Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 102
Filtrar
1.
J Biol Chem ; 299(8): 105057, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37468106

RESUMEN

In wild-type phototrophic organisms, carotenoids (Crts) are primarily packed into specific pigment-protein complexes along with (Bacterio)chlorophylls and play important roles in the photosynthesis. Diphenylamine (DPA) inhibits carotenogenesis but not phototrophic growth of anoxygenic phototrophs and eliminates virtually all Crts from photocomplexes. To investigate the effect of Crts on assembly of the reaction center-light-harvesting (RC-LH) complex from the filamentous anoxygenic phototroph Roseiflexus (Rfl.) castenholzii, we generated carotenoidless (Crt-less) RC-LH complexes by growing cells in the presence of DPA. Here, we present cryo-EM structures of the Rfl. castenholzii native and Crt-less RC-LH complexes with resolutions of 2.86 Å and 2.85 Å, respectively. From the high-quality map obtained, several important but previously unresolved details in the Rfl. castenholzii RC-LH structure were determined unambiguously including the assignment and likely function of three small polypeptides, and the content and spatial arrangement of Crts with bacteriochlorophyll molecules. The overall structures of Crt-containing and Crt-less complexes are similar. However, structural comparisons showed that only five Crts remain in complexes from DPA-treated cells and that the subunit X (TMx) flanked on the N-terminal helix of the Cyt-subunit is missing. Based on these results, the function of Crts in the assembly of the Rfl. castenholzii RC-LH complex and the molecular mechanism of quinone exchange is discussed. These structural details provide a fresh look at the photosynthetic apparatus of an evolutionary ancient phototroph as well as new insights into the importance of Crts for proper assembly and functioning of the RC-LH complex.


Asunto(s)
Proteínas Bacterianas , Chloroflexi , Fotosíntesis , Proteínas Bacterianas/metabolismo , Carotenoides/metabolismo , Chloroflexi/metabolismo , Complejos de Proteína Captadores de Luz/química
2.
Nucleic Acids Res ; 50(1): e5, 2022 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-34634809

RESUMEN

Growing evidence suggests that functional cis-regulatory elements (cis-REs) not only exist in epigenetically marked but also in unmarked sites of the human genome. While it is already difficult to identify cis-REs in the epigenetically marked sites, interrogating cis-REs residing within the unmarked sites is even more challenging. Here, we report adapting Reel-seq, an in vitro high-throughput (HTP) technique, to fine-map cis-REs at high resolution over a large region of the human genome in a systematic and continuous manner. Using Reel-seq, as a proof-of-principle, we identified 408 candidate cis-REs by mapping a 58 kb core region on the aging-related CDKN2A/B locus that harbors p16INK4a. By coupling Reel-seq with FREP-MS, a proteomics analysis technique, we characterized two cis-REs, one in an epigenetically marked site and the other in an epigenetically unmarked site. These elements are shown to regulate the p16INK4a expression over an ∼100 kb distance by recruiting the poly(A) binding protein PABPC1 and the transcription factor FOXC2. Downregulation of either PABPC1 or FOXC2 in human endothelial cells (ECs) can induce the p16INK4a-dependent cellular senescence. Thus, we confirmed the utility of Reel-seq and FREP-MS analyses for the systematic identification of cis-REs at high resolution over a large region of the human genome.


Asunto(s)
Mapeo Cromosómico/métodos , Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Secuencias Reguladoras de Ácidos Nucleicos , Regulación de la Expresión Génica , Humanos
3.
J Integr Plant Biol ; 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38411333

RESUMEN

Halorhodospira (Hlr.) halochloris is a triply extremophilic phototrophic purple sulfur bacterium, as it is thermophilic, alkaliphilic, and extremely halophilic. The light-harvesting-reaction center (LH1-RC) core complex of this bacterium displays an LH1-Qy transition at 1,016 nm, which is the lowest-energy wavelength absorption among all known phototrophs. Here we report the cryo-EM structure of the LH1-RC at 2.42 Å resolution. The LH1 complex forms a tricyclic ring structure composed of 16 αßγ-polypeptides and one αß-heterodimer around the RC. From the cryo-EM density map, two previously unrecognized integral membrane proteins, referred to as protein G and protein Q, were identified. Both of these proteins are single transmembrane-spanning helices located between the LH1 ring and the RC L-subunit and are absent from the LH1-RC complexes of all other purple bacteria of which the structures have been determined so far. Besides bacteriochlorophyll b molecules (B1020) located on the periplasmic side of the Hlr. halochloris membrane, there are also two arrays of bacteriochlorophyll b molecules (B800 and B820) located on the cytoplasmic side. Only a single copy of a carotenoid (lycopene) was resolved in the Hlr. halochloris LH1-α3ß3 and this was positioned within the complex. The potential quinone channel should be the space between the LH1-α3ß3 that accommodates the single lycopene but does not contain a γ-polypeptide, B800 and B820. Our results provide a structural explanation for the unusual Qy red shift and carotenoid absorption in the Hlr. halochloris spectrum and reveal new insights into photosynthetic mechanisms employed by a species that thrives under the harshest conditions of any phototrophic microorganism known.

4.
Hum Mol Genet ; 30(9): 823-835, 2021 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-33517445

RESUMEN

Currently, it remains difficult to identify which single nucleotide polymorphisms (SNPs) identified by genome-wide association studies (GWAS) are functional and how various functional SNPs (fSNPs) interact and contribute to disease susceptibility. GWAS have identified a CD40 locus that is associated with rheumatoid arthritis (RA). We previously used two techniques developed in our laboratory, single nucleotide polymorphism-next-generation sequencing (SNP-seq) and flanking restriction enhanced DNA pulldown-mass spectrometry (FREP-MS), to determine that the RA risk gene RBPJ regulates CD40 expression via a fSNP at the RA-associated CD40 locus. In the present work, by applying the same approach, we report the identification of six proteins that regulate RBPJ expression via binding to two fSNPs on the RA-associated RBPJ locus. Using these findings, together with the published data, we constructed an RA-associated signal transduction and transcriptional regulation network (STTRN) that functionally connects multiple RA-associated risk genes via transcriptional regulation networks (TRNs) linked by CD40-induced nuclear factor kappa B (NF-kB) signaling. Remarkably, this STTRN provides insight into the potential mechanism of action for the histone deacetylase inhibitor givinostat, an approved therapy for systemic juvenile idiopathic arthritis. Thus, the generation of disease-associated STTRNs based on post-GWAS functional studies is demonstrated as a novel and effective approach to apply GWAS for mechanistic studies and target identification.


Asunto(s)
Artritis Reumatoide , Estudio de Asociación del Genoma Completo , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/genética , Artritis Reumatoide/metabolismo , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo/métodos , Inhibidores de Histona Desacetilasas/farmacología , Humanos , FN-kappa B/genética , FN-kappa B/metabolismo , Polimorfismo de Nucleótido Simple , Transducción de Señal/genética
5.
PLoS Genet ; 16(10): e1009068, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33057331

RESUMEN

Diphthamide is a unique post-translationally modified histidine residue (His715 in all mammals) found only in eukaryotic elongation factor-2 (eEF-2). The biosynthesis of diphthamide represents one of the most complex modifications, executed by protein factors conserved from yeast to humans. Diphthamide is not only essential for normal physiology (such as ensuring fidelity of mRNA translation), but is also exploited by bacterial ADP-ribosylating toxins (e.g., diphtheria toxin) as their molecular target in pathogenesis. Taking advantage of the observation that cells defective in diphthamide biosynthesis are resistant to ADP-ribosylating toxins, in the past four decades, seven essential genes (Dph1 to Dph7) have been identified for diphthamide biosynthesis. These technically unsaturated screens raise the question as to whether additional genes are required for diphthamide biosynthesis. In this study, we performed two independent, saturating, genome-wide CRISPR knockout screens in human cells. These screens identified all previously known Dph genes, as well as further identifying the BTB/POZ domain-containing transcription factor Miz1. We found that Miz1 is absolutely required for diphthamide biosynthesis via its role in the transcriptional regulation of Dph1 expression. Mechanistically, Miz1 binds to the Dph1 proximal promoter via an evolutionarily conserved consensus binding site to activate Dph1 transcription. Therefore, this work demonstrates that Dph1-7, along with the newly identified Miz1 transcription factor, are likely to represent the essential protein factors required for diphthamide modification on eEF2.


Asunto(s)
Quinasa del Factor 2 de Elongación/genética , Histidina/análogos & derivados , Factores de Transcripción de Tipo Kruppel/genética , Antígenos de Histocompatibilidad Menor/genética , Proteínas Supresoras de Tumor/genética , Animales , Dominio BTB-POZ/genética , Sistemas CRISPR-Cas/genética , Regulación de la Expresión Génica/genética , Histidina/biosíntesis , Histidina/genética , Humanos , Metiltransferasas , Ratones , Regiones Promotoras Genéticas/genética , Unión Proteica/genética , Procesamiento Proteico-Postraduccional/genética , Células RAW 264.7 , Factores de Transcripción/genética
6.
Nucleic Acids Res ; 48(6): 3195-3210, 2020 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-32095829

RESUMEN

Methylation of nucleotides in ribosomal RNAs (rRNAs) is a ubiquitous feature that occurs in all living organisms. The formation of methylated nucleotides is performed by a variety of RNA-methyltransferases. Chloroplasts of plant cells result from an endosymbiotic event and possess their own genome and ribosomes. However, enzymes responsible for rRNA methylation and the function of modified nucleotides in chloroplasts remain to be determined. Here, we identified an rRNA methyltransferase, CMAL (Chloroplast MraW-Like), in the Arabidopsis chloroplast and investigated its function. CMAL is the Arabidopsis ortholog of bacterial MraW/ RsmH proteins and accounts to the N4-methylation of C1352 in chloroplast 16S rRNA, indicating that CMAL orthologs and this methyl-modification nucleotide is conserved between bacteria and the endosymbiont-derived eukaryotic organelle. The knockout of CMAL in Arabidopsis impairs the chloroplast ribosome accumulation and accordingly reduced the efficiency of mRNA translation. Interestingly, the loss of CMAL leads not only to defects in chloroplast function, but also to abnormal leaf and root development and overall plant morphology. Further investigation showed that CMAL is involved in the plant development probably by modulating auxin derived signaling pathways. This study uncovered the important role of 16S rRNA methylation mediated by CMAL in chloroplast ribosome biogenesis and plant development.


Asunto(s)
Metiltransferasas/genética , Desarrollo de la Planta/genética , ARN Ribosómico 16S/genética , Ribosomas/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Cloroplastos/genética , Regulación de la Expresión Génica de las Plantas/genética , Metilación , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Plastidios/genética , ARN Mensajero/genética , ARN de Planta/genética
7.
Arch Gynecol Obstet ; 303(1): 27-36, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32989508

RESUMEN

PURPOSE: The efficacy of progesterone supplementation in the treatment of threatened miscarriage is controversial. This meta-analysis was to evaluate the correlation between progesterone and improving pregnancy outcomes in women with threatened miscarriage. METHODS: We searched PubMed, EMBASE, and the Cochrane Library for relevant randomized controlled trials (RCTs) to demonstrate the efficacy of progesterone on the threatened miscarriage pregnancy. The outcomes were miscarriage, preterm birth, and live birth. RESULTS: Nine RCTs comparing 4907 patients were included in this study. Compared with placebo or no treatment, progesterone supplementation had a relationship with a reduction in the rate of miscarriage [RR 0.70 95% Cl (0.52, 0.94)]. There was no significant difference between progesterone supplementation and placebo or no treatment in preterm birth [RR 0.87 95% Cl (0.52, 1.47) and live birth (RR 1.02 95% Cl (0.98, 1.07)]. CONCLUSION: Progesterone supplementation did not significantly improve the incidence of preterm and live birth, so progesterone treatment of threatened miscarriage may be unhelpful.


Asunto(s)
Amenaza de Aborto/tratamiento farmacológico , Progesterona/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Adulto , Femenino , Humanos , Nacimiento Vivo , Embarazo , Resultado del Embarazo , Nacimiento Prematuro/epidemiología , Progesterona/uso terapéutico
8.
Xenobiotica ; 50(5): 593-601, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31505985

RESUMEN

Lovastatin shows low bioavailability (lower than 5%) after oral administration because of the poor aqueous solubility and widely metabolized by CYP3A4.Lovastatin solid dispersion was designed to enhance the dissolution. The in vitro intestinal absorption study indicated an increase in the apparent permeability of different intestinal segments compared with crude lovastatin. In the range of 12.5-50 µg/ml, the absorption of both lovastatin and lovastatin solid dispersion were found to be a passive process in rat's jejunum and ileum, but not endocytosis process. CYP3A4 inhibitor (ketoconazole) significantly increased the intestinal absorption of lovastatin and lovastatin solid dispersion. However, P-glycoprotein efflux inhibitor (verapamil) had little effect on them.The absolute bioavailability of lovastatin and lovastatin acid after oral administration of lovastatin solid dispersion were increased by about 2.01-fold and 1.40-fold than that of lovastatin suspension. The oral bioavailability of lovastatin and lovastatin acid after oral administration of lovastatin solid dispersion with 10 mg/kg kaempferol (CYP3A4 inhibitor) were increased about 3.79-fold and 2.51-fold than that of lovastatin suspension, and the absolute bioavailability of lovastatin was up to 33.0%.As a result, co-administration of lovastatin solid dispersion with kaempferol could be a promising delivery system to improve the oral bioavailability of lovastatin.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/metabolismo , Quempferoles/metabolismo , Lovastatina/metabolismo , Administración Oral , Animales , Disponibilidad Biológica , Inhibidores de Hidroximetilglutaril-CoA Reductasas/administración & dosificación , Absorción Intestinal , Quempferoles/administración & dosificación , Lovastatina/administración & dosificación , Ratas
9.
J Dairy Sci ; 103(7): 5816-5829, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32418689

RESUMEN

Fermented milk is an effective carrier for probiotics, the consumption of which improves host health. The beneficial effects of probiotics, prebiotics, and synbiotics on gut dysbiosis have been reported previously. However, the way in which specific probiotics, prebiotics, and synbiotics regulate intestinal microbes remains unclear. Therefore, the probiotics Lactobacillus rhamnosus AS 1.2466 and Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842 and the prebiotics xylooligosaccharide and red ginseng extracts were fed to mice to determine their effects on the intestinal microbiota. Then, mice were administered xylooligosaccharide and L. rhamnosus (synthesis) by gavage, and the number of L. rhamnosus was determined in the intestine at different times. The results show that probiotics and prebiotics can quickly reduce the Firmicutes/Bacteroidetes ratio, inhibit harmful bacteria (such as Klebsiella and Escherichia coli), and accelerate the recovery of beneficial intestinal microorganisms (such as Lactobacillus). In a complex intestinal microecology, different probiotics and prebiotics have different effects on specific intestinal microorganisms that cannot be recovered in the short term. In addition, after 20 d of intragastric xylooligosaccharide addition at 0.12 g/kg of body weight, L. rhamnosus colonization in the mouse ileum was 7.48 log cfu/mL, which was higher than in the low-dose group, prolonging colonization time and increasing the number of probiotics in the intestine. Therefore, this study demonstrated that probiotics and prebiotics can promote the balance of intestinal microbiota by regulating specific microbes in the intestine, and the effects of a suitable combination of synbiotics are beneficial, laying the foundation for the development of new dairy products rich in synbiotics.


Asunto(s)
Bacterias/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Prebióticos , Probióticos/farmacología , Simbióticos , Ampicilina/farmacología , Animales , Antibacterianos/farmacología , Microbioma Gastrointestinal/fisiología , Glucuronatos/administración & dosificación , Glucuronatos/farmacología , Lactobacillus delbrueckii/química , Lacticaseibacillus rhamnosus/química , Masculino , Ratones , Ratones Endogámicos BALB C , Oligosacáridos/administración & dosificación , Oligosacáridos/farmacología , Panax/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología , Prebióticos/administración & dosificación , Probióticos/administración & dosificación , Organismos Libres de Patógenos Específicos , Simbióticos/administración & dosificación
10.
Molecules ; 25(21)2020 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-33158074

RESUMEN

Phenol red (PR) is a widely used marker for water flux correction in studies of in situ perfusion, in which intestinal absorption usually leads to the underestimation of results. In this paper, we propose a novel marker polyethylene glycol (PEG)-PR (i.e., PR modified by PEGylation) with less permeability and evaluate its application in an in situ perfusion model in rats. PEG-PR was synthesized by the chemical conjunction of polyethylene glycol-4k/5k (PEG-4k/5k) and PR. The synthesized PEG-PR was then characterized using 1H-NMR, 13C-NMR, ultraviolet (UV), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analyses. The low permeability of PEG-PR was assessed using everted gut sac (EGS) methods. The apparent permeability coefficients (Papp, 3-8 × 10-7 cm/s) of PEG4k/5k-PR exhibited a nearly 15-fold reduction compared to that of PR. The different concentrations of PEG4k/5k-PR did not contribute to the Papp value or cumulative permeable percentage (about 0.02-0.06%). Furthermore, the larger molecular weight due to PEGylation (PEG5k-PR) enhanced the nonabsorbable effect. To evaluate the potential application of the novel marker, atenolol, ketoprofen, and metoprolol, which represent various biopharmaceutics classification system (BCS) classes, were selected as model drugs for the recirculation perfusion method. The water flux corrected by PEG4k/5k-PR reflected the accuracy due to the nonabsorbable effect, while the effective intestinal membrane permeability (Peff) of atenolol corrected by PEG4k/5k-PR showed a statistically significant increase (p < 0.05) in different intestinal segments. In conclusion, PEG-PR is a promising marker for the permeability estimation when using the in situ perfusion model in rats.


Asunto(s)
Absorción Intestinal , Modelos Biológicos , Fenolsulfonftaleína , Polietilenglicoles , Agua/metabolismo , Animales , Evaluación de Medicamentos , Masculino , Perfusión , Permeabilidad , Fenolsulfonftaleína/química , Fenolsulfonftaleína/farmacocinética , Fenolsulfonftaleína/farmacología , Polietilenglicoles/química , Polietilenglicoles/farmacología , Ratas , Ratas Wistar
11.
AAPS PharmSciTech ; 21(5): 160, 2020 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-32476084

RESUMEN

The aim of this present study was to investigate the ability of different dissolution methods to predict the in vivo performance of efonidipine hydrochloride (EFH). The solid dispersions of EFH were prepared by solvent evaporation method with HPMC-AS as matrix and urea as a pH adjusting agent. The paddle method, the open-loop, and the closed-loop flow-through cell methods were studied. In the study, Weibull's model was the best fit to explain release profiles. The pharmacokinetics behaviors of two kinds of solid dispersions with different release rate were investigated in comparison to the EFH after oral administration in rats. In vivo absorption was calculated by a numerical deconvolution method. In the study, the level A in vivo and in vitro correlation (IVIVC) was utilized. The correlation coefficient was calculated and interpreted by means of linear regression analysis (Origin.Pro.8.5 software). As a result, excellent IVIVC for solid dispersions and crude drug (r2 = 0.9352-0.9916) was obtained for the dissolution rate determined with flow-through cell open-loop system in phosphate buffer solution with 0.1% (w/v) polysorbate 80 at pH 6.5, the flow-rate of 4 mL/min. In addition, the self-assembled flow cell system had good repeatability and accuracy. The dissolution rate of the solid dispersion could be slowed down by the flow-through method, and the difference caused by preparation was significantly distinguished. The study demonstrated that flow-through cell method of the open-loop, compared with paddle method, was suitable for predicting in vivo performance of EFH solid dispersions.


Asunto(s)
Bloqueadores de los Canales de Calcio/química , Dihidropiridinas/química , Nitrofenoles/química , Animales , Bloqueadores de los Canales de Calcio/farmacocinética , Dihidropiridinas/farmacocinética , Técnicas In Vitro , Masculino , Nitrofenoles/farmacocinética , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacocinética , Preparaciones Farmacéuticas , Ratas , Ratas Sprague-Dawley , Solubilidad , Solventes , Agua
12.
Pharm Res ; 37(1): 4, 2019 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-31823030

RESUMEN

PURPOSE: The discovery of nano drug delivery system has rendered a great hope for improving cancer therapy. However, there are some inevitable obstacles that constrain its development, such as the physical and biological barriers, the toxicity of carrier materials and the physiological toxicity of drugs. Here, we report a polymeric prodrug micelle (PPM) with pH/redox dual-sensitivity, which was prepared using methoxy poly (ethylene glycol) (mPEG) with favorable biosafety to improve cancer therapy. METHOD: The tumor microenvironment stimuli-responsive PPMs were prepared and characterized in vitro and in vivo. RESULTS: Our data displayed that the PPMs with excellent biocompatibility exhibited the stimuli-responsive drug release behavior under the microenvironment of cancer cells, superior cellular internalization and lower cytotoxicity. A new method to control drug release behavior was proposed by comparing the release behavior of PPMs formed by PEG of different molecular weight. Furthermore, the fabricated PPMs exhibited the "oral-like" blood concentration curve, improved biodistribution, reduced tissue toxicity and excellent antitumor efficiency in vivo. Consistently, these results indicated that PPMs improved chemotherapeutic efficiency and reduced side effects of the model drug doxorubicin (DOX). CONCLUSION: The prepared pH/redox dual-sensitive PPM enhanced the chemotherapy effect on the tumor site while reducing the physiological toxicity of DOX. Graphical Abstract.


Asunto(s)
Portadores de Fármacos/química , Micelas , Polietilenglicoles/química , Profármacos/química , Microambiente Tumoral , Células A549 , Animales , Antineoplásicos/administración & dosificación , Preparaciones de Acción Retardada , Doxorrubicina/administración & dosificación , Humanos , Masculino , Ratones Endogámicos BALB C , Profármacos/administración & dosificación , Ratas Sprague-Dawley
13.
AAPS PharmSciTech ; 20(4): 150, 2019 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-30903519

RESUMEN

In this study, borneol, a natural active compound was applied to improve the bioavailability of curcumin (CUR). In order to increase CUR solubility and dissolution, solid dispersions (SDs) were prepared with the matrix of polyvinylpyrrolidone (PVP) at various ratios by solvent evaporation method. CUR was evidenced to exist as amorphous state in solid dispersion by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Fourier-transform infrared spectroscopy (FT-IR) was utilized to confirm intermolecular hydrogen bonding. The SD at the ratio of 1:3 (CUR:PVP) exhibited the optimal solubility and dissolution rate in various media. The results of ex vivo permeability studies by everted gut sac method showed that the apparent permeability coefficients (Papp) of CUR in SD across the duodenum, jejunum, and ileum had been significantly improved by co-incubation of borneol, and the improvement degree relied on the concentration of borneol. The pharmacokinetic results in rats indicated that the AUC0-t of CUR-SD (40 mg/kg) co-administration of borneol (90 mg/kg) were 2.53-fold higher than CUR-SD alone, and 19.41-fold higher than pure CUR (200 mg/kg) with borneol (90 mg/kg). Therefore, the combination of borneol and solid dispersion strategy provide a potential approach to enhance the oral bioavailability of CUR.


Asunto(s)
Canfanos/administración & dosificación , Curcumina/farmacocinética , Administración Oral , Animales , Área Bajo la Curva , Disponibilidad Biológica , Rastreo Diferencial de Calorimetría , Curcumina/administración & dosificación , Enlace de Hidrógeno , Masculino , Difracción de Polvo , Ratas , Ratas Sprague-Dawley , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier
14.
AAPS PharmSciTech ; 20(5): 212, 2019 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-31165303

RESUMEN

Psoriasis is an autoimmune disorder disease with pink-colored plaques and excessive proliferation which is hard to be cured completely. The study focuses on the anti-psoriatic efficacy of O/O paclitaxel ointment which can promote the assembly of microtubules and lead to death of overproliferation cells of the psoriasis epidermal. A high-speed shearing method was adopted in preparing the ointment, in which propylene carbonate was used as the internal oil phase to solve paclitaxel completely. It was characterized by the appearance, particle size, rheological behavior, and in vitro release. The amount of paclitaxel retained in normal skin and psoriatic skin was 1.00 ± 0.50 versus 1.53 ± 0.48 µg/g for 0.03% PTX ointment, 1.30 ± 0.39 versus 2.77 ± 0.49 µg/g for 0.1% PTX ointment, and 2.22 ± 0.92 versus 6.65 ± 0.87 µg/g for 0.3% PTX ointment, respectively, which implied that paclitaxel could better retain in inflamed skin than in normal skin; also the amount of drug retained in the skin was proportional to drug content. Paclitaxel ointment displayed good topical tolerance after repeated application on normal mice skin. The therapeutic efficacy of paclitaxel ointment was evaluated with an imiquimod-induced psoriatic model. A significant improvement has been shown both in the phenotypic and histopathological features of psoriatic skin treated with the ointment. There was also a significant reduction in the epidermal thickness compared to the imiquimod group. The findings confirm that the O/O PTX ointment without any surfactant appears to be a promising approach for the treatment of psoriasis.


Asunto(s)
Paclitaxel/uso terapéutico , Psoriasis/tratamiento farmacológico , Administración Tópica , Animales , Humanos , Imiquimod/efectos adversos , Masculino , Ratones , Ratones Endogámicos BALB C , Pomadas , Paclitaxel/administración & dosificación , Tamaño de la Partícula , Psoriasis/inducido químicamente , Piel/efectos de los fármacos , Tensoactivos
15.
J Cell Mol Med ; 22(2): 1190-1201, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29077259

RESUMEN

Long-term peritoneal dialysis is accompanied by functional and histopathological alterations in the peritoneal membrane. In the long process of peritoneal dialysis, high-glucose peritoneal dialysis solution (HGPDS) will aggravate the peritoneal fibrosis, leading to decreased effectiveness of peritoneal dialysis and ultrafiltration failure. In this study, we found that the coincidence of elevated TGF-ß1 expression, autophagy, apoptosis and fibrosis in peritoneal membrane from patients with peritoneal dialysis. The peritoneal membranes from patients were performed with immunocytochemistry and transmission electron microscopy. Human peritoneal mesothelial cells were treated with 1.5%, 2.5% and 4.25% HGPDS for 24 hrs; Human peritoneal mesothelial cells pre-treated with TGF-ß1 (10 ng/ml) or transfected with siRNA Beclin1 were treated with 4.25% HGPDS or vehicle for 24 hrs. We further detected the production of TGF-ß1, activation of TGF-ß1/Smad2/3 signalling, induction of autophagy, EMT, fibrosis and apoptosis. We also explored whether autophagy inhibition by siRNA targeting Beclin 1 reduces EMT, fibrosis and apoptosis in human peritoneal mesothelial cells. HGPDS increased TGF-ß1 production, activated TGF-ß1/Smad2/3 signalling and induced autophagy, fibrosis and apoptosis hallmarks in human peritoneal mesothelial cells; HGPDS-induced Beclin 1-dependent autophagy in human peritoneal mesothelial cells; Autophagy inhibition by siRNA Beclin 1 reduced EMT, fibrosis and apoptosis in human peritoneal mesothelial cells. Taken all together, these studies are expected to open a new avenue in the understanding of peritoneal fibrosis, which may guide us to explore the compounds targeting autophagy and achieve the therapeutic improvement of PD.


Asunto(s)
Apoptosis , Autofagia , Diálisis Peritoneal/efectos adversos , Fibrosis Peritoneal/etiología , Fibrosis Peritoneal/patología , Peritoneo/patología , Adulto , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Beclina-1/metabolismo , Cateterismo , Soluciones para Diálisis/farmacología , Transición Epitelial-Mesenquimal/efectos de los fármacos , Epitelio/metabolismo , Epitelio/patología , Epitelio/ultraestructura , Glucosa , Humanos , Masculino , Persona de Mediana Edad , Peritoneo/efectos de los fármacos , Peritoneo/ultraestructura , Transducción de Señal/efectos de los fármacos , Proteínas Smad/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo
16.
Neurosurg Rev ; 41(4): 945-956, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28258418

RESUMEN

There is a controversy about the effects of hypertonic saline (HS) used for brain relaxation in patients requiring craniotomies. We conducted a meta-analysis to compare the efficacy of equiosmolar hypertonic saline with mannitol on intraoperative brain relaxation in patients undergoing craniotomies. We searched PubMed, EMBASE, Cochrane Library databases, and Web of Science for randomized controlled trials (RCTs). The outcome indicators included brain relaxation, hemodynamic status, fluid volume, and blood chemistry. A total of nine RCTs involving 665 patients were identified and included. There was a greater increase in the odds of good intraoperative brain relaxation in the HS group (odds ratio (OR) 2.05, 95% confidence interval (CI) 1.40~3.01; P = 0.0002) compared with mannitol. In comparison with HS, mannitol slightly reduced the central venous pressure (CVP) (mean difference (MD) 1.03, 95% CI 0.03~2.03; P = 0.04) as well as significantly increasing the diuretic effect regardless of the dosage of HS (standardized mean difference (SMD) -0.86, 95% CI -1.35~-0.37; P = 0.0006). HS increased the plasma sodium level significantly (MD 7.86, 95% CI 2.78 ~ 12.95, P = 0.002) but reduced the intraoperative fluid intake (SMD -0.56, 95% CI -0.98~-0.15, P = 0.008). However, there were no significant differences in plasma osmolality and mean arterial pressure (MAP). Our results suggest that there appears to be better brain relaxation without a significant increase in urine volume in the HS group compared with mannitol in patients requiring craniotomies. High-quality RCTs with larger sample sizes will be required in the future to confirm the conclusions.


Asunto(s)
Craneotomía/métodos , Diuréticos/uso terapéutico , Manitol/uso terapéutico , Procedimientos Neuroquirúrgicos/métodos , Solución Salina Hipertónica/uso terapéutico , Soluciones/uso terapéutico , Diuréticos/administración & dosificación , Humanos , Manitol/administración & dosificación , Ensayos Clínicos Controlados Aleatorios como Asunto , Solución Salina Hipertónica/administración & dosificación
17.
Drug Dev Ind Pharm ; 44(12): 1990-1999, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30058391

RESUMEN

The purpose of this research was to develop multiple-unit gastric floating mini-tablets and to evaluate the possibility of using these mini-tablets as a delivery system to improve the drug absorption for drugs with a narrow absorption window. Mini-tablets were prepared using hydroxypropyl methylcellulose (HPMC K100M) and carbopol 971P as release retarding agents and sodium bicarbonate (NaHCO3) as gas-forming agent. The properties of the prepared mini-tablets in terms of floating characteristic parameters and in vitro release were evaluated. Furthermore, in vivo gastric retention study in rats and in vivo pharmacokinetic study in rabbits of the optimized formulation were performed. The optimized mini-tablets containing 45% HPMC K100M, 15% stearyl alcohol, 13% carbopol 971P, and 12% NaHCO3 were found to float immediately within 1 min and duration more than 9 h. The in vivo gastric retention study results indicated that the mini-tablets could retain in the stomach for more than 6.67 h. Furthermore, the AUC0-t of the floating mini-tablets (6849.83 ± 753.80 h ng·mL-1) was significantly higher than that of marketed sustained-release tablets XATRAL®XL (4970.16 ± 924.60 h ng·mL-1). All these results illustrated that the gastric floating mini-tablets might be a promising drug delivery system for drugs with a narrow absorption window.


Asunto(s)
Composición de Medicamentos/métodos , Sistemas de Liberación de Medicamentos/métodos , Diseño de Fármacos , Liberación de Fármacos , Quinazolinas/farmacocinética , Administración Oral , Animales , Disponibilidad Biológica , Química Farmacéutica , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Excipientes/química , Mucosa Gástrica/metabolismo , Absorción Gastrointestinal , Masculino , Quinazolinas/administración & dosificación , Quinazolinas/química , Conejos , Ratas , Ratas Sprague-Dawley , Solubilidad , Espectroscopía Infrarroja Corta , Comprimidos , Factores de Tiempo
18.
AAPS PharmSciTech ; 19(7): 3277-3286, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30215168

RESUMEN

Alfuzosin hydrochloride is an appropriate candidate drug to prepare a gastro-retention controlled release dosage form since it demonstrates a narrow absorption window in the proximal section of the gastrointestinal tract with a short half-life. The purpose of the present study was to develop and optimize a gastro-floating tablet of alfuzosin hydrochloride by using the compression coating method for controlling drug release in a controlled manner. The floating tablets were developed utilizing hydroxypropyl methylcellulose and carbomer as matrix materials. The impact of formulation factors on buoyancy property and in vitro drug release of the floating tablet was investigated. The "similarity factor" (f2) was used as the indicator for the optimization of the formulations. Furthermore, in vivo pharmacokinetic study in rabbits and correlation of in vitro/in vivo study were also performed. It was found that the optimized formulation F9 could float immediately less than 2 min and remain lastingly buoyant over 24 h and follow zero-order release kinetics well. In comparison with the commercially available prolonged release tablets XATRAL® XL, the prepared floating tablet exhibited similar pharmacokinetic parameters (Cmax, Tmax, t1/2, and AUC0 - t) and plasma concentration versus time profile. Moreover, it indicated from the correlation of in vitro/in vivo study that the floating tablets exhibited a good correlation of in vitro/in vivo. In summary, the compression coating gastro-floating tablets might be a promising drug delivery system for alfuzosin hydrochloride to control drug release.


Asunto(s)
Sistemas de Liberación de Medicamentos , Quinazolinas/administración & dosificación , Resinas Acrílicas/química , Animales , Preparaciones de Acción Retardada , Liberación de Fármacos , Derivados de la Hipromelosa/química , Quinazolinas/química , Quinazolinas/farmacocinética , Conejos , Comprimidos Recubiertos
19.
Plant Cell Physiol ; 58(3): 607-621, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28138058

RESUMEN

Plant transcription factors generally act in complex regulatory networks that function at multiple levels to govern plant developmental programs. Dissection of the interconnections among different classes of transcription factors can elucidate these regulatory networks and thus improve our understanding of plant development. Here, we investigated the molecular and functional relationships of the transcription factors ABSCISIC ACID INSENSITIVE 4 (ABI4) and members of the BASIC PENTACYSTEINE (BPC) family in lateral root (LR) development of Arabidopsis thaliana. Genetic analysis showed that BPCs promote LR development by repressing ABI4 expression. Molecular analysis showed that BPCs bind to the ABI4 promoter and repress ABI4 transcription in roots. BPCs directly recruit the Polycomb Repressive Complex 2 (PRC2) to the ABI4 locus and epigenetically repress ABI4 expression by catalyzing the trimethylation of histone H3 at Lys27. In addition, BPCs and ABI4 co-ordinate their activities to fine-tune the levels of PIN-FORMED1, a component of the auxin signaling pathway, and thus modulate LR formation. These results establish a functional relationship between two universal and multiple-role transcription factors, and provide insight into the mechanisms of the transcriptional regulatory networks that affect Arabidopsis organogenesis.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Raíces de Plantas/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Metilación , Raíces de Plantas/genética , Complejo Represivo Polycomb 2 , Unión Proteica , Proteínas Represoras/genética , Factores de Transcripción/genética
20.
Helicobacter ; 22(2)2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27493095

RESUMEN

BACKGROUND: Helicobacter pylori infection is the main cause of chronic gastritis, peptic ulcer, and gastric cancer. Tip-α is a newly identified carcinogenic factor present in H. pylori. TRAF3 can activate NF-κB by both canonical and noncanonical signaling pathways. In this study, we found that the expression of TRAF3 and NF-κB was upregulated, while microRNA-3178 (miR-3178) was decreased in H. pylori-positive gastric tissues but not in H. pylori-negative tissues. MATERIALS AND METHODS: GES-1 cells were incubated with 12.5 µg/mL recombinant Tip-α (rTip-α) in RPMI1640 for 2 hours. After another 24 hours, the supernatant medium was designed as inflammatory-conditioned medium (ICM) and that from the untreated control cells was designed as untreated control medium. The release of proinflammatory cytokines from GES-1 cells and proliferation of gastric cancer cells was determined by ELISA and CCK-8 kits. Cells were transfected with the mimic, inhibitor, negative control of miR-3178, or TRAF3 siRNA control siRNA. The medium was then replaced with RPMI1640, 12.5 µg/mL rTip-α, and collected, and the total cellular RNA and protein were extracted for the following detection. RESULTS: MiR-3178 mimic prevented the increasement of TRAF3 and hence decreased activation of NF-κB signals, whereas miR-3178 inhibitor could not, in GES-1 cells with Tip-α treatment. The condition medium from miR-3178 mimic transfected GES-1 cells could inhibit proliferation and induce apoptosis of inflammation-related gastric cancer cells SGC7901 and MGC803 by decreasing the production of inflammatory cytokines TNF-α and IL-6, which were secreted by GES-1 cells. CONCLUSIONS: Taken all together, Tip-α might activate NF-κB to promote inflammation and carcinogenesis by inhibiting miR-3178 expression, which directly targeting TRAF3, during H. pylori infection in gastric mucosal epithelial cells.


Asunto(s)
Toxinas Bacterianas/metabolismo , Proliferación Celular/efectos de los fármacos , Citocinas/metabolismo , Células Epiteliales/efectos de los fármacos , Helicobacter pylori/patogenicidad , MicroARNs/metabolismo , Factor 3 Asociado a Receptor de TNF/metabolismo , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Células Epiteliales/inmunología , Células Epiteliales/fisiología , Humanos
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda