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1.
Int J Mol Sci ; 24(12)2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37373106

RESUMEN

T14 modulates calcium influx via the α-7 nicotinic acetylcholine receptor to regulate cell growth. Inappropriate triggering of this process has been implicated in Alzheimer's disease (AD) and cancer, whereas T14 blockade has proven therapeutic potential in in vitro, ex vivo and in vivo models of these pathologies. Mammalian target of rapamycin complex 1 (mTORC1) is critical for growth, however its hyperactivation is implicated in AD and cancer. T14 is a product of the longer 30mer-T30. Recent work shows that T30 drives neurite growth in the human SH-SY5Y cell line via the mTOR pathway. Here, we demonstrate that T30 induces an increase in mTORC1 in PC12 cells, and ex vivo rat brain slices containing substantia nigra, but not mTORC2. The increase in mTORC1 by T30 in PC12 cells is attenuated by its blocker, NBP14. Moreover, in post-mortem human midbrain, T14 levels correlate significantly with mTORC1. Silencing mTORC1 reverses the effects of T30 on PC12 cells measured via AChE release in undifferentiated PC12 cells, whilst silencing mTORC2 does not. This suggests that T14 acts selectively via mTORC1. T14 blockade offers a preferable alternative to currently available blockers of mTOR as it would enable selective blockade of mTORC1, thereby reducing side effects associated with generalised mTOR blockade.


Asunto(s)
Enfermedad de Alzheimer , Neuroblastoma , Ratas , Animales , Humanos , Sirolimus/farmacología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Péptidos , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Enfermedad de Alzheimer/patología , Mamíferos/metabolismo
2.
Biochem Biophys Res Commun ; 522(3): 568-573, 2020 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-31785817

RESUMEN

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a 3.0 kb polyadenylated RNA (T3.0) in the opposite strand of the open reading frame 50 (RTA) gene. The T3.0 was mis-annotated as a noncoding RNA but found to be associated with ribosomes and carries at least four translatable sORFs. Two of them, namely vSP-1 and vSP-2, have been characterized. vSP-1 enhances RTA expression by blocking RTA self-ubiquitylation and proteasome-associated degradation. T3.0 RNA is a polycistronic RNA. Furthermore, polycistronic translation has been observed in most of the cases of small peptides (microPeptides) translated from previously annotated noncoding RNAs in eukaryotes. In an effort to elucidate the mechanism underlying polycistronic sORF translation in eukaryotic cells, we found that T3.0 RNA translates vSP-1 and vSP-2 through a leaky scanning mechanism.


Asunto(s)
Regulación Viral de la Expresión Génica , Infecciones por Herpesviridae/virología , Herpesvirus Humano 8/genética , Péptidos/genética , ARN Mensajero/genética , ARN Viral/genética , Células HEK293 , Humanos , Sistemas de Lectura Abierta , Biosíntesis de Proteínas , Proteínas Virales/genética
3.
J Basic Microbiol ; 54(12): 1342-9, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24912946

RESUMEN

Two aerobic bacterial consortia namely Con T and Con R were developed by enrichment technique from termite gut and cow dung respectively, using xylan as a sole carbon source. Molecular characterization of Con R based on 16S rRNA sequence analysis showed the presence of Pannonibacter sp. R-3 and Pseudoxanthomas sp. R-5. On the other hand, Con T showed the presence of Pseudoxanthomas sp. T-5, Cellulosimicrobium sp. T-21, and Gordonia sp. T-30. Being the maximum xylanase producer among the five isolates and being a novel xylanase producing bacterial genus, Gordonia sp. T-30 was selected. Xylanase produced by Gordonia sp. T-30 showed optimum activity at 60 °C and pH 9. Xylanase was 95% stable for 120 min at pH 9.0 and 98% stable at 60 °C for 90 min. Xylanase activity was stimulated in the presence of organic solvents such as petroleum ether, acetone, diethyl ether, n-hexane, and benzene. Detergent like cetyltrimethylammonium bromide and presence of NaCl also accelerated the xylanase function. Comparative evaluation was studied between sterilized and non-sterilized solid fermentation to produce xylanase by Gordonia sp. T-30 using various agricultural residues as growth substrate in cost effective manner. Industrially important features endowed by this xylanase make it a very promising candidate for food, feed, and fuel industry.


Asunto(s)
Endo-1,4-beta Xilanasas/química , Bacteria Gordonia/enzimología , Cloruro de Sodio/química , Solventes/química , Tensoactivos/química , Animales , Bovinos/microbiología , Estabilidad de Enzimas , Heces/microbiología , Fermentación , Genes de ARNr , Bacteria Gordonia/aislamiento & purificación , Intestinos/microbiología , Isópteros/microbiología , Consorcios Microbianos
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 285: 121874, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36122466

RESUMEN

We designed the TPA-based linear pyrazine derivatives of PP-1 and PP-2, synthesized using the conventional Suzuki cross-linking reaction. It was followed by photophysical studies such as aprotic solvent (Haxene to DMF). A red-shift was observed from the non-polar aprotic solvent to the polar aprotic solvent, and the emission intensity was gradually decreased. In addition, the Aggregation-induced emission (AIE) effect has been studied against the DMF/water addition of linear pyrazine compounds. It showed a classic aggregation-caused quenching effect (ACQ) and red-shifted at an increase of (fw) 0 to 40%. After this case, when the water fraction in these studies was increased by (fw) 50 to 90%, a blue shift and a mild AIE effect has occurred. And also, was investigated acidochromic effect of compounds PP-1 and PP-2 using TFA acid. Absorption and emission intensity were gradually reduced as the acid concentration increased for these studies, while the new peaks appeared red-shifted in the absorption spectrum. They were examined before and after exposure to UV light irradiation in the synthesized dye compounds.


Asunto(s)
Pirazinas , Agua , Espectrometría de Fluorescencia , Solventes , Fenómenos Químicos
5.
Front Microbiol ; 12: 689929, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34276622

RESUMEN

BisI is a sequence-specific and 5-methylcytosine (m5C)-dependent restriction endonuclease (REase), that cleaves the modified DNA sequence Gm5CNGC (G indicates that the cytosine opposite to G is modified). We expressed and purified a number of BisI homologs from sequenced bacterial genomes and used Illumina sequencing to determine the Pam7902I (Esp638I-like) cleavage sites in phage Xp12 DNA. One BisI homolog KpnW2I is EcoBLMcrX-like, cleaving GCNGC/RCNGY/RCNRC sites with m5C. We also cloned and expressed three BisI homologs from metagenome sequences derived from thermophilic sources. One enzyme EsaTMI is active at 37 to 65°C. EsaHLI cleaves GCNGC sites with three to four m5C and is active up to 50°C. In addition, we determined the number and position of m5C in BisI sites for efficient cleavage. BisI cleavage efficiency of GCNGC site is as following: Gm5CNGC (two internal m5C) > Gm5CNGC (one internal m5C) > GCNGm5C (one external m5C) > > GCNGC (unmodified). Three or four m5C in GCNGC site also supports BisI cleavage although partial inhibition was observed on duplex oligos with four m5C. BisI can be used to partially cleave a desired GCNGC site targeted with a complementary oligonucleotide (hemi-methylated). The m5C-dependent BisI variants will be useful for epigenetic research.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117411, 2020 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-31362187

RESUMEN

The present study delves into the interaction of a potent cancer-cell photosensitizer Norharmane (NHM) with non-ionic triblock copolymer P123, followed by the assessment of the stability of the formed complex in the presence of ß-cyclodextrin (ß-CD). Spectroscopic results unveil the modulation of the prototropic equilibrium of NHM within the constrained microheterogeneous medium of the copolymer micelle to be favoured towards the neutral species of NHM over the cationic counterpart; which has been aptly rationalized invoking the key role of hydrophobic interaction in the association process and is further reinforced from steady-state and time-resolved spectroscopic measurements. The micropolarity of the probe-binding site has been evaluated by the archetypal ET(30) analysis revealing that the cationic probe remains in the corona region of the micelle instead of penetrating deeper into the micellar core. Moreover, the effect of ß-CD on the stability of the NHM-bound P123 aggregates has also been investigated, revealing that ß-CD can be used as a potential host for the release of the micelle-encapsulated drug through an inclusion complex formation with the P123 monomers. The result is expected to be of potential interest from medical perspective owing to the context of efficient drug release at their potential sites.


Asunto(s)
Antineoplásicos , Micelas , Fármacos Fotosensibilizantes , beta-Ciclodextrinas/química , Antineoplásicos/análisis , Antineoplásicos/química , Antineoplásicos/farmacocinética , Liberación de Fármacos , Modelos Moleculares , Fármacos Fotosensibilizantes/análisis , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacocinética , Espectrometría de Fluorescencia
7.
Nutrients ; 10(7)2018 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-30002304

RESUMEN

This study investigated the effect of high-intensity interval (HIIE) and moderate-intensity continuous exercise (MICE) on glucagon-like peptide 1 (GLP-1), appetite and energy intake (EI) in obese men. In a randomized crossover trial, 12 participants (28.4 ± 2.6 years, 35.5 ± 4.5 kg/m², 39.8 ± 2.2% body fat) performed: (I) Control (CON, no exercise); (II) MICE (20 min, 70% of maximal heart rate) and (III) HIIE (10 × 1 min at 90% of maximal heart rate with 1 min recovery). GLP-1 and appetite were assessed at: (I) PRE: pre-exercise; (II) POST: immediately post-exercise; (III) POST-1 h: 1 h post-exercise. EI was assessed after an ad libitum meal offered 1 h post-exercise and over 24 h. There was a significant time × condition interaction for GLP-1 (p = 0.035). Higher GLP-1 levels in MICE vs. CON (p = 0.024) and a trend for HIIE vs. CON (p = 0.069) POST-1h was found. Hunger was reduced immediately post-HIIE compared to CON (p < 0.01), but was not sustained POST-1 h (p > 0.05). EI did not differ between the sessions 1 h post-exercise or over 24H (p > 0.05). In summary, although MICE increased GLP-1 levels POST-1h and HIIE induced a transient reduction in hunger, both exercise protocols did not impact EI in obese men.


Asunto(s)
Regulación del Apetito , Ingestión de Alimentos , Ingestión de Energía , Terapia por Ejercicio/métodos , Péptido 1 Similar al Glucagón/sangre , Entrenamiento de Intervalos de Alta Intensidad , Obesidad/terapia , Adulto , Biomarcadores/sangre , Brasil , Estudios Cruzados , Humanos , Hambre , Masculino , Obesidad/sangre , Obesidad/fisiopatología , Obesidad/psicología , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
8.
J Colloid Interface Sci ; 498: 343-350, 2017 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-28343132

RESUMEN

The empirical polarity parameter ET(30) was determined for polyethylene terephthalate (PET) fiber and five phosphorus flame retardants by UV-Vis absorption spectrum of solvatochromic probe. To investigate the interaction between flame retardant and PET fiber during the finishing process, the partition coefficients K of these flame retardants between water and PET fiber were determined and an interesting linear relationship between lnK and ET(30) of the flame retardants was obtained, suggesting ET(30) is definitely an excellent estimation of the interaction of flame retardants with PET. Additionally, the thermodynamic criterion of this finishing process, standard Gibbs free energy of transfer of the flame retardants from water to PET fiber, ΔGt0(FR,H2O→PET), was found to linearly correlate with ET(30) of the flame retardants as well, ΔGt0(FR,H2O→PET)=0.3664∗ET(30)(FR) -18.60 (R2=0.9168), demonstrating polarity of flame retardant is an important and determining factor for its fixation on PET fiber. This work may provide theoretical guidance for choosing flame retardant finishing agent more compatible with PET fabric.

9.
Chem Phys Lipids ; 184: 52-60, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25454361

RESUMEN

Afri et al. (2014a,b) have recently reported their mapping of DMPC liposomes using (13)C NMR in conjunction with a wide range of difunctional intercalants: n-ketoesters, n-ketoacids and n-ketophosphatidylcholines. The present study initiates a comparable study of bioliposomes and erythrocyte ghosts. This required the (13)C NMR characterization of these systems for the first time, and further involved a determination of the signals of three doubly (13)C-labeled intercalants, in particular, n-ketophosphatidylcholines where n=4, 8 and 12. This study reveals that DMPC liposomes, bioliposomes and erythrocyte ghosts, with all their structural differences, are not radically different from the perspective of polarity gradient. Any differences observed reflect the additives often naturally present in these lipid systems.


Asunto(s)
Membrana Eritrocítica/química , Membrana Dobles de Lípidos/química , Liposomas/química , Espectroscopía de Resonancia Magnética , Cumarinas/química , Dimiristoilfosfatidilcolina/química , Sustancias Intercalantes/química , Microscopía Fluorescente , Termodinámica
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