanca 1/patogenicidad
14.
Biotechnol Adv ; 24(3): 285-95, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16380225

RESUMEN

Lactic acid bacteria are widely used in industrial fermentation. The potential use of these bacteria as homologous and heterologous protein expression hosts has been investigated extensively. The NIsin-Controlled gene Expression system (the NICE system) is an efficient and promising gene expression system based on the autoregulation mechanism of nisin biosynthesis in the Lactococcus lactis. In the NICE system, the membrane-located histidine kinase NisK senses the inducing signal nisin and autophosphorylates, then transfers phosphorous group to intracellular response regulator protein NisR which activates nisA promoter to express the downstream gene(s). The NICE system allows regulated overproduction of a variety of interest proteins by several Gram-positive bacteria, especially L. lactis. The essential elements for system construction, its application for expression of some biotechnologically important proteins and further improvements of this system are discussed.


Asunto(s)
Regulación Bacteriana de la Expresión Génica , Técnicas Genéticas , Nisina/genética , Expresión Génica , Genes Bacterianos/genética , Vectores Genéticos/genética
15.
Peptides ; 27(9): 2350-9, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16675061

RESUMEN

Apidaecins (apidaecin-type peptides) refer to a series of small, proline-rich (Pro-rich), 18- to 20-residue peptides produced by insects. They are the largest group of Pro-rich antimicrobial peptides (AMPs) known to date. Structurally, apidaecins consist of two regions, the conserved (constant) region, responsible for the general antibacterial capacity, and the variable region, responsible for the antibacterial spectrum. The small, gene-encoded and unmodified apidaecins are predominantly active against many gram-negative bacteria by special antibacterial mechanisms. The mechanism of action by which apidaecins kill bacteria involves an initial non-specific binding of the peptides to an outer membrane (OM) component. This binding is followed by invasion of the periplasmic space, and by a specific and essentially irreversible combination with a receptor/docking molecule that may be a component of a permease-type transporter system on inner membrane (IM). In the final step, the peptide is translocated into the interior of the cell where it meets its ultimate target. Evidence that apidaecins are non-toxic for human and animal cells is a prerequisite for using them as novel antibiotic drugs. This review presents the biodiversity, structure-function relationships, and mechanism of action of apidaecins.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Secuencia de Aminoácidos , Animales , Antibacterianos/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Humanos , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Modelos Biológicos , Datos de Secuencia Molecular , Relación Estructura-Actividad
16.
FEMS Microbiol Lett ; 261(2): 224-30, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16907724

RESUMEN

A chimeric gene, Glu-Xyl, encoding Bacillus amyloliquefaciens glucanase (Glu, 24.4 kDa) and Bacillus subtilis xylanase (Xyl, 21.2 kDa), was constructed via end-to-end fusion and expressed successfully in Escherichia coli. The purified fusion protein (46.1 kDa) exhibited both glucanase and xylanase activities. Compared with parental enzymes, the Glu moiety was characterized by kinetic parameters of decreased K(m) (0.66-fold) and increased K(cat) (2.75-fold), whereas the Xyl moiety had an increased K(m) (1.37-fold) and decreased K(cat) (0.79-fold). These indicate a 3.15-fold net increase and a 31% decrease in catalytic efficiency (K(cat)/K(m)) of the Glu and Xyl moieties. Activities and stabilities of both moieties at 40-90 degrees C or pH 3.0-10.0 were compared with those of the parental enzymes. Despite some variations, common optima were 40 degrees C and pH 9.0 for the Glu moiety and parent, and 50-60 degrees C and pH 9.0 for the Xyl counterparts. Thus, the fusion enzyme Glu-Xyl was bifunctional, with greatly enhanced glucanase activity associated with a decrease in xylanase activity.


Asunto(s)
Bacillus subtilis/enzimología , Bacillus/enzimología , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo , Fusión Artificial Génica , Bacillus/genética , Bacillus subtilis/genética , Secuencia de Bases , Cromatografía , Clonación Molecular/métodos , Escherichia coli/genética , Glicósido Hidrolasas/química , Glicósido Hidrolasas/aislamiento & purificación , Cinética , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión/química , Xilanos/metabolismo , beta-Glucanos/metabolismo
17.
J Trace Elem Med Biol ; 20(2): 83-7, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16785047

RESUMEN

Thirty-two barrows (Duroc x Landrace x Yorkshire) were randomly divided into four groups, each of which included eight pigs. The groups received the same basal diet supplemented with 0, 100, 250 and 400mg/kg fluoride, respectively. The malondialdehyde (MDA) and glutathione (GSH) levels, antioxidant enzymes activities and zinc/copper superoxide dismutase (Cu/Zn SOD) mRNA content in the liver were determined to evaluate the fluoride hepatic intoxication. Results showed the increased lipid peroxides (LPO) level and the reduced GSH content, along with a concomitant decrease in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px). Moreover, the level of hepatic Cu/Zn SOD mRNA was also significantly reduced. We suggest the mechanism of fluoride injuring the liver as follows: fluoride causes a decrease in Cu/Zn SOD mRNA and the reduced activities of antioxidant enzymes, leads to the declined ability of scavenging free radicals with excessive production of LPO, which seriously damages the hepatic structure and function.


Asunto(s)
Antioxidantes/farmacología , Fluoruros/farmacología , Hígado/enzimología , Superóxido Dismutasa/metabolismo , Transcripción Genética , Animales , Catalasa/genética , Catalasa/metabolismo , Regulación Enzimológica de la Expresión Génica , Glutatión/genética , Glutatión/metabolismo , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Peroxidación de Lípido , Masculino , Malondialdehído/metabolismo , Distribución Aleatoria , Superóxido Dismutasa/genética , Porcinos
18.
Dis Aquat Organ ; 71(2): 175-8, 2006 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-16956066

RESUMEN

The effect of hyperthermia on the development of white spot syndrome virus (WSSV) in the crayfish Procambarus clarkii was studied by competitive PCR. Crayfish were exposed to different temperatures (24 +/- 1 and 32 +/- 1 degrees C) after WSSV injection. No mortality was observed when crayfish were held at 32 +/- 1 degrees C, but mortality reached 100% when crayfish were transferred to 24 +/- 1 degrees C. Competitive PCR showed that viral levels at 32 +/- 1 degrees C remained at 10(5) copies mg(-1) tissue, while at 24 +/- 1 degrees C levels were significantly higher, rising from 10(4) to 10(10) copies mg(-1) tissue. These results suggest that hyperthermia reduces viral replication, but does not eliminate viral particles from WSSV-infected crayfish.


Asunto(s)
Astacoidea/virología , Calor , Replicación Viral/fisiología , Virus del Síndrome de la Mancha Blanca 1/fisiología , Animales , Cartilla de ADN/química , Branquias/virología , Reacción en Cadena de la Polimerasa/métodos , Análisis de Supervivencia , Factores de Tiempo
19.
J Zhejiang Univ Sci B ; 16(6): 487-95, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26055910

RESUMEN

While a high-fat diet (HFD) is assumed to be related to fat-mediated oxidative stress decreasing antioxidant enzyme activity, probiotics are believed to have positive effects on the regulation of HFD-induced obesity as well as lipid metabolism, energy homeostasis, and anti-oxidation. Because Bacillus subtilis B10 has beneficial effects on the abnormal lipid metabolism and the oxidative stress in HFD-induced obese mice, ICR mice were randomly assigned into an HFD group and the HFD was supplemented with 0.1% (w/w) Bacillus subtilis B10 (HFD+B10 group). Thereafter, 30-d treatments were run, and then hepatic lipid level and antioxidant status were measured. The expression of genes related to lipid metabolism and oxidative stress in the liver was determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). We found that HFD-induced obese mice treated with B10 showed a decrease in weight gain, serum glucose activity as well as hepatic triglyceride (TG), glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) activities. In addition, the gene expressions of antioxidant genes, glutathione reductase (GR), xanthine oxidase (XO), heat-shock protein 90 (Hsp90), and lipid synthesis gene 3ß-hydroxysteroid-∆24 reductase (DHCR24) in the HFD+B10 group were down-regulated, suggesting alleviation of oxidative stress, while the lipolysis gene 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), energy metabolism gene peroxisome proliferator-activated receptor α (PPARα) and the gene encoding tumor-suppressor protein p53 were up-regulated. The regulatory and positive effect of dietary supplementation of probiotic B10 suggests that it has a beneficial effect on the homeostasis of the lipid metabolism and on alleviating oxidative stress in HFD-induced obese mice.


Asunto(s)
Bacillus subtilis/fisiología , Metabolismo de los Lípidos , Obesidad/metabolismo , Obesidad/microbiología , Probióticos/administración & dosificación , Especies Reactivas de Oxígeno/metabolismo , Administración Oral , Animales , Grasas de la Dieta , Metabolismo Energético , Masculino , Ratones , Ratones Endogámicos ICR , Obesidad/dietoterapia , Especies Reactivas de Oxígeno/sangre , Resultado del Tratamiento
20.
World J Gastroenterol ; 10(6): 856-9, 2004 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-15040032

RESUMEN

AIM: To investigate effects of non-starch polysaccharides(NSP) enzymes on pancreatic and small intestinal digestive enzyme activities in piglet fed diets containing high amounts of barley. METHODS: Sixty crossbred piglets averaging 13.5 kg were randomly assigned to two treatment groups with three replications (pens) based on sex and mass. Each group was fed on the diet based on barley with or without added NSP enzymes (0.15%) for a 40-d period. At the end of the experiment the pigs were weighed. Three piglets of each group were chosen and slaughtered. Pancreas, digesta from the distal end of the duodenum and jejunal mucosa were collected for determination. Activities of the digestive enzymes trypsin, chymotrypsin, amylase and lipase were determined in the small intestinal sections as well as in homogenates of pancreatic tissue. Maltase, sucrase, lactase and gamma-glutamyl transpeptidase (gamma-GT) activities were analyzed in jejunal mucosa. RESULTS: Supplementation with NSP enzymes improved growth performance of piglets. It showed that NSP enzymes had no effect on digestive enzyme activities in pancreas, but decreased the activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents by 57.56%, 76.08%, 69.03% and 40.22%(P<0.05) compared with control, and increased gamma-GT activities in jejunal mucosa by 118.75%(P<0.05). CONCLUSION: Supplementation with NSP enzymes in barley based diets could improve piglets' growth performance, decrease activities of proteolytic enzyme, trypsin, amylase and lipase in duodenal contents and increase gamma-GT activities in jejunal mucosa.


Asunto(s)
Animales Recién Nacidos/metabolismo , Dieta , Enzimas/farmacología , Hordeum , Intestino Delgado/metabolismo , Páncreas/metabolismo , Polisacáridos/metabolismo , Animales , Digestión/fisiología , Enzimas/metabolismo , Porcinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA