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1.
BMC Immunol ; 25(1): 29, 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38730320

RESUMEN

BACKGROUND: Several PD-1 antibodies approved as anti-cancer therapies work by blocking the interaction of PD-1 with its ligand PD-L1, thus restoring anti-cancer T cell activities. These PD-1 antibodies lack inter-species cross-reactivity, necessitating surrogate antibodies for preclinical studies, which may limit the predictability and translatability of the studies. RESULTS: To overcome this limitation, we have developed an inter-species cross-reactive PD-1 antibody, GNUV201, by utilizing an enhanced diversity mouse platform (SHINE MOUSE™). GNUV201 equally binds to human PD-1 and mouse PD-1, equally inhibits the binding of human PD-1/PD-L1 and mouse PD-1/PD-L1, and effectively suppresses tumor growth in syngeneic mouse models. The epitope of GNUV201 mapped to the "FG loop" of hPD-1, distinct from those of Keytruda® ("C'D loop") and Opdivo® (N-term). Notably, the structural feature where the protruding epitope loop fits into GNUV201's binding pocket supports the enhanced binding affinity due to slower dissociation (8.7 times slower than Keytruda®). Furthermore, GNUV201 shows a stronger binding affinity at pH 6.0 (5.6 times strong than at pH 7.4), which mimics the hypoxic and acidic tumor microenvironment (TME). This phenomenon is not observed with marketed antibodies (Keytruda®, Opdivo®), implying that GNUV201 achieves more selective binding to and better occupancy on PD-1 in the TME. CONCLUSIONS: In summary, GNUV201 exhibited enhanced affinity for PD-1 with slow dissociation and preferential binding in TME-mimicking low pH. Human/monkey/mouse inter-species cross-reactivity of GNUV201 could enable more predictable and translatable efficacy and toxicity preclinical studies. These results suggest that GNUV201 could be an ideal antibody candidate for anti-cancer drug development.


Asunto(s)
Reacciones Cruzadas , Inmunoterapia , Receptor de Muerte Celular Programada 1 , Animales , Humanos , Receptor de Muerte Celular Programada 1/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Ratones , Reacciones Cruzadas/inmunología , Inmunoterapia/métodos , Concentración de Iones de Hidrógeno , Neoplasias/inmunología , Neoplasias/terapia , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Antígeno B7-H1/antagonistas & inhibidores , Línea Celular Tumoral , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Inhibidores de Puntos de Control Inmunológico/farmacología , Epítopos/inmunología , Anticuerpos Monoclonales Humanizados/inmunología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/farmacología , Ratones Endogámicos C57BL , Femenino
2.
Food Microbiol ; 107: 104094, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35953183

RESUMEN

The closely related species, Lacticaseibacillus casei, L. paracasei, L. rhamnosus, L. chiayiensis, and L. zeae, are difficult to accurately discriminate by conventional identification methods. In this study, the bioTyper and in-house database of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was evaluated to discriminate five Lacticaseibacillus species. From the mass spectra of 130 isolates aligned with databases, 118 strains were correctly identified. On the other hand, databases could not accurately differentiate 12 isolates such as L. casei, L. rhamnosus and L. chiayiensis because the same colony was identified as two species with similar score. To overcome the database's limitations, the mass spectra were analyzed to discover species-specific protein peaks. The peaks at 6731 ± 1, 6849 ± 1, 7008 ± 1, 7376 ± 1, and 2593 ± 1 m/z were specifically found in the reference strains of L. casei, L. paracasei, L. rhamnosus, L. chiayiensis, and L. zeae, respectively. These peaks confirmed that the five peaks were consistently present in each species using 130 strains isolated from food samples. Our results demonstrate the high-resolution of MALDI-TOF MS technique for rapid and accurate classification of five species when used with databases coupled to specific peaks.


Asunto(s)
Lacticaseibacillus casei , Rayos Láser , Especificidad de la Especie , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
3.
Food Microbiol ; 94: 103641, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33279067

RESUMEN

Complex interactions occur within microbial communities during the fermentation process of kimchi. Identification of these microorganisms provides the essential information required to improve food quality and to understand their role in this process. This was the first study to compare two methods for accuracy in the identification of microbial community changes during the fermentation of kimchi by comparing a culture-dependent (MALDI-TOF MS analysis) and a culture-independent method (high-throughput sequencing) of 16S rRNA gene fragment). Members of the Lactobacillus-related genera, Leuconostoc, and Weissella were identified as the predominant microorganisms by both methods. The culture-independent method was able to additionally identify non-lactic acid bacteria and yeasts, such as Kazachstania in kimchi. However, high-throughput sequencing failed to accurately recognize Latilactobacillus sakei, Latilactobacillus curvatus, Lactiplantibacillus plantarum, and W. cibaria, which played an important role in kimchi fermentation, as this method only allowed for identification at the genus level. Conversely, MALDI-TOF MS analysis could identify the isolates at the species level. Also, culture-dependent method could identify predominant species in viable cell communities. The culture-dependent method and culture-independent method provided complementary information by producing a more comprehensive view of the microbial ecology in fermented kimchi.


Asunto(s)
Bacterias/aislamiento & purificación , Brassica/microbiología , Alimentos Fermentados/microbiología , Microbiota , Levaduras/aislamiento & purificación , Bacterias/química , Bacterias/clasificación , Bacterias/genética , Fermentación , Secuenciación de Nucleótidos de Alto Rendimiento , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Verduras/microbiología , Levaduras/clasificación , Levaduras/genética , Levaduras/metabolismo
4.
Environ Geochem Health ; 43(9): 3303-3321, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33034807

RESUMEN

Biochar derived from food waste was modified with Fe to enhance its adsorption capacity for As(III), which is the most toxic form of As. The synthesis of Fe-impregnated food waste biochar (Fe-FWB) was optimized using response surface methodology (RSM), and the pyrolysis time (1.0, 2.5, and 4.0 h), temperature (300, 450, and 600 °C), and Fe concentration (0.1, 0.3, and 0.5 M) were set as independent variables. The pyrolysis temperature and Fe concentration significantly influenced the As(III) removal, but the effect of pyrolysis time was insignificant. The optimum conditions for the synthesis of Fe-FWB were 1 h and 300 °C with a 0.42-M Fe concentration. Both physical and chemical properties of the optimized Fe-FWB were studied. They were also used for kinetic, equilibrium, thermodynamic, pH, and competing anion studies. Kinetic adsorption experiments demonstrated that the pseudo-second-order model had a superior fit for As(III) adsorption than the pseudo-first-order model. The maximum adsorption capacity derived from the Langmuir model was 119.5 mg/g, which surpassed that of other adsorbents published in the literature. Maximum As(III) adsorption occurred at an elevated pH in the range from 3 to 11 owing to the presence of As(III) as H2AsO3- above a pH of 9.2. A slight reduction in As(III) adsorption was observed in the existence of bicarbonate, hydrogen phosphate, nitrate, and sulfate even at a high concentration of 10 mM. This study demonstrates that aqueous solutions can be treated using Fe-FWB, which is an affordable and readily available resource for As(III) removal.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Alimentos , Concentración de Iones de Hidrógeno , Cinética , Contaminantes Químicos del Agua/análisis
5.
Biosci Biotechnol Biochem ; 84(5): 1001-1012, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31960754

RESUMEN

Crude extracts and phytochemical compounds derived from Annona muricata leaves have been demonstrated to exert neuroprotective effects. However, the neuroprotective effects of Annona muricata leaves-derived polysaccharide extracts (ALPs) have not been investigated. ALP treatment was shown to induce concentration-dependent antioxidant activity in HT22 cells, and to increase cell viability in H2O2-treated HT22 cells. These effects were correlated with a decrease in major components of oxidation, including: Ca2+, ROS, and malondialdehyde (MDA). Mediators of the intracellular response to oxidation, including Bax, cytochrome c, and cleaved caspases-3, -8, -9, MAPKs, and NF-κB, were positively influenced by ALP treatment under conditions of H2O2-mediated oxidative stress. In addition, ALP restored the expression of superoxide dismutase (SOD) and associated signaling pathways (PARP, PI3K/AKT and Nrf2-mediated HO-1/NQO-1) following H2O2 treatment. These results provide new pharmacological evidence that ALP facilitates neuroprotection via prevention of neuronal oxidative stress and promotion of cell survival signaling pathways.Abbreviations: ABTS: 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonicacid); AD: Alzheimer's disease; ALP: polysaccharide extracts isolated from Annona muricata leaves; ARE: antioxidant response element; DPPH: 1,1-diphenyl-picrylhydrazyl; DCFH-DA: 2',7'-dichlorofluorescin diacetate; ECL: electrochemiluminescence; ERK: extracellular regulated kinase; FBS: Fetal bovine serum; FITC: fluorescein isothiocyanate; FRAP: ferric reducing antioxidant power; HO-1: Heme oxygenase-1; JNK: c-jun N-terminal kinase; MAPKs: mitogen-activated protein kinases; MDA: malondialdehyde; MMP: mitochondrial membrane potential; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide; NQO1: NAD(P)H:quinine oxidoreductase 1, Nrf2: nuclear factor-E2-related factor 2; PD: parkinson's disease; PI3K: phosphatidylinositol-3kinase; PVDF: polyvinylidene difluoride; ROS: reactive oxygen species; SOD: Superoxidedismutase; TPTZ: tripydyltriazine.


Asunto(s)
Annona/química , Antioxidantes/farmacología , Peróxido de Hidrógeno/farmacología , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Extractos Vegetales/farmacología , Polisacáridos/farmacología , Animales , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Malondialdehído/análisis , Malondialdehído/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Superóxido Dismutasa/análisis , Superóxido Dismutasa/metabolismo
6.
Food Microbiol ; 90: 103485, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32336352

RESUMEN

The Lactobacillus casei group, which includes the closely related species L. casei, L. paracasei, L. rhamnosus, and L. chiayiensis, has been under debate regarding its taxonomy because of the difficulty in distinguishing the species from each other. In the present study, we developed a novel real-time PCR assay for distinguishing the L. casei group species. The pan-genome, as determined by the genomes of 44 strains, comprised 6789 genes, comparative genomic analysis showed that L. casei group strains were classified by species. Based on these results, species-specific genes were identified, and primers were designed from those genes. Real-time PCR clearly distinguished each species of the L. casei group and specifically amplified only to the target species. The method was applied to 29 probiotic products, and the detected results and label claims were compared. Total 23 products were in accordance with the label claims, and the remaining products contained species different from those stated in the label claims. Our method can rapidly and accurately distinguish the L. casei group species in a single reaction. Hence, our assay can be applied to identify L. casei group species from food or environmental samples and to accurately determine the nomenclature of the species.


Asunto(s)
ADN Bacteriano/genética , Genómica/métodos , Lacticaseibacillus casei/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Cartilla de ADN/genética , Lacticaseibacillus casei/clasificación , Probióticos , Análisis de Secuencia de ADN
7.
Biosci Biotechnol Biochem ; 82(8): 1344-1358, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29629628

RESUMEN

This study was carried out to evaluate the neuroprotective activity of polysaccharide extracts isolated from Perilla frutescens (PEPF) in H2O2-treated HT22 hippocampus cells. The PEPF treatment was found to increase the anti-oxidant activities of HT22 hippocampus cells. PEPF treatment resulted in a significant protection of HT22 hippocampus cells against H2O2-induced neurotoxicity, this protection ultimately occurred through an inhibition of ROS-mediated intracellular Ca2+ levels leading to MAPKs and NF-κB, as well as the accumulation of PI3K/AKT and Nrf2-mediated HO-1/NQO1 pathways. Furthermore, PEPF not only decreased the expression of Bax, cytochrome c, and cleaved caspases-3, -8, and -9, but also increased the expression of PARP and Bcl-2 in the H2O2-treated HT22 hippocampus cells, which overall contributed to the neuroprotective action. PEPF retains its mitochondrial membrane potential and reduces the elevated levels of sub-G1 phase and apoptotic morphological features induced by H2O2. It also reduces the malondialdehyde levels and enhances the intracellular SOD activity.


Asunto(s)
Hipocampo/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Perilla frutescens/química , Polisacáridos/farmacología , Animales , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Caspasas/metabolismo , Línea Celular , Citocromos c/metabolismo , Fase G1/efectos de los fármacos , Hipocampo/citología , Hipocampo/metabolismo , Malondialdehído/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , FN-kappa B/metabolismo , Fármacos Neuroprotectores/aislamiento & purificación , Polisacáridos/aislamiento & purificación , Proteínas Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Especies Reactivas de Oxígeno/metabolismo , Proteína X Asociada a bcl-2/metabolismo
8.
Environ Pollut ; 334: 122166, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37429491

RESUMEN

Fenton sludge is a byproduct of the Fenton process that contains large amounts of Fe and Ca. Because of the secondary contamination generated during the disposal of this byproduct, ecofriendly treatment methods are needed. In this study, we used Fenton sludge to remove the Cd discharged from a zinc smelter factory, using thermal activation to enhance the Cd adsorption capacity. Among the various temperatures considered (300-900 °C), the Fenton sludge that was thermally activated at 900 °C (TA-FS-900) adsorbed the highest amount of Cd because of its high specific surface area and high Fe content. Cd was adsorbed onto TA-FS-900 via complexation with C-OH, C-COOH, FeO-, and FeOH and cation exchange with Ca2+. The maximum adsorption of TA-FS-900 was 260.2 mg/g, indicating that TA-FS-900 is an efficient adsorbent, comparable to those reported in the literature. The initial Cd concentration in the zinc smelter wastewater discharged was 105.7 mg/L, 98.4% of which was removed by applying TA-FS-900, suggesting the applicability of TA-FS-900 for real wastewater containing high concentrations of various cations and anions. The leaching of heavy metals from TA-FS-900 was within the EPA standard limits. We concluded that the environmental impact of Fenton sludge disposal can be reduced, and the use of Fenton sludge can add value to the treatment of industrial wastewater in terms of the circular economy and environment.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Aguas del Alcantarillado , Zinc , Cadmio , Estudios de Factibilidad , Eliminación de Residuos Líquidos/métodos , Adsorción
9.
Curr Genet ; 58(3): 179-89, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22531843

RESUMEN

Protein-protein interactions play important roles in controlling many cellular events. To date, several techniques have been developed for detection of protein-protein interactions in living cells, among which split luciferase complementation has been applied in animal and plant cells. Here, we examined whether the split luciferase assay could be used in filamentous ascomycetes, such as Gibberella zeae and Cochliobolus heterostrophus. The coding sequences of two strongly interacting proteins (the F-box protein, FBP1, and its partner SKP1) in G. zeae, under the control of the cryparin promoter from Cryphonectria parasitica, were translationally fused to the C- and N-terminal fragments of firefly luciferase (luc), respectively. Each fusion product inserted into a fungal transforming vector carrying the gene for resistance to either geneticin or hygromycin B, was transformed into both fungi. We detected complementation of split luciferase proteins driven by interaction of the two fungal proteins with a high luminescence intensity-to-background ratio only in the fungal transformants expressing both N-luc and C-luc fusion constructs. Using this system, we also confirmed a novel protein interaction between transcription factors, GzMCM1 and FST12 in G. zeae, which could hardly be proven by the yeast two-hybrid method. This is the first study demonstrating that monitoring of split luciferase complementation is a sensitive and efficient method of studying in vivo protein-protein interactions in filamentous ascomycetes.


Asunto(s)
Ascomicetos/metabolismo , Proteínas Fúngicas/metabolismo , Luciferasas de Luciérnaga/genética , Mapeo de Interacción de Proteínas/métodos , Ascomicetos/genética , Fructosa-Bifosfatasa/genética , Fructosa-Bifosfatasa/metabolismo , Proteínas Fúngicas/genética , Orden Génico , Prueba de Complementación Genética , Luciferasas de Luciérnaga/metabolismo , Plásmidos , Unión Proteica , Proteínas Quinasas Asociadas a Fase-S/genética , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Transformación Genética
10.
J Affect Disord ; 318: 185-190, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36057289

RESUMEN

BACKGROUND: The moderating effect of cognitive function on the association between social support and late-life depressive symptoms has not been thoroughly investigated. Identifying cognitive function as a possible moderator of this association might help plan community-based interventions for late-life depressive symptoms. METHODS: Participants were community-dwelling older adults who visited a community-based mental health center. The ENRICHD Social Support Instrument and the Montgomery-Asberg Depression Rating Scale were used to evaluate social support and depressive symptoms, respectively. Cognitive function was assessed using the Korean version of the Mini-Mental State Examination. Data from 1088 and 506 participants were included in the cross-sectional and longitudinal analyses, respectively. Multiple linear regression analysis was performed to assess the effects of social support on depressive symptoms and the possible moderating effect of cognition. RESULTS: After adjusting for possible confounders, greater social support at baseline was associated with fewer depressive symptoms in both cross-sectional (estimate = -0.25 standard error [SE] = 0.03, P < 0.001) and longitudinal analyses (estimate = -0.11, SE = 0.05, P = 0.014). Moreover, the association between social support and depressive symptoms was significantly moderated by cognitive function (P for interaction < 0.001 for cross-sectional analysis, and P for interaction = 0.011 for longitudinal analysis). LIMITATIONS: The tool for assessing social support was self-reported. There may have been a selection bias in the study sample. CONCLUSIONS: Greater social support was associated with fewer late-life depressive symptoms in both analyses. However, social support may have less benefits for alleviating depressive symptoms in older adults with cognitive decline.


Asunto(s)
Depresión , Vida Independiente , Anciano , Cognición , Estudios Transversales , Depresión/psicología , Humanos , Apoyo Social
11.
J Microbiol Biotechnol ; 31(2): 280-289, 2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33144553

RESUMEN

Genetic markers currently used for the discrimination of Lactobacillus delbrueckii subspecies have low efficiency for identification at subspecies level. Therefore, our objective in this study was to select novel genetic markers for accurate identification and discrimination of six L. delbrueckii subspecies based on pangenome analysis. We evaluated L. delbrueckii genomes to avoid making incorrect conclusions in the process of selecting genetic markers due to mislabeled genomes. Genome analysis showed that two genomes of L. delbrueckii subspecies deposited at NCBI were misidentified. Based on these results, subspecies-specific genetic markers were selected by comparing the core and pangenomes. Genetic markers were confirmed to be specific for 59,196,562 genome sequences via in silico analysis. They were found in all strains of the same subspecies, but not in other subspecies or bacterial strains. These genetic markers also could be used to accurately identify genomes at the subspecies level for genomes known at the species level. A real-time PCR method for detecting three main subspecies (L. delbrueckii subsp. delbrueckii, lactis, and bulgaricus) was developed to cost-effectively identify them using genetic markers. Results showed 100% specificity for each subspecies. These genetic markers could differentiate each subspecies from 44 other lactic acid bacteria. This real-time PCR method was then applied to monitor 26 probiotics and dairy products. It was also used to identify 64 unknown strains isolated from raw milk samples and dairy products. Results confirmed that unknown isolates and subspecies contained in the product could be accurately identified using this real-time PCR method.


Asunto(s)
Lactobacillus delbrueckii/clasificación , Lactobacillus delbrueckii/genética , Técnicas de Tipificación Bacteriana , Marcadores Genéticos , Genoma Bacteriano , Lactobacillus delbrueckii/aislamiento & purificación , Lactobacillus delbrueckii/metabolismo , Reacción en Cadena de la Polimerasa , Especificidad de la Especie
12.
Obstet Gynecol Sci ; 59(2): 163-7, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27004210

RESUMEN

The transobturator tape (TOT) method is the recent minimally invasive midurethral sling surgery. The TOT method was invented to reduce complication rate of surgical technique for female stress urinary incontinence. Pelvic bleeding following TOT procedure, although extremely rare, could be occurred. We presented three cases which treat pelvic arterial bleeding after midurethral sling (TOT and tension-free vaginal tape Secur) surgery via pelvic artery embolization. Therefore we report our cases with brief review of the literature.

13.
J Menopausal Med ; 20(1): 7-13, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25371886

RESUMEN

OBJECTIVES: To investigate awareness and experience of menopausal symptom and hormone therapy in Korean postmenopausal women. METHODS: A total of 570 postmenopausal women were accepted our survey. The women filled out the questionnaires composed of medical and surgical history, menopausal age and symptom, demand of treatment on menopausal symptom, and personal method for overcoming the symptom. Also, we make inquiries about experience of hormone therapy, concern about hormone therapy, improvement of menopausal symptom after therapy, adverse effect, and cause of cease the therapy. RESULTS: According to the survey, 80% (456/570) of the women experienced menopausal symptom. When they felt the symptom at first, 47% (213/570) of women was 46-50 years old. The most common menopausal symptom was hot flushes (141/570). A number of Korean women regarded that menopause was a natural process of ageing (69%). Eighty two % of women thought to need to have treatment on menopausal symptom. However, only half (43%) visited doctor. The most concerned disease after menopause they had answered was osteoporosis (60%) but only 22% of women were taken regular check-up of bone mineral density. The common causes were unwilling to do treatment were concern about adverse effect (51%) and indefinite fear of cancer (32%). Moreover, many women got diverse information about menopause from the mass media than professional advice. CONCLUSION: Only a minority of Korean postmenopausal women with menopausal symptoms had taken a hormone therapy. We should provide appropriate education and counsel to Korean peri-menopause women.

14.
J Microbiol Biotechnol ; 23(3): 430-5, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23462018

RESUMEN

Multidrug resistance, especially multidrug efflux mechanisms that extrude structurally unrelated cytotoxic compounds from the cell by multidrug transporters, is a serious problem and one of the main reasons for the failure of therapeutic treatment of infections by pathogenic microorganisms as well as of cancer cells. Streptococcus mutans is considered one of the primary causative agents of dental caries and periodontal disease, which comprise the most common oral diseases. A fragment of chromosomal DNA from S. mutans KCTC3065 was cloned using Escherichia coli KAM32 as host cells lacking major multidrug efflux pumps. Although E. coli KAM32 cells were very sensitive to many antimicrobial agents, the transformed cells harboring a recombinant plasmid became resistant to several structurally unrelated antimicrobial agents such as tetracycline, kanamycin, rhodamin 6G, ampicillin, acriflavine, ethidium bromide, and tetraphenylphosphonium chloride. This suggested that the cloned DNA fragment carries a gene encoding a multidrug efflux pump. Among 49 of the multidrug-resistant transformants, we report the functional gene cloning and characterization of the function of one multidrug efflux pump, namely MdeA from S. mutans, which was expressed in E. coli KAM32. Judging from the structural and biochemical properties, we concluded that MdeA is the first cloned and characterized multidrug efflux pump using the proton motive force as the energy for efflux drugs.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Streptococcus mutans/efectos de los fármacos , Antibacterianos/metabolismo , Antibacterianos/farmacología , Transporte Biológico Activo , Clonación Molecular , Escherichia coli/genética , Sustancias Intercalantes/metabolismo , Sustancias Intercalantes/farmacología , Compuestos Onio/metabolismo , Compuestos Onio/farmacología , Compuestos Organofosforados/metabolismo , Compuestos Organofosforados/farmacología , Fuerza Protón-Motriz , Streptococcus mutans/genética , Streptococcus mutans/metabolismo
15.
FEMS Microbiol Lett ; 337(2): 89-96, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22998651

RESUMEN

Members of the Fusarium graminearum species (Fg) complex, which are homothallic ascomycetous species, carry two opposite mating-type (MAT) loci in a single nucleus for controlling sexual development. We investigated the roles of three (MAT1-1-1, MAT1-1-2, and MAT1-1-3) and two (MAT1-2-1 and MAT1-2-3) transcripts located at both loci in representative Fg complex species (F. graminearum and Fusarium asiaticum). In self-fertile F. graminearum strains, the transcript levels of MAT1-1-1, MAT1-2-1, and MAT1-2-3 peaked 2 days after sexual induction (dai) and then remained high until 12 dai, whereas MAT1-1-2 and MAT1-1-3 transcripts reached peak levels between 4 and 8 dai. In contrast, all of the MAT transcripts in self-sterile F. asiaticum strains accumulated at much lower levels than those in F. graminearum during the entire time. Targeted gene deletions confirmed that MAT1-1-1, MAT1-1-2, MAT1-1-3, and MAT1-2-1 were essential for self-fertility in F. graminearum, but MAT1-2-3 was not. All MAT-deleted strains (except ΔMAT1-2-3) produced recombinant perithecia when outcrossed to a self-fertile strain. These results indicate that developmental up-regulation of the individual MAT genes in both a proper fashion and quantity is critical for sexual development, and that alterations in the gene expression could be attributed to the variation in self-sterility among the Fg complex.


Asunto(s)
Fusarium/crecimiento & desarrollo , Fusarium/genética , Genes del Tipo Sexual de los Hongos , Transcripción Genética , Eliminación de Gen , Perfilación de la Expresión Génica , Genes Fúngicos , Factores de Tiempo
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