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1.
J Org Chem ; 83(17): 10060-10069, 2018 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-30106576

RESUMEN

An organocatalytic [4 + 1] cyclization of o-QMs with MBH carbonates has been established using naphthylindole-derived phosphine (NIP) as an organocatalyst. By using this approach, a series of 2,3-dihydrobenzofuran derivatives have been synthesized in high yields and excellent diastereoselectivities (up to 99% yield, >95:5 dr). This reaction not only has established the first [4 + 1] cyclization of o-QMs with MBH carbonates but also represents the first application of naphthylindole-derived phosphines as organocatalysts in catalytic reactions. In addition, this reaction has also provided a useful method for constructing 2,3-dihydrobenzofuran scaffolds.

2.
Cell Metab ; 2(4): 217-25, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16213224

RESUMEN

The liver and intestine play crucial roles in maintaining bile acid homeostasis. Here, we demonstrate that fibroblast growth factor 15 (FGF15) signals from intestine to liver to repress the gene encoding cholesterol 7alpha-hydroxylase (CYP7A1), which catalyzes the first and rate-limiting step in the classical bile acid synthetic pathway. FGF15 expression is stimulated in the small intestine by the nuclear bile acid receptor FXR and represses Cyp7a1 in liver through a mechanism that involves FGF receptor 4 (FGFR4) and the orphan nuclear receptor SHP. Mice lacking FGF15 have increased hepatic CYP7A1 mRNA and protein levels and corresponding increases in CYP7A1 enzyme activity and fecal bile acid excretion. These studies define FGF15 and FGFR4 as components of a gut-liver signaling pathway that synergizes with SHP to regulate bile acid synthesis.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Circulación Enterohepática/fisiología , Factores de Crecimiento de Fibroblastos/metabolismo , Homeostasis , Transducción de Señal , Animales , Células CACO-2 , Colesterol 7-alfa-Hidroxilasa/biosíntesis , Clonación Molecular , Proteínas de Unión al ADN/metabolismo , Circulación Enterohepática/efectos de los fármacos , Epitelio/metabolismo , Factores de Crecimiento de Fibroblastos/deficiencia , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/farmacología , Perfilación de la Expresión Génica , Homeostasis/efectos de los fármacos , Humanos , Mucosa Intestinal/metabolismo , Intestinos/citología , Hígado/enzimología , Masculino , Ratones , Datos de Secuencia Molecular , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor Tipo 4 de Factor de Crecimiento de Fibroblastos/metabolismo , Receptores Citoplasmáticos y Nucleares/deficiencia , Receptores Citoplasmáticos y Nucleares/metabolismo , Transducción de Señal/efectos de los fármacos , Factores de Transcripción/metabolismo
3.
Skelet Muscle ; 8(1): 35, 2018 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-30424786

RESUMEN

BACKGROUND: In muscular dystrophy and old age, skeletal muscle repair is compromised leading to fibrosis and fatty tissue accumulation. Therefore, therapies that protect skeletal muscle or enhance repair would be valuable medical treatments. Hypoxia-inducible factors (HIFs) regulate gene transcription under conditions of low oxygen, and HIF target genes EPO and VEGF have been associated with muscle protection and repair. We tested the importance of HIF activation following skeletal muscle injury, in both a murine model and human volunteers, using prolyl hydroxylase inhibitors that stabilize and activate HIF. METHODS: Using a mouse eccentric limb injury model, we characterized the protective effects of prolyl hydroxylase inhibitor, GSK1120360A. We then extended these studies to examine the impact of EPO modulation and infiltrating immune cell populations on muscle protection. Finally, we extended this study with an experimental medicine approach using eccentric arm exercise in untrained volunteers to measure the muscle-protective effects of a clinical prolyl hydroxylase inhibitor, daprodustat. RESULTS: GSK1120360A dramatically prevented functional deficits and histological damage, while accelerating recovery after eccentric limb injury in mice. Surprisingly, this effect was independent of EPO, but required myeloid HIF1α-mediated iNOS activity. Treatment of healthy human volunteers with high-dose daprodustat reduced accumulation of circulating damage markers following eccentric arm exercise, although we did not observe any diminution of functional deficits with compound treatment. CONCLUSION: The results of these experiments highlight a novel skeletal muscle protective effect of prolyl hydroxylase inhibition via HIF-mediated expression of iNOS in macrophages. Partial recapitulation of these findings in healthy volunteers suggests elements of consistent pharmacology compared to responses in mice although there are clear differences between these two systems.


Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Glicina/análogos & derivados , Prolina Dioxigenasas del Factor Inducible por Hipoxia/antagonistas & inhibidores , Contracción Muscular , Músculo Esquelético/efectos de los fármacos , Mialgia/tratamiento farmacológico , Quinolonas/uso terapéutico , Adolescente , Adulto , Animales , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Glicina/farmacología , Glicina/uso terapéutico , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/lesiones , Músculo Esquelético/metabolismo , Mialgia/etiología , Quinolonas/farmacología
4.
Skelet Muscle ; 8(1): 38, 2018 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-30526662

RESUMEN

Following publication of the original article [1], the authors flagged that there is a discrepancy with the Availability of data and materials statement on page 12 of the article.

5.
J Clin Invest ; 112(11): 1678-87, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14623915

RESUMEN

Farnesoid X receptor (FXR) is a bile acid-activated transcription factor that is a member of the nuclear hormone receptor superfamily. Fxr-null mice exhibit a phenotype similar to Byler disease, an inherited cholestatic liver disorder. In the liver, activation of FXR induces transcription of transporter genes involved in promoting bile acid clearance and represses genes involved in bile acid biosynthesis. We investigated whether the synthetic FXR agonist GW4064 could protect against cholestatic liver damage in rat models of extrahepatic and intrahepatic cholestasis. In the bile duct-ligation and alpha-naphthylisothiocyanate models of cholestasis, GW4064 treatment resulted in significant reductions in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase, as well as other markers of liver damage. Rats that received GW4064 treatment also had decreased incidence and extent of necrosis, decreased inflammatory cell infiltration, and decreased bile duct proliferation. Analysis of gene expression in livers from GW4064-treated cholestatic rats revealed decreased expression of bile acid biosynthetic genes and increased expression of genes involved in bile acid transport, including the phospholipid flippase MDR2. The hepatoprotection seen in these animal models by the synthetic FXR agonist suggests FXR agonists may be useful in the treatment of cholestatic liver disease.


Asunto(s)
Colestasis/tratamiento farmacológico , Citoprotección , Proteínas de Unión al ADN/fisiología , Isoxazoles/farmacología , Proteínas de Transporte de Membrana , Factores de Transcripción/fisiología , Subfamilia B de Transportador de Casetes de Unión a ATP/fisiología , Transportadoras de Casetes de Unión a ATP/fisiología , Animales , Proteínas Portadoras/genética , Colestasis/metabolismo , Colestasis/patología , Proteínas de Unión al ADN/agonistas , Isocianatos/farmacología , Masculino , Naftalenos/farmacología , Transportadores de Anión Orgánico Sodio-Dependiente , Transportadores de Anión Orgánico Sodio-Independiente/genética , Ratas , Ratas Sprague-Dawley , Receptores Citoplasmáticos y Nucleares , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Receptores del Factor de Necrosis Tumoral/fisiología , Esteroide 12-alfa-Hidroxilasa/genética , Simportadores , Taurina/farmacología , Factores de Transcripción/agonistas , Ácido Ursodesoxicólico/farmacología
6.
Aging Cell ; 15(3): 582-4, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27139744

RESUMEN

Recent high-profile studies report GDF11 to be a key circulating 'anti-aging' factor. However, a screen of extracellular proteins attempting to identify factors with 'anti-aging' phenotypes in aged murine skeletal muscle satellite cells did not identify GDF11 activity. We have been unable to confirm the reported activity of GDF11, similar to other laboratories offering conflicting data and describe our attempts to do so in this short take.


Asunto(s)
Senescencia Celular/efectos de los fármacos , Factores de Diferenciación de Crecimiento/farmacología , Células Satélite del Músculo Esquelético/citología , Animales , Recuento de Células , Células HEK293 , Humanos , Ratones , Proteínas Recombinantes/farmacología , Células Satélite del Músculo Esquelético/efectos de los fármacos , Células Satélite del Músculo Esquelético/metabolismo
7.
PLoS One ; 10(8): e0134927, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26287487

RESUMEN

Nicotinamide adenine dinucleotide (NAD+) is a key cofactor required for essential metabolic oxidation-reduction reactions. It also regulates various cellular activities, including gene expression, signaling, DNA repair and calcium homeostasis. Intracellular NAD+ levels are tightly regulated and often respond rapidly to nutritional and environmental changes. Numerous studies indicate that elevating NAD+ may be therapeutically beneficial in the context of numerous diseases. However, the role of NAD+ on skeletal muscle exercise performance is poorly understood. CD38, a multi-functional membrane receptor and enzyme, consumes NAD+ to generate products such as cyclic-ADP-ribose. CD38 knockout mice show elevated tissue and blood NAD+ level. Chronic feeding of high-fat, high-sucrose diet to wild type mice leads to exercise intolerance and reduced metabolic flexibility. Loss of CD38 by genetic mutation protects mice from diet-induced metabolic deficit. These animal model results suggest that elevation of tissue NAD+ through genetic ablation of CD38 can profoundly alter energy homeostasis in animals that are maintained on a calorically-excessive Western diet.


Asunto(s)
ADP-Ribosil Ciclasa 1/genética , ADP-Ribosil Ciclasa 1/metabolismo , Dieta Occidental/efectos adversos , Enfermedades Metabólicas/genética , Enfermedades Metabólicas/metabolismo , Condicionamiento Físico Animal/fisiología , ADP-Ribosil Ciclasa/metabolismo , Animales , ADP-Ribosa Cíclica/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Músculo Esquelético/metabolismo , NAD/metabolismo , Oxidación-Reducción
8.
PLoS One ; 9(2): e90398, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24587351

RESUMEN

Satellite cells are the chief contributor to skeletal muscle growth and regeneration. The study of mouse satellite cells has accelerated in recent years due to technical advancements in the isolation of these cells. The study of human satellite cells has lagged and thus little is known about how the biology of mouse and human satellite cells compare. We developed a flow cytometry-based method to prospectively isolate human skeletal muscle progenitors from the satellite cell pool using positive and negative selection markers. Results show that this pool is enriched in PAX7 expressing cells that possess robust myogenic potential including the ability to give rise to de novo muscle in vivo. We compared mouse and human satellite cells in culture and identify differences in the elaboration of the myogenic genetic program and in the sensitivity of the cells to cytokine stimulation. These results indicate that not all mechanisms regulating mouse satellite cell activation are conserved in human satellite cells and that such differences may impact the clinical translation of therapeutics validated in mouse models. Thus, the findings of this study are relevant to developing therapies to combat muscle disease.


Asunto(s)
Desarrollo de Músculos/genética , Músculo Esquelético/metabolismo , Células Satélite del Músculo Esquelético/metabolismo , Adolescente , Adulto , Animales , Biomarcadores/metabolismo , Femenino , Citometría de Flujo , Expresión Génica , Humanos , Masculino , Ratones , Persona de Mediana Edad , Músculo Esquelético/citología , Músculo Esquelético/crecimiento & desarrollo , Proteína MioD/genética , Proteína MioD/metabolismo , Factor 5 Regulador Miogénico/genética , Factor 5 Regulador Miogénico/metabolismo , Factor de Transcripción PAX7/genética , Factor de Transcripción PAX7/metabolismo , Células Satélite del Músculo Esquelético/citología , Especificidad de la Especie
9.
J Biol Chem ; 280(36): 31792-800, 2005 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-16012168

RESUMEN

Alpha-crystallins comprise 35% of soluble proteins in the ocular lens and possess chaperone-like functions. Furthermore, the alphaA subunit (alphaA-crystallin) of alpha crystallin is thought to be "lens-specific" as only very low levels of expression were detected in a few non-lenticular tissues. Here we report that human alphaA-crystallin is expressed in human livers and is regulated by farnesoid X-activated receptor (FXR) in response to FXR agonists. AlphaA-crystallin was identified in a microarray screen as one of the most highly induced genes after treatment of HepG2 cells with the synthetic FXR ligand GW4064. Northern blot and quantitative real-time PCR analyses confirmed that alphaA-crystallin expression was induced in HepG2-derived cell lines and human primary hepatocytes and hepatic stellate cells in response to either natural or synthetic FXR ligands. Transient transfection studies and electrophoretic mobility shift assays revealed a functional FXR response element located in intron 1 of the human alphaA-crystallin gene. Importantly, immunohistochemical staining of human liver sections showed increased alphaA-crystallin expression in cholangiocytes and hepatocytes. As a member of the small heat shock protein family possessing chaperone-like activity, alphaA-crystallin may be involved in protection of hepatocytes from the toxic effects of high concentrations of bile acids, as would occur in disease states such as cholestasis.


Asunto(s)
Proteínas de Unión al ADN/fisiología , Regulación de la Expresión Génica/fisiología , Hígado/metabolismo , Factores de Transcripción/fisiología , alfa-Cristalinas/genética , Ácidos y Sales Biliares/fisiología , Línea Celular , Proteínas de Unión al ADN/agonistas , Elementos de Facilitación Genéticos , Hepatocitos/metabolismo , Humanos , Inmunohistoquímica , Intrones/fisiología , Ligandos , Receptores Citoplasmáticos y Nucleares , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción/agonistas , Transcripción Genética , Transfección , alfa-Cristalinas/biosíntesis
10.
J Clin Microbiol ; 40(8): 2860-5, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12149343

RESUMEN

A multiplex PCR method was developed to identify simultaneously multiple fungal pathogens in a single reaction. Five sets of species-specific primers were designed from the internal transcribed spacer (ITS) regions, ITS1 and ITS2, of the rRNA gene to identify Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, and Aspergillus fumigatus. Another set of previously published ITS primers, CN4 and CN5, were used to identify Cryptococcus neoformans. Three sets of primers were used in one multiplex PCR to identify three different species. Six different species of pathogenic fungi can be identified with two multiplex PCRs. Furthermore, instead of using templates of purified genomic DNA, we performed the PCR directly from yeast colonies or cultures, which simplified the procedure and precluded contamination during the extraction of DNA. A total of 242 fungal isolates were tested, representing 13 species of yeasts, four species of Aspergillus, and three zygomycetes. The multiplex PCR was tested on isolated DNA or fungal colonies, and both provided 100% sensitivity and specificity. However, DNA from only about half the molds could be amplified directly from mycelial fragments, while DNA from every yeast colony was amplified. This multiplex PCR method provides a rapid, simple, and reliable alternative to conventional methods to identify common clinical fungal isolates.


Asunto(s)
Hongos Mitospóricos/clasificación , Micosis/microbiología , Reacción en Cadena de la Polimerasa/métodos , Medios de Cultivo , Cartilla de ADN , ADN de Hongos/análisis , Humanos , Hongos Mitospóricos/genética , Técnicas de Tipificación Micológica , Sensibilidad y Especificidad , Especificidad de la Especie , Factores de Tiempo
11.
Microbiology (Reading) ; 148(Pt 1): 203-212, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11782512

RESUMEN

Cryptococcus neoformans is a major pathogen of humans throughout the world. Using commercial mAbs to capsular epitopes, strains of C. neoformans manifest five distinct serotypes--A, B, C, D and AD. Previous studies demonstrated significant divergence among serotypes A, B, C and D, which are thought to be haploid. In this study the origins and evolution of strains of serotype AD were investigated. A portion (537 bp) of the laccase gene was cloned and sequenced from 14 strains of serotype AD. Each strain contained two different alleles and sequences for both alleles were obtained. These sequences were compared to those from serotypes A, B, C and D. This analysis indicated that each of the 14 serotype AD strains contained two phylogenetically distinct haplotypes: one haplotype was highly similar to the serotype A group and the other to the serotype D group. To explain the origins of these serotype AD strains, genealogical analysis is consistent with at least three recent and independent hybridization events. The results demonstrate that the evolution of C. neoformans is continuing and dynamic.


Asunto(s)
Cruzamientos Genéticos , Cryptococcus neoformans/clasificación , Cryptococcus neoformans/genética , Evolución Molecular , Oxidorreductasas/genética , Secuencia de Bases , Clonación Molecular , Cryptococcus neoformans/crecimiento & desarrollo , Variación Genética , Humanos , Lacasa , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN , Serotipificación
12.
Genes Dev ; 17(13): 1581-91, 2003 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-12815072

RESUMEN

The nuclear bile acid receptor FXR has been proposed to play a central role in the feedback repression of the gene encoding cholesterol 7 alpha-hydroxylase (CYP7A1), the first and rate-limiting step in the biosynthesis of bile acids. We demonstrate that FXR directly regulates expression of fibroblast growth factor-19 (FGF-19), a secreted growth factor that signals through the FGFR4 cell-surface receptor tyrosine kinase. In turn, FGF-19 strongly suppresses expression of CYP7A1 in primary cultures of human hepatocytes and mouse liver through a c-Jun N-terminal kinase (JNK)-dependent pathway. This signaling cascade defines a novel mechanism for feedback repression of bile acid biosynthesis and underscores the vital role of FXR in the regulation of multiple pathways of cholesterol catabolism in the liver.


Asunto(s)
Ácidos y Sales Biliares/biosíntesis , Colesterol 7-alfa-Hidroxilasa/genética , Proteínas de Unión al ADN/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Hepatocitos/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Animales , Antracenos/farmacología , Línea Celular , Células Cultivadas , Ácido Quenodesoxicólico/farmacología , Colesterol 7-alfa-Hidroxilasa/metabolismo , Proteínas de Unión al ADN/agonistas , Proteínas de Unión al ADN/genética , Represión Enzimática , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/farmacología , Regulación de la Expresión Génica , Humanos , Isoxazoles/farmacología , Proteínas Quinasas JNK Activadas por Mitógenos , Ratones , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-jun/metabolismo , Receptores Citoplasmáticos y Nucleares , Proteínas Recombinantes/farmacología , Elementos de Respuesta , Factores de Transcripción/agonistas , Factores de Transcripción/genética , Transfección
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