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1.
J Environ Manage ; 363: 121434, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38861886

RESUMEN

Despite benefits such as lower water and working volume requirements, thermophilic high solids anaerobic digestion (THSAD) often fails due to the rapid build-up of volatile fatty acids (VFAs) and the associated drop in pH. Use of conductive materials (CM) can promote THSAD through stimulation of direct interspecies electron transfer (DIET), while the need for their constant dosing due to poor separation from effluent impairs economic feasibility. This study used an approach of spatially separating magnetite and granular activated carbon (GAC) from the organic fraction of municipal solid waste (OFMSW) in a single reactor for THSAD. GAC and magnetite addition could both mitigate the severe inhibition of methanogenesis after VFAs build-up to ∼28-30 g/L, while negligible methane production was observed in the control group. The highest methane yield (286 mL CH4/g volatile solids (VS)) was achieved in magnetite-added reactors, while the highest maximum CH4 production rates (26.38 mL CH4/g VS/d) and lowest lag-phase (2.83 days) were obtained in GAC-added reactors. The enrichment of GAC and magnetite biofilms with various syntrophic and potentially electroactive microbial groups (Ruminiclostridium 1, Clostridia MBA03, Defluviitoga, Lentimicrobiaceae) in different relative abundances indicates the existence of specific preferences of these groups for the nature of CM. According to predicted basic metabolic functions, CM can enhance cellular processes and signals, lipid transport and metabolism, and methane metabolism, resulting in improved methane production. Rearrangement of metabolic pathways, formation of pili-like structures, enrichment of biofilms with electroactive groups and a significant improvement in THSAD performance was attributed to the enhancement of the DIET pathway. Promising results obtained in this work due to the spatial separation of the bulk OFMSW and CM can be useful for modeling larger-scale THSAD systems with better recovery of CM and cost-effectiveness.


Asunto(s)
Reactores Biológicos , Metano , Residuos Sólidos , Anaerobiosis , Metano/metabolismo , Ácidos Grasos Volátiles/metabolismo , Eliminación de Residuos/métodos , Óxido Ferrosoférrico/química
2.
J Environ Manage ; 341: 118124, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37172349

RESUMEN

Currently, the phenomenon of direct interspecies electron transfer (DIET) is of great interest in the technology of anaerobic digestion (AD) due to potential performance benefits. However, the conditions for the occurrence of DIET and its limits on improving AD under conditions close to real have not been studied enough. This research is concentrated on the effect of conductive carbon cloth (R3), in comparison with a dielectric fiberglass cloth (R2) and control (R1), on the AD performance in large (90 L) thermophilic reactors, fed with a mixture of simulated organic fraction of municipal solid waste and sewage sludge. While organic loading rate (OLR) was gradually increased from 2.4 to 8.66 kg VS/(m3 day), a statistically significant (p < 0.05) difference in biogas production was observed between R1 and both R2 and R3. However, at a maximum OLR of 12.12 kg VS/(m3 day) in R3, an increase in biogas production (p < 0.05) was observed both compared to R1 (by 8.97%) and R2 (by 4.24%). The content of volatile fatty acids in R3 as a whole was the lowest, especially at the maximum OLR. Biofilm on carbon cloth was rich in syntrophic microorganisms of the genera Tepidanaerobacter, as well as Defluviitoga, capable of DIET in mixed cultures with Methanothrix, which was the most abundant methanogen in biofilm. Suspended Bifidobacterium, Fervidobacterium and Anaerobaculum were negatively affected, while Defluviitoga, Methanothermobacter and Methanosarcina, on the contrary, were positively affected by the increase in OLR and showed, respectively, a negative and positive correlation (p < 0.05) with the main AD performance parameters.


Asunto(s)
Carbono , Microbiota , Anaerobiosis , Biocombustibles , Bacterias , Aguas del Alcantarillado , Reactores Biológicos/microbiología , Metano
3.
Clin Exp Rheumatol ; 39(5): 982-987, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33427619

RESUMEN

OBJECTIVES: NKG2D ligands (NKG2DLs) are stress-inducible molecules involved in multiple inflammatory settings. In this work, we quantified MICA, an NKG2DL, in the synovial fluid of patients suffering various arthritides and measured Nkg2dLs gene expression in murine models of acute joint inflammation. METHODS: Soluble MICA (sMICA) was quantified by ELISA is synovial fluids harvested from patients suffering osteoarthritis, rheumatoid arthritis, psoriatic arthritis, calcium pyrophosphate crystal arthritis, urate crystal arthritis and reactive arthritis. Transcripts encoding murine NKG2DLs were quantified by RT-qPCR in the joints of mouse models of rheumatoid arthritis, urate crystal arthritis and osteoarthritis. RESULTS: Marked overproduction of sMICA was observed in the synovial fluid of RA patients. Mouse studies highlighted the complex transcriptional regulation of Nkg2d ligands encoding genes depending on the inflammatory setting and microenvironment CONCLUSIONS: sMICA quantification could be an interesting biomarker to identify acute inflammation in RA patients in whom classical markers (i.e. anti-citrullinated protein antibodies, ACPA) are undetectable.


Asunto(s)
Artritis Reumatoide , Subfamilia K de Receptores Similares a Lectina de Células NK , Animales , Anticuerpos Antiproteína Citrulinada , Artritis Reumatoide/genética , Humanos , Ligandos , Ratones , Subfamilia K de Receptores Similares a Lectina de Células NK/genética , Líquido Sinovial
4.
Hum Mol Genet ; 26(13): 2565-2576, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28379387

RESUMEN

The association of primary Sjögren's syndrome (pSS) with Major Histocompatibility Complex (MHC) alleles is quintessential of MHC-disease associations. Indeed, although disease associations with classical HLA class I and II alleles/haplotypes are amply documented, further dissection is often prevented by the strong linkage disequilibrium across the entire MHC complex. Here we study the association of pSS, not with HLA genes, but with the non-conventional MHC encoded class I gene, MICA (MHC class I chain-related gene A). MICA is selectively expressed within epithelia, and is the major ligand for the activatory receptor, NKG2D, both attributes relevant to pSS' etiology. MICA-pSS association was studied in two independent (French and UK) cohorts representing a total of 959 cases and 1,043 controls. MICA*008 allele was shown to be significantly associated with pSS (pcor=2.61 × 10-35). A multivariate logistic regression showed that this association was independent of all major known MHC-linked risk loci/alleles, as well as other relevant candidate loci that are in linkage disequilibrium with MICA*008 i.e. HLA-B*08:01, rs3131619 (T), MICB*008, TNF308A, HLA-DRB1*03:01 and HLA-DRB1*15:01 (P = 1.84 × 10-04). Furthermore, independently of the MICA*008 allele, higher levels of soluble MICA proteins were detected in sera of pSS patients compared to healthy controls. This study hence defines MICA as a new, MHC-linked, yet HLA-independent, pSS risk locus and opens a new front in our understanding of the still enigmatic pathophysiology of this disease. The fact that the soluble MICA protein is further amplified in MICA*008 carrying individuals, might also be relevant in other auto-immune diseases and cancer.


Asunto(s)
Antígenos de Histocompatibilidad Clase I/genética , Síndrome de Sjögren/genética , Adulto , Alelos , Femenino , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad , Antígenos HLA-B/genética , Cadenas HLA-DRB1/genética , Haplotipos , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Desequilibrio de Ligamiento , Complejo Mayor de Histocompatibilidad/genética , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Población Blanca/genética
5.
Blood ; 128(15): 1979-1986, 2016 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-27549307

RESUMEN

Graft-versus-host disease (GVHD) is among the most challenging complications in unrelated donor hematopoietic cell transplantation (HCT). The highly polymorphic MHC class I chain-related gene A, MICA, encodes a stress-induced glycoprotein expressed primarily on epithelia. MICA interacts with the invariant activating receptor NKG2D, expressed by cytotoxic lymphocytes, and is located in the MHC, next to HLA-B Hence, MICA has the requisite attributes of a bona fide transplantation antigen. Using high-resolution sequence-based genotyping of MICA, we retrospectively analyzed the clinical effect of MICA mismatches in a multicenter cohort of 922 unrelated donor HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 10/10 allele-matched HCT pairs. Among the 922 pairs, 113 (12.3%) were mismatched in MICA MICA mismatches were significantly associated with an increased incidence of grade III-IV acute GVHD (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.50-2.23; P < .001), chronic GVHD (HR, 1.50; 95% CI, 1.45-1.55; P < .001), and nonelapse mortality (HR, 1.35; 95% CI, 1.24-1.46; P < .001). The increased risk for GVHD was mirrored by a lower risk for relapse (HR, 0.50; 95% CI, 0.43-0.59; P < .001), indicating a possible graft-versus-leukemia effect. In conclusion, when possible, selecting a MICA-matched donor significantly influences key clinical outcomes of HCT in which a marked reduction of GVHD is paramount. The tight linkage disequilibrium between MICA and HLA-B renders identifying a MICA-matched donor readily feasible in clinical practice.


Asunto(s)
Enfermedad Injerto contra Huésped , Antígenos HLA/genética , Trasplante de Células Madre Hematopoyéticas , Antígenos de Histocompatibilidad Clase I/genética , Prueba de Histocompatibilidad , Desequilibrio de Ligamiento , Enfermedad Aguda , Adolescente , Adulto , Anciano , Aloinjertos , Niño , Preescolar , Enfermedad Crónica , Femenino , Enfermedad Injerto contra Huésped/epidemiología , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/genética , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Subfamilia K de Receptores Similares a Lectina de Células NK/genética , Estudios Retrospectivos
6.
Adv Exp Med Biol ; 897: 103-11, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26566644

RESUMEN

103 strains of lactic acid bacteria of Lactobacillus genus were isolated from natural sources and identified for genus and species level with API tests and 16S rRNA sequencing. However, only 27 strains from isolated cultures demonstrated a high stability to gastric stress and from that - only 15 strains were highly resistant to intestinal stress. Results indicated that only some isolated cultures of lactobacilli possessed potential probiotical properties and could serve as new probiotics for dairy industry with high resistance to gastro-intestinal stresses.


Asunto(s)
Lactobacillus , Probióticos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Estrés Fisiológico , Animales , Industria Lechera , Microbiología de Alimentos , Humanos , Lactobacillus/clasificación , Lactobacillus/genética , Lactobacillus/crecimiento & desarrollo , Lactobacillus/aislamiento & purificación , Probióticos/clasificación , Probióticos/aislamiento & purificación
7.
Biochim Biophys Acta Gen Subj ; 1867(5): 130345, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36889447

RESUMEN

Calpain and calpastatin are the key components of the calcium-dependent proteolytic system. Calpains are regulatory, calcium-dependent, cytoplasmic proteinases, and calpastatin is the endogenous inhibitor of calpains. Due to the correlation between changes in the activity of the calpain-calpastatin system in the brain and central nervous system (CNS) pathology states, this proteolytic system is a prime focus of research on CNS pathological processes, generally characterized by calpain activity upregulation. The present review aims to generalize existing data on cerebral calpain distribution and function through mammalian ontogenesis. Special attention is given to the most recent studies on the topic as more information on calpain-calpastatin system involvement in normal CNS development and functioning has become available. We also discuss data on calpain and calpastatin activity and production in different brain regions during ontogenesis as comparative analysis of these results in association with ontogeny processes can reveal brain regions and developmental stages with pronounced function of the calpain system.


Asunto(s)
Calcio , Calpaína , Animales , Calpaína/metabolismo , Calcio/metabolismo , Proteínas de Unión al Calcio/metabolismo , Encéfalo/metabolismo , Péptido Hidrolasas , Mamíferos/metabolismo
8.
Sci Total Environ ; 839: 156073, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-35618137

RESUMEN

The activation of direct interspecies electron transfer (DIET) by the supplementation of conductive materials is one of the effective and available methods to enhance anaerobic digestion (AD). Microorganisms that colonize the surface of these materials form biofilms, the study of which could provide new insights into the character of the DIET process and its effect on AD. The present study focused on AD performance, microbial community, as well as morphological and topological features of biofilms on various materials used to promote DIET during AD of low-concentration swine manure. The best AD characteristics were observed in stainless steel mesh (SM)/digested cow manure (CM) and polyester felt (PF)/digested sewage sludge (SS) combinations used as material/inoculum, respectively. Thus, potential methane yields in CM-SM and SS-PF were up to 26.4% and 26.2% higher compared to the corresponding controls. Microbial analysis of biofilms revealed the dominance of putatively syntrophic bacteria of the MBA03 group of the Limnochordia class in CM inoculated reactors, and syntrophic proteolytic bacteria of the genus Coprothermobacter and acetogenic Clostridium sensu stricto 1, known for their ability to carry out DIET, in SS inoculated reactors. Biofilms on non-conductive materials contained pili-like structures, which were observed only in SS inoculated reactors. Polyester felt tended to biofoul better than carbon felt, resulting in up to 2.8, 3.2 and 1.8 higher nucleic acid, extracellular polymeric substances, and total biomass content, respectively, depending on the inoculum. These results provide new insights into the different types of DIET that can occur in low-loaded AD systems with attached growth.


Asunto(s)
Reactores Biológicos , Estiércol , Anaerobiosis , Animales , Electrones , Metano , Poliésteres , Aguas del Alcantarillado/microbiología , Acero Inoxidable , Porcinos
9.
Nat Med ; 28(5): 989-998, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35288692

RESUMEN

The identity of histocompatibility loci, besides human leukocyte antigen (HLA), remains elusive. The major histocompatibility complex (MHC) class I MICA gene is a candidate histocompatibility locus. Here, we investigate its role in a French multicenter cohort of 1,356 kidney transplants. MICA mismatches were associated with decreased graft survival (hazard ratio (HR), 2.12; 95% confidence interval (CI): 1.45-3.11; P < 0.001). Both before and after transplantation anti-MICA donor-specific antibodies (DSA) were strongly associated with increased antibody-mediated rejection (ABMR) (HR, 3.79; 95% CI: 1.94-7.39; P < 0.001; HR, 9.92; 95% CI: 7.43-13.20; P < 0.001, respectively). This effect was synergetic with that of anti-HLA DSA before and after transplantation (HR, 25.68; 95% CI: 3.31-199.41; P = 0.002; HR, 82.67; 95% CI: 33.67-202.97; P < 0.001, respectively). De novo-developed anti-MICA DSA were the most harmful because they were also associated with reduced graft survival (HR, 1.29; 95% CI: 1.05-1.58; P = 0.014). Finally, the damaging effect of anti-MICA DSA on graft survival was confirmed in an independent cohort of 168 patients with ABMR (HR, 1.71; 95% CI: 1.02-2.86; P = 0.041). In conclusion, assessment of MICA matching and immunization for the identification of patients at high risk for transplant rejection and loss is warranted.


Asunto(s)
Trasplante de Riñón , Rechazo de Injerto/genética , Supervivencia de Injerto/genética , Antígenos de Histocompatibilidad Clase I/genética , Humanos
10.
Plants (Basel) ; 10(9)2021 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-34579412

RESUMEN

Pectobacterium parmentieri is a plant-pathogenic bacterium, recently attributed as a separate species, which infects potatoes, causing soft rot in tubers. The distribution of P. parmentieri seems to be global, although the bacterium tends to be accommodated to moderate climates. Fast and accurate detection systems for this pathogen are needed to study its biology and to identify latent infection in potatoes and other plant hosts. The current paper reports on the development of a specific and sensitive detection protocol based on a real-time PCR with a TaqMan probe for P. parmentieri, and its evaluation. In sensitivity assays, the detection threshold of this protocol was 102 cfu/mL on pure bacterial cultures and 102-103 cfu/mL on plant material. The specificity of the protocol was evaluated against P. parmentieri and more than 100 strains of potato-associated species of Pectobacterium and Dickeya. No cross-reaction with the non-target bacterial species, or loss of sensitivity, was observed. This specific and sensitive diagnostic tool may reveal a wider distribution and host range for P. parmentieri and will expand knowledge of the life cycle and environmental preferences of this pathogen.

11.
Plants (Basel) ; 10(2)2021 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-33668425

RESUMEN

The recent taxonomic diversification of bacterial genera Pectobacterium and Dickeya, which cause soft rot in plants, focuses attention on the need for improvement of existing methods for the detection and differentiation of these phytopathogens. This research presents a whole genome-based approach to the selection of marker sequences unique to particular species of Pectobacterium. The quantitative real-time PCR assay developed is selective in the context of all tested Pectobacterium atrosepticum strains and is able to detect fewer than 102 copies of target DNA per reaction. The presence of plant DNA extract did not affect the sensitivity of the assay.

12.
Structure ; 29(1): 15-28.e7, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-33053321

RESUMEN

The SRP54 GTPase is a key component of co-translational protein targeting by the signal recognition particle (SRP). Point mutations in SRP54 have been recently shown to lead to a form of severe congenital neutropenia displaying symptoms overlapping with those of Shwachman-Diamond syndrome. The phenotype includes severe neutropenia, exocrine pancreatic deficiency, and neurodevelopmental as well as skeletal disorders. Using a combination of X-ray crystallography, hydrogen-deuterium exchange coupled to mass spectrometry and complementary biochemical and biophysical methods, we reveal extensive structural defects in three disease-causing SRP54 variants resulting in critical protein destabilization. GTP binding is mostly abolished as a consequence of an altered GTPase core. The mutations located in conserved sequence fingerprints of SRP54 eliminate targeting complex formation with the SRP receptor as demonstrated in yeast and human cells. These specific defects critically influence the entire SRP pathway, thereby causing this life-threatening disease.


Asunto(s)
Síndromes Congénitos de Insuficiencia de la Médula Ósea/genética , Mutación , Neutropenia/congénito , Partícula de Reconocimiento de Señal/química , Sitios de Unión , Guanosina Trifosfato/metabolismo , Células HEK293 , Humanos , Neutropenia/genética , Unión Proteica , Estabilidad Proteica , Transporte de Proteínas , Partícula de Reconocimiento de Señal/genética , Partícula de Reconocimiento de Señal/metabolismo
13.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 76(Pt 1): 28-37, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32831237

RESUMEN

A new triple tungstate Rb9-xAg3+xSc2(WO4)9 (0 ≤ x ≤ 0.15) synthesized by solid state reactions and spontaneous crystallization from melts presents a new structure type related to those of Cs7Na5Yb2(MoO4)9 and Na13Sr2Ta2(PO4)9. The title compound in centrosymmetric space group Cmcm contains dimers of two ScO6 octahedra sharing corners with three bridging WO4 tetrahedra. Three pairs of opposite terminal WO4 tetrahedra are additionally linked by AgO2 dumbbells to form {Ag3[Sc2(WO4)9]}9- groups, which together with some rubidium ions are packed in pseudohexagonal glaserite-like layers parallel to (001), but stacking of the layers is different in these three structures. In the title structure, the layers stack with a shift along the b axis and their interlayer space contains disordered Rb+ cations partially substituted by Ag+ ions. Almost linear chains of incompletely filled close Rb3a-Rb3d positions (the shortest distances Rb-Rb are 0.46 to 0.64 Å) are found to locate approximately along the b axis. This positional disorder and the presence of wide common quadrangular faces of Rb2 and Rb3a-Rb3d coordination polyhedra favor two-dimensional ionic conductivity in the (001) plane with Rb+ and Ag+ carriers, which was confirmed with bond valence sum (BVS) maps. Electrical conductivity measurements on Rb9Ag3Sc2(WO4)9 ceramics revealed a first-order superionic phase transition at 570 K with a sharp increase in the electrical conductivity. The conductivity σi = 1.8 × 10-3 S cm-1 at 690 K is comparable with the value of 1.0 × 10-3 S cm-1 (500 K) observed earlier for rubidium-ion transport in pyrochlore-like ferroelectric RbNbWO6.

14.
Bone Marrow Transplant ; 55(7): 1367-1378, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32286503

RESUMEN

Graft-versus-host disease (GVHD) and cytomegalovirus (CMV)-related complications are leading causes of mortality after unrelated-donor hematopoietic cell transplantation (UD-HCT). The non-conventional MHC class I gene MICB, alike MICA, encodes a stress-induced polymorphic NKG2D ligand. However, unlike MICA, MICB interacts with the CMV-encoded UL16, which sequestrates MICB intracellularly, leading to immune evasion. Here, we retrospectively analyzed the impact of mismatches in MICB amino acid position 98 (MICB98), a key polymorphic residue involved in UL16 binding, in 943 UD-HCT pairs who were allele-matched at HLA-A, -B, -C, -DRB1, -DQB1 and MICA loci. HLA-DP typing was further available. MICB98 mismatches were significantly associated with an increased incidence of acute (grade II-IV: HR, 1.20; 95% CI, 1.15 to 1.24; P < 0.001; grade III-IV: HR, 2.28; 95% CI, 1.56 to 3.34; P < 0.001) and chronic GVHD (HR, 1.21; 95% CI, 1.10 to 1.33; P < 0.001). MICB98 matching significantly reduced the effect of CMV status on overall mortality from a hazard ratio of 1.77 to 1.16. MICB98 mismatches showed a GVHD-independent association with a higher incidence of CMV infection/reactivation (HR, 1.84; 95% CI, 1.34 to 2.51; P < 0.001). Hence selecting a MICB98-matched donor significantly reduces the GVHD incidence and lowers the impact of CMV status on overall survival.


Asunto(s)
Infecciones por Citomegalovirus , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Aminoácidos , Infecciones por Citomegalovirus/epidemiología , Infecciones por Citomegalovirus/prevención & control , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/prevención & control , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Incidencia , Estudios Retrospectivos
15.
Appl Biochem Biotechnol ; 119(1): 31-40, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15496726

RESUMEN

The toxicity potential and decolorization of three acid azo dyes (Acid Orange 6, Acid Orange 7, and Acid Orange 52) by methanogenic granular sludge from an anaerobic expanded granular sludge bed reactor was assayed. Complete bioreduction was found for all three azo dyes. Sulfanilic acid and 4-aminoresorcinol were detected from the decolorization of Acid Orange 6, sulfanilic acid and 1-amino-2-naphtol were detected from the reduction of Acid Orange 7, and sulfanilic acid and N,N-dimethyl-1,4-phenylenediamine (DMP) were found to be intermediates of Acid Orange 52 degradation. Sulfanilic acid and 1-amino-2-naphtol were persistent in the anaerobic conditions, whereas 4-aminoresorcinol was completely mineralized by anaerobic sludge and DMP was transformed into 1,4-phenylenediamine. Enrichment cultures obtained via consecutive passages on basal medium with only azo dye as a carbon and an energy source seemed to be morphologically heterogeneous. Baculiform and coccus cells were found when viewed under a light microscope. Cocci were joined in chains. Because anaerobic sludge contains sulfate-reducing bacteria and therefore may generate sulfide, azo dyes were tested for chemical decolorization by sulfide to compare rates of chemical and biologic reduction.


Asunto(s)
Compuestos Azo/metabolismo , Bacterias Anaerobias/metabolismo , Colorantes/metabolismo , Compuestos Azo/química , Compuestos Azo/toxicidad , Color , Colorantes/química , Colorantes/toxicidad , Residuos Industriales , Estructura Molecular , Oxidación-Reducción , Sulfuros/química , Sulfuros/metabolismo , Eliminación de Residuos Líquidos
16.
Mol Cancer Ther ; 10(9): 1611-23, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21697397

RESUMEN

TNF-related apoptosis-inducing ligand (TRAIL) kills tumor cells selectively. We asked how emerging tumor cells escape elimination by TRAIL and how tumor-specific killing by TRAIL could then be restored. We found that TRAIL expression is consistently downregulated in HRAS(G12V)-transformed cells in stepwise tumorigenesis models derived from four different tissues due to DNA hypermethylation of CpG clusters within the TRAIL promoter. Decitabine de-silenced TRAIL, which remained inducible by interferon, while induction of TRAIL by blocking the HRAS(G12V)-activated mitogen-activated protein kinase pathway was subordinated to epigenetic silencing. Decitabine induced apoptosis through upregulation of endogenous TRAIL in cooperation with favorable regulation of key players acting in TRAIL-mediated apoptosis. Apoptosis induction by exogenously added TRAIL was largely increased by decitabine. In vivo treatment of xenografted human HRAS(G12V)-transformed human epithelial kidney or syngenic mice tumors by decitabine blocked tumor growth induced TRAIL expression and apoptosis. Our results emphasize the potential of decitabine to enhance TRAIL-induced apoptosis in tumors and thus provide a rationale for combination therapies with decitabine to increase tumor-selective apoptosis.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Azacitidina/análogos & derivados , Transformación Celular Neoplásica/genética , Metilación de ADN/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Silenciador del Gen , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Animales , Antimetabolitos Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Apoptosis/genética , Azacitidina/farmacología , Azacitidina/uso terapéutico , Línea Celular Transformada , Línea Celular Tumoral , Decitabina , Regulación hacia Abajo/genética , Inhibidores Enzimáticos/uso terapéutico , Epigénesis Genética , Regulación de la Expresión Génica/efectos de los fármacos , Células HeLa , Humanos , Interferones/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Transducción de Señal , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
17.
Arch Microbiol ; 181(2): 163-70, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14716473

RESUMEN

Following incubation of mesophilic methanogenic floccular sludge from a lab-scale upflow anaerobic sludge bed reactor used to treat cattle manure wastewater, a stable 5-aminosalicylate-degrading enrichment culture was obtained. Subsequently, a Citrobacter freundii strain, WA1, was isolated from the 5-aminosalicylate-degrading methanogenic consortium. The methanogenic enrichment culture degraded 5-aminosalicylate completely to CH4, CO2 and NH4+, while C. freundii strain WA1 reduced 5-aminosalicylate with simultaneous deamination to 2-hydroxybenzyl alcohol during anaerobic growth with electron donors such as pyruvate, glucose or serine. When grown on pyruvate, C. freundii WA1 converted 3-aminobenzoate to benzyl alcohol and also reduced benzaldehyde to benzyl alcohol. Pyruvate was fermented to acetate, CO2, H2 and small amounts of lactate, succinate and formate. Less lactate (30%) was produced from pyruvate when C. freundii WA1 grew with 5-aminosalicylate as co-substrate.


Asunto(s)
Citrobacter freundii/aislamiento & purificación , Citrobacter freundii/metabolismo , Hidrocarburos Aromáticos/metabolismo , Amoníaco/metabolismo , Anaerobiosis , Benzaldehídos/metabolismo , Alcohol Bencilo/metabolismo , Biodegradación Ambiental , Reactores Biológicos , Dióxido de Carbono/metabolismo , Ácidos Carboxílicos/metabolismo , Citrobacter freundii/clasificación , Citrobacter freundii/citología , ADN Ribosómico/química , ADN Ribosómico/aislamiento & purificación , Glucosa/metabolismo , Hidrógeno/metabolismo , Cinética , Mesalamina/metabolismo , Metano/metabolismo , Datos de Secuencia Molecular , Serina/metabolismo , Aguas del Alcantarillado/microbiología
18.
Eur J Biochem ; 270(8): 1791-801, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12694192

RESUMEN

Ribonucleotide reductase is essential for the synthesis of all four dNTPs required for DNA replication. The enzyme is composed of two proteins, R1 and R2, which are both needed for activity. Expression of the R1 and R2 mRNAs is restricted to the S-phase of the cell cycle, but the R1 and R2 promoters show no obvious sequence homologies that could indicate coordination of transcription. Here we study initiation of transcription at the natural mouse R2 promoter, which contains an atypical TATA-box with the sequence TTTAAA, using a combination of in vivo reporter gene assays and in vitro transcription. Our results indicate that in constructs where sequences from the R2 5'-UTR are present, the mouse R2 TATA-box is dispensable both for unregulated, basal transcription from the R2 promoter and for S-phase specific activity. Instead, initiation of R2 transcription is directed by sequences downstream from the transcription start. We report that this region contains a conserved palindrome sequence that interacts with TAFIIs. This interaction down-regulates basal transcription from the R2 promoter, both in the absence and in the presence of the TATA-box.


Asunto(s)
Ribonucleótido Reductasas/química , Ribonucleótido Reductasas/metabolismo , Transcripción Genética , Regiones no Traducidas 5'/genética , Animales , Secuencia de Bases , Núcleo Celular/enzimología , Cartilla de ADN , Replicación del ADN , Genes Reporteros , Humanos , Cinética , Ratones , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Proteínas Recombinantes/metabolismo , Ribonucleótido Reductasas/genética , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , TATA Box
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