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BACKGROUND: DNA methylation forms 5-methylcytosine and its regulation in the hippocampus is critical for learning and memory. Indeed, dysregulation of DNA methylation is associated with neurological diseases. Alzheimer's disease (AD) is the predominant of dementia and a neurodegenerative disorder. METHODS: We examined the learning and memory function in 3- and 9-month-old wild-type and 5xfamiliar Alzheimer's disease (5xFAD) transgenic mice by performing the object recognition memory and Y-maze tests, and identified the hippocampal amyloid beta burden. To investigate the epigenetically regulated genes involved in the development or neuropathology of AD, we performed genome-wide DNA methylation sequencing and RNA sequencing analyses in the hippocampus of 9-month-old wild-type and 5xFAD tg mice. To validate the genes inversely regulated by epigenetics, we confirmed their methylation status and mRNA levels. RESULTS: At 9 months of age, 5xFAD tg mice showed significant cognitive impairment and amyloid-beta plaques in the hippocampus. DNA methylation sequencing identified a total of 13,777 differentially methylated regions, including 4484 of hyper- and 9293 of hypomethylated regions, that are associated with several gene ontology (GO) terms including 'nervous system development' and 'axon guidance'. In RNA sequencing analysis, we confirmed a total of 101 differentially expressed genes, including 52 up- and 49 downregulated genes, associated with GO functions such as 'positive regulation of synaptic transmission, glutamatergic' and 'actin filament organization'. Through further integrated analysis of DNA methylation and RNA sequencing, three epigenetically regulated genes were selected: thymus cell antigen 1, theta (Thy1), myosin VI (Myo6), and filamin A-interacting protein 1-like (Filip1l). The methylation level of Thy1 decreased and its mRNA levels increased, whereas that of Myo6 and Filip1l increased and their mRNA levels decreased. The common functions of these three genes may be associated with the neural cytoskeleton and synaptic plasticity. CONCLUSIONS: We suggest that the candidate genes epigenetically play a role in AD-associated neuropathology (i.e., amyloid-beta plaques) and memory deficit by influencing neural structure and synaptic plasticity. Furthermore, counteracting dysregulated epigenetic changes may delay or ameliorate AD onset or symptoms.
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Enfermedad de Alzheimer , Metilación de ADN , Modelos Animales de Enfermedad , Hipocampo , Ratones Transgénicos , Animales , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Hipocampo/metabolismo , Ratones , Expresión Génica , Epigénesis Genética , Estudio de Asociación del Genoma Completo , Masculino , Humanos , Ratones Endogámicos C57BLRESUMEN
Although there are several types of radiation exposure, it is debated whether lowdoserate (LDR) irradiation (IR) affects the body. Since the small intestine is a radiationsensitive organ, the present study aimed to evaluate how it changes when exposed to LDR IR and identify the genes sensitive to these doses. After undergoing LDR (6.0 mGy/h) γ radiation exposure, intestinal RNA from BALB/c mice was extracted 1 and 24 h later. Mouse whole genome microarrays were used to explore radiationinduced transcriptional alterations. Reverse transcriptionquantitative (RTq) PCR was used to examine time and dosedependent radiation responses. The histopathological status of the jejunum in the radiated mouse was not changed by 10 mGy of LDR IR; however, 23 genes were upregulated in response to LDR IR of the jejunum in mice after 1 and 24 h of exposure. Upregulated genes were selected to validate the results of the RNA sequencing analysis for RTqPCR detection and results showed that only Na+/K+ transporting subunit α4, glucose6phosphatase catalytic subunit 2 (G6PC2), mucin 6 (MUC6) and transient receptor potential cation channel subfamily V member 6 levels significantly increased after 24 h of LDR IR. Furthermore, G6PC2 and MUC6 were notable genes induced by LDR IR exposure according to protein expression via western blot analysis. The mRNA levels of G6PC2 and MUC6 were significantly elevated within 24 h under three conditions: i) Exposure to LDR IR, ii) repeated exposure to LDR IR and iii) exposure to LDR IR in the presence of inflammatory bowel disease. These results could contribute to an improved understanding of immediate radiation reactions and biomarker development to identify radiationsusceptible individuals before histopathological changes become noticeable. However, further investigation into the specific mechanisms involving G6PC2 and MUC6 is required to accomplish this.
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Glucosa-6-Fosfatasa , Enfermedades Inflamatorias del Intestino , Mucina 6 , Animales , Masculino , Ratones , Relación Dosis-Respuesta en la Radiación , Rayos gamma/efectos adversos , Glucosa-6-Fosfatasa/metabolismo , Glucosa-6-Fosfatasa/genética , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Enfermedades Inflamatorias del Intestino/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de la radiación , Mucosa Intestinal/patología , Intestinos/efectos de la radiación , Intestinos/patología , Yeyuno/efectos de la radiación , Yeyuno/metabolismo , Yeyuno/patología , Ratones Endogámicos BALB C , Mucina 6/metabolismo , Mucina 6/genéticaRESUMEN
Scrophularia have traditionally been used as herbal medicines to treat neuritis, sore throats, and laryngitis. In particular, S. takesimensis, a Korean endemic species with restricted distribution on Ulleung Island, holds significant resource and genetic value. However, its pharmacological properties have not been thoroughly evaluated. Thus, we provide detailed morphological characteristics and genomic information for S. takesimensis in this study. Moreover, its pharmacological activity was evaluated in an ovalbumin-induced asthma rat model, using extracts of S. takesimensis roots (100 or 200 mg/kg). The distinguishing features of S. takesimensis from related species include the presence or absence of stem wings, leaf shape, and habitat. The chloroplast (cp) genome of this species is 152,420 bp long and exhibits a conserved quadripartite structure. A total of 114 genes were identified, which included 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and 4 ribosomal RNA (rRNA) genes. The gene order, content, and orientation of the S. takesimensis cp genome was highly conserved and consistent with the general structure observed in S. buergeriana and S. ningpoensis cp genomes. Confirming the anti-inflammatory effects of S. takesimensis extract (STE) using an established mouse model of ovalbumin-induced asthma, we observed reduced asthmatic phenotypes, including inflammatory cell infiltration, mucus production, and suppression of T helper 2 (Th2) cell. Furthermore, STE treatment reduced Th2 cell activation and differentiation. This study underscores the medicinal value of S. takesimensis. The importance of preserving S. takesimensis was revealed and crucial insights were provided for further research on its utilization as a medicinal resource.
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Scutellaria baicalensis Georgi and Raphanus Sativus Linne herbal mixture (SRE) is a Chinese herbal medicine. In this study, we aimed to evaluate the therapeutic efficacy of SRE as an active ingredient for 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) and to predict the underlying therapeutic mechanisms and involved pathways using network pharmacological analysis. Treatment with SRE accelerated the development of AD-like lesions, improving thickness and edema of the epidermis. Moreover, administering the SRE to AD-like mice suppressed immunoglobulin E and interleukin-4 cytokine and reduced T lymphocyte differentiation. In silico, network analysis was used to predict the exact genes, proteins, and pathways responsible for the therapeutic effect of the SRE against DNCB-induced AD. These results indicated that the SRE exerted protective effects on the DNCB-induced AD-like model by attenuating histopathological changes and suppressing the levels of inflammatory mediators. Therefore, the SRE can potentially be a new remedy for improving AD and other inflammatory diseases and predicting the intracellular signaling pathways and target genes involved. This therapeutic effect of the SRE on AD can be used to treat DNCB-induced AD and its associated symptoms.
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Interleukin-2 (IL-2) induces contrasting immune responses depending on its binding receptor subunit; thus, selective receptor binding is considered a key challenge in cancer therapeutic strategies. In this study, we aimed to investigate the inhibition of IL-2 action and antitumor activity of celastrol (CEL), a compound identified in a screen for IL-2/CD25 binding inhibitors, and to elucidate the underlying role of CEL in immune cells. We found that CEL selectively impairs the binding of IL-2 and CD25 and directly binds to IL-2 but not to CD25. CEL significantly suppressed the proliferation and signaling of IL-2-dependent murine T cells and interfered with IL-2-responsive STAT5 phosphorylation in IL-2 reporter cells and human PBMCs. After confirming the impact of CEL on IL-2, we evaluated its antitumor activity in C57BL/6 mice bearing B16F10 tumors and found that CEL significantly inhibited tumor growth by increasing CD8+ T cells. We also found that CEL did not inhibit tumor growth in T cell-deficient BALB/c nude mice, suggesting that its activity was mediated by the T-cell response. Moreover, combination therapy with low-dose CEL and a TNFR2 antagonist synergistically improved the therapeutic efficacy of the individual monotherapies by increasing the ratio of intratumoral CD8/Treg cells and suppressing Foxp3 expression. These findings suggest that CEL, which inhibits CD25 binding by targeting IL-2, exerts antitumor activity by mediating the T-cell response and could be a promising candidate for combination therapy in cancer immunotherapy against melanoma.
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Melanoma , Humanos , Ratones , Animales , Melanoma/tratamiento farmacológico , Melanoma/patología , Interleucina-2 , Linfocitos T CD8-positivos/metabolismo , Ratones Desnudos , Ratones Endogámicos C57BL , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Linfocitos T ReguladoresRESUMEN
Asthma is a pulmonary disease induced by the inhalation of aeroallergens and subsequent inappropriate immune responses. Camellia sinensis (L.) Kuntze has been evaluated as an effective antioxidant supplement produced from bioactive compounds, including flavonoids. In this study, we aimed to determine the effects of Camellia sinensis (L.) Kuntze extract (CE) on ovalbumin-induced allergic asthma. The components of CE were analyzed using high-performance liquid chromatography (HPLC) chromatogram patterns, and asthmatic animal models were induced via ovalbumin treatment. The antioxidant and anti-inflammatory effects of CE were evaluated using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), and nitric oxide (NO) assays. Seven compounds were detected in the CE chromatogram. In the ovalbumin-induced mouse model, CE treatment significantly decreased the inflammation index in the lung tissue. CE also significantly decreased eosinophilia and the production of inflammatory cytokines and OVA-specific IgE in animals with asthma. Collectively, our results indicate that CE has anti-inflammatory and antioxidant activities, and that CE treatment suppresses asthmatic progression, including mucin accumulation, inflammation, and OVA-specific IgE production.
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Flavonoids are a major component of Ginkgo biloba extract (GBE). Several studies have investigated chelate formation and the redox reaction between flavonoids and metal ions; however, the effect of mineral supplements on the results from the analysis of the flavonol glycoside content in products containing GBE dietary supplement remains unknown. In this study, the effects of commonly used mineral supplements on the recovery of quercetin from GBE-containing dietary supplements were investigated using conventional methods of flavonol glycoside determination. Mineral supplements containing Zn (II), Mn (II), and Fe (II) did not affect quercetin recovery, whereas Cu (II) and Fe (III) significantly reduced recovery (P<0.05). Quercetin oxidation was prevented by adding an antioxidant to the diluent (extraction solvent). Among the tested synthetic antioxidants, tert-butyl hydroquinone (TBHQ) promoted the greatest increase in quercetin recovery. The flavonol glycoside content of commercially available GBE-containing dietary supplements was analyzed using a conventional diluent or a diluent containing 20 mg/mL TBHQ. The amount of quercetin recovered from products containing Cu (II) was found to decrease with increasing hydrolysis duration and the duration in the final test solution state using the conventional diluent, while the TBHQ-containing diluent yielded consistent quercetin contents (P<0.05). These findings suggest that quercetin, a major aglycone of GBE flavonol glycosides, can be oxidized by Cu (II) and Fe (III) during the analytical process and, therefore, the total flavonol glycoside content may be underestimated. The addition of TBHQ to the diluent can improve the accuracy and reproducibility of flavonol glycoside content analysis in GBE-containing dietary products supplemented with minerals.
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Poly (aspartic acid sodium salt) (PAspNa) was evaluated for its potential as a novel draw solute in forward osmosis (FO). The inherent advantages of PAspNa, such as good water solubility, high osmotic pressure, and nontoxicity, were first examined through a series of physicochemical analyses and atomic-scale molecular dynamics simulations. Then, lab-scale FO tests were performed to evaluate its suitability in practical processes. Compared to other conventional inorganic solutes, PAspNa showed comparable water flux but significantly lower reverse solute flux, demonstrating its suitability as a draw solute. Moreover, fouling experiments using synthetic wastewater as a feed solution demonstrated that PAspNa reversely flowed to the feed side reduced inorganic scaling on the membrane active layer. The recyclability of PAspNa was studied using both nanofiltration (NF) and membrane distillation (MD) processes, and the results exhibited its ease of recovery. This research reported the feasibility and applicability of FO-NF or FO-MD processes using PAspNa for wastewater reclamation and brackish water desalination.
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Ácido Aspártico/química , Péptidos/química , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Destilación/instrumentación , Destilación/métodos , Estudios de Factibilidad , Hidrodinámica , Membranas Artificiales , Ósmosis , Presión Osmótica , Reciclaje , Reproducibilidad de los Resultados , Sodio/química , Solubilidad , Eliminación de Residuos Líquidos/instrumentación , Aguas Residuales/química , Purificación del Agua/instrumentaciónRESUMEN
A novel multiscale porous architecture where an individual particle is nested inside a hollow chamber of inverse-opal (IO) frame is created using a large scale self-assembly of core-shell structured colloidal particles and subsequent selective removal of the outer shells of the colloids. Since the nested particle is smaller than the size of individual IO chamber, the interconnected nanochannels are spontaneously formed within the structured frame. The size of internal nanochannels is readily tuned to have high permeability and size-selective separation capability, which is successfully tested for nanoparticle separation.
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Bacteriófago M13/química , Bacteriófago M13/ultraestructura , Grafito/química , Membranas Artificiales , Nanoestructuras/química , Nanoestructuras/ultraestructura , Ultrafiltración/instrumentación , Adsorción , Bacteriófago M13/fisiología , Polaridad Celular/fisiología , Microfluídica/métodos , Óxidos/química , Tamaño de la Partícula , Ultrafiltración/métodosRESUMEN
The use of forward osmosis (FO) process for seawater desalination has attracted tremendous interest in recent years. Besides the manufacture of suitable membranes, the major technical challenge in the efficient deployment of the FO technology lies in the development of a suitable "draw solute". Owing to its inherent advantages, poly(aspartic acid) has arisen to be an attractive candidate for this purpose. However, an investigation of its molecular level properties has not been studied in detail. In this paper, the dynamics of poly(aspartic acid) and its sodium salt in the dilute concentration regime have been reported. The quantification of the polymer conformational properties, its solvation behavior, and the counterion dynamics are studied. The neutral polymer shows a preferentially coiled structure whereas the fully ionized polymer has an extended structure. Upon comparing with poly(acrylic acid) polymer, another polymer which has been used as a draw solute, poly(aspartic acid) forms more number of hydrogen bonds as well as fewer ion pairs.
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Simulación de Dinámica Molecular , Péptidos/química , Sodio/química , Agua/química , Difusión , Enlace de Hidrógeno , Iones/química , Ósmosis , Sales (Química)/química , Soluciones/químicaRESUMEN
Water soluble and biocompatible iron oxide nanoparticles coated with poly(aspartic acid) (PAsp), poly(asparagines) (PAsn), poly(2-hydroxy-ethyl L-aspartamide) (PHEA), and poly-α,ß-(N-2-dimethylaminoethyl L-aspartamide) (PDMAEA) were prepared by hydrophobic interaction between hydrophobic iron oxide nanoparticles and each amphiphilic poly(amino acid)s graft polymer. The octadecyl side chain grafted poly(succinimide)(PSI-g-C(18)), used as a precursor polymer, was easily aminolyzed with nucleophilic compounds to form various poly(amino acid)s graft polymer (PAsp-g-C(18), PAsn-g-C(18), PHEA-g-C(18), PDMAEA-g-C(18),) and simultaneously stabilize the dispersion of iron oxide nanoparticles in aqueous solution. The diameters of the poly(amino acid)s coated iron oxide nanoparticles (PAIONs) were smaller than 30 nm in aqueous solution, extremely stable in aqueous solutions with a wide range of pH and salt concentrations. Further, all the PAIONs showed excellent MR signal intensities (high r(2) values) and the cellular uptake property of the PAIONs was also evaluated.
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Compuestos Férricos/química , Nanopartículas/química , Péptidos/química , Supervivencia Celular , Compuestos Férricos/farmacología , Humanos , Células KB , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Nanopartículas/ultraestructura , Péptidos/farmacología , Fantasmas de Imagen , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de SuperficieRESUMEN
We present a photopolymeric multifunctional dendrimer for holographic applications. In this study, we described a synthesis of multiphotoreactive dendrimer and phase compatible polymer matrix as well as a numerical simulation of the dendrimer. This holographic photopolymer containing a nanosized photoreactive organic dendrimer could address the aggregation issue of conventional inorganic nanoparticle additives and allowed writing-induced shrinkage to be successfully reduced to the extent of acceptable values for 130 µm thick film. In this report, holographic performance including diffraction efficiency (DE), transmission, photosensitivity, modulation of refractive index, polarization sensitivity, and volume shrinkage has been discussed. The page-wise recording by using an amplitude spatial light modulator (SLM) was also demonstrated.
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We describe a signal amplified biosensor based on self-assembled optical diffraction grating of a Fresnel zone plate structure. Diffracted light rays passed through gratings are interfered constructively at the focal point, resulting in the enhanced signal amplification without sacrificing signal-to-noise ratio (SNR).
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Biodegradable polymeric microneedles were developed as a method for achieving sustained transdermal drug release. These microneedles have potential as a patient-friendly substitute for conventional sustained release methods. However, they have limitations related to the difficulty of achieving separation of the needles into the skin. We demonstrated that microneedle separation into the skin was mediated by hydrogel swelling in response to contact with body fluid after the needles were inserted into the skin. The hydrogel microparticles were synthesized by an emulsification method using poly-N-isopropylacrylamide (PNIPAAm). The microneedles were fabricated by micromolding poly-lactic-co-glycolic acid (PLGA) after filling the cavities of the mold with the hydrogel microparticles. The failure of microneedle tips caused by hydrogel swelling was studied in regard to contact with water, insertion of microneedles into porcine cadaver skin in vitro, stress-strain behavior, and insertion into the back skin of a hairless mouse in vivo. The drug delivery property of the hydrogel particles was investigated qualitatively by inserting polymer microneedles into porcine cadaver skin in vitro, and the sustained release property of PLGA microneedles containing hydrogel microparticles was studied quantitatively using the Franz cell model. The hydrogel particles absorbed water quickly, resulting in the cracking of the microneedles due to the difference in volume expansion between the needle matrix polymer and the hydrogel particles. The swollen particles caused the microneedles to totally breakdown, leaving the microneedle tips in the porcine cadaver skin in vitro and in the hairless mouse skin in vivo. Model drugs encapsulated in biodegradable polymer microneedles and hydrogel microparticles were successfully delivered by releasing microneedles into the skin.
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Implantes Absorbibles , Sistemas de Liberación de Medicamentos/métodos , Hidrogeles/administración & dosificación , Polímeros/química , Piel/metabolismo , Resinas Acrílicas/metabolismo , Administración Cutánea , Animales , Fenómenos Químicos , Preparaciones de Acción Retardada , Diseño de Equipo , Hidrogeles/metabolismo , Ácido Láctico/metabolismo , Ratones , Microinyecciones/métodos , Agujas , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , PorcinosRESUMEN
We present a new blue-sensitized photopolymer to achieve a higher storage density compared to green/red-recordable media. Photopolymers are prepared based on a two-chemistry system and their holographic recording properties are investigated. A matrix of long and flexible ether units of an epoxy precursor and a multi-crosslinkable amine hardener enhances energetic sensitivity and suppresses volume shrinkage effectively. Page-wise recording of 961 bits/page of digital data is demonstrated and long term recording stability is also verified for a period of roughly 2 months.
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Holografía/métodos , Almacenamiento y Recuperación de la Información/métodos , Rayos Láser , Luz , Polímeros/química , Simulación por Computador , Factores de Tiempo , Rayos UltravioletaRESUMEN
BACKGROUND: Vascular endothelial growth factor A (VEGFA), a critical mediator of tumor angiogenesis, is a well-characterized target of hypoxia-inducible factor 1 (HIF-1). Murine arrest-defective protein 1A (mARD1A(225)) acetylates HIF-1alpha, triggering its degradation, and thus may play a role in decreased expression of VEGFA. METHODS: We generated Apc(Min/+)/mARD1A(225) transgenic mice and quantified growth of intestinal polyps. Human gastric MKN74 and murine melanoma B16F10 cells overexpressing mARD1A(225) were injected into mice, and tumor growth and metastasis were measured. VEGFA expression and microvessel density in tumors were assessed using immunohistochemistry. To evaluate the role of mARD1A(225) acetylation of Lys532 in HIF-1alpha, we injected B16F10-mARD1A(225) cell lines stably expressing mutant HIF-1alpha/K532R into mice and measured metastasis. All statistical tests were two-sided, and P values less than .05 were considered statistically significant. RESULTS: Apc(Min/+)/mARD1A(225) transgenic mice (n = 25) had statistically significantly fewer intestinal polyps than Apc(Min/+) mice (n = 21) (number of intestinal polyps per mouse: Apc(Min/+) mice vs Apc(Min/+)/mARD1A(225) transgenic mice, mean = 83.4 vs 38.0 polyps, difference = 45.4 polyps, 95% confidence interval [CI] = 41.8 to 48.6; P < .001). The growth and metastases of transplanted tumors were also statistically significantly reduced in mice injected with mARD1A(225)-overexpressing cells than in mice injected with control cells (P < .01). Moreover, overexpression of mARD1A(225) decreased VEGFA expression and microvessel density in tumor xenografts (P < .04) and Apc(Min/+) intestinal polyps (P = .001). Mutation of lysine 532 of HIF-1alpha in B16F10-mARD1A(225) cells prevented HIF-1alpha degradation and inhibited the antimetastatic effect of mARD1A(225) (P < .001). CONCLUSION: mARD1A(225) may be a novel upstream target that blocks VEGFA expression and tumor-related angiogenesis.
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Acetiltransferasas/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Pólipos Intestinales/metabolismo , Pólipos Intestinales/patología , Neovascularización Patológica/metabolismo , Neovascularización Patológica/prevención & control , Acetilación , Animales , Western Blotting , Línea Celular Tumoral , Regulación hacia Abajo , Ensayo de Inmunoadsorción Enzimática , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Inmunohistoquímica , Inmunoprecipitación , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundario , Lisina , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Ratones Transgénicos , Microcirculación , Mutación , Acetiltransferasa A N-Terminal , Acetiltransferasa E N-Terminal , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia Arriba , Factor A de Crecimiento Endotelial Vascular/análisisRESUMEN
Histone deacetylase inhibitors (HDACIs) are currently in clinical trials partly due to their potent anti-angiogenic effects. However, the detailed mechanism of their action is unclear. Here, we observed that several HDACIs (TSA, SB, Apicidin, and VPA) dramatically decreased HIF-1alpha protein level and transcriptional activity of HIF-1 in human and mouse tumor cell lines. Furthermore, class I HDACs, HDAC1 and 3 enhanced HIF-1alpha stability and HIF-1 transactivation function in hypoxic conditions. In addition, immunoprecipitation and in vitro binding assays revealed that HDAC1 and 3 directly bind to the oxygen-dependent degradation domain of HIF-1alpha. Collectively, these results suggest that HDAC1 and 3 are considered as a positive regulator of HIF-1alpha stability via direct interaction and may play an important role in HIF-1-induced tumor angiogenesis.
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Inhibidores Enzimáticos/farmacología , Inhibidores de Histona Desacetilasas , Histona Desacetilasas/efectos de los fármacos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Animales , Western Blotting , Línea Celular Tumoral , Células HeLa , Humanos , Ácidos Hidroxámicos/farmacología , Subunidad alfa del Factor 1 Inducible por Hipoxia/efectos de los fármacos , Inmunoprecipitación , Ratones , Péptidos Cíclicos/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Activación Transcripcional/efectos de los fármacos , Ácido Valproico/farmacologíaRESUMEN
Metastasis-associated protein 1 (MTA1) is highly upregulated in cancer cells with metastatic potential; however, the molecular mechanism by which MTA1 increases the metastatic potential of cancer cells is unknown. We characterized the functional consequences of MTA1 overexpression in cancer cells with an emphasis on its potential role as a deacetylator of hypoxia-inducible factor-1alpha (HIF-1alpha). MTA1 increased the expression of HIF-1alpha protein, but did not increase the expression of its mRNA. Glutathione S-transferase pull-down and coimmunoprecipitation assays demonstrated direct interaction of MTA1 with HIF-1alpha both in vitro and in vivo. Immunoprecipitation and acetylation assays also showed that MTA1 has deacetylation activity on HIF-1alpha in vivo. Moreover, MTA1 increased the transcriptional activity of HIF-1alpha and enhanced the expression of vascular endothelial growth factor, a target molecule of HIF-1alpha. Conditioned medium collected from MTA1 transfectants also increased angiogenesis in vitro and in vivo, probably through enhanced HIF-1alpha stabilization. These results indicate that MTA1 enhances angiogenesis by stabilization of the HIF-1alpha protein, which is closely related to the increased metastatic potential of cancer cells with high MTA1 expression.
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Histona Desacetilasas/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Neovascularización Patológica , Proteínas Represoras/metabolismo , Línea Celular Tumoral , Colágeno/química , Medios de Cultivo Condicionados/metabolismo , Medios de Cultivo Condicionados/farmacología , Combinación de Medicamentos , Glutatión Transferasa/metabolismo , Humanos , Inmunoprecipitación , Laminina/química , Metástasis de la Neoplasia , Proteoglicanos/química , Transactivadores , Transcripción Genética , Activación TranscripcionalRESUMEN
Mouse ARD1 (mARD1) has been reported to negatively regulate the hypoxia-inducible factor 1alpha (HIF-1alpha) protein by acetylating a lysine residue and enhancing HIF-1alpha ubiquitination and degradation. However, it was recently reported that human ARD1 (hARD1) does not affect HIF-1alpha stability. To further explore the activities of the two orthologs, three mouse (mARD1(198), mARD1(225), mARD1(235)) and two human (hARD1(131), hARD1(235)) variants were identified and characterized. Among these, mARD1(225) was previously reported as a novel negative regulator of HIF-1alpha. Amino acid sequence analysis showed that the C-terminal region (aa 158-225) of mARD1(225) completely differs from those of mouse and human ARD1(235), although all three proteins share a well-conserved N-acetyltransferase domain (aa 45-130). The effects of ARD1 variants were evaluated with respect to HIF-1alpha stability and acetylation activity. Interestingly, mARD1(225) strongly decreased the level of HIF-1alpha and increased the extent of acetylation, whereas mARD1(235) and hARD1(235) variants had a much weaker effect on HIF-1alpha stability and acetylation. These results suggest that ARD1 variants might have different effects on HIF-1alpha stability and acetylation, which may reflect diverse biological functions that remain to be determined.