Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
J Agric Food Chem ; 69(42): 12494-12504, 2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34664500

RESUMEN

Zanthoxylum ailanthoides is a traditional spice crop in Taiwan with unique smells and tastes that differ between prickly (young) and nonprickly (mature) leaves. Different volatile terpenes between prickly young and nonprickly mature leaves were identified and considered to be one of the sources of their aromas. A transcriptome database was established to explore the biosynthesis of these compounds, and candidate terpene synthase genes were identified. The functions of these synthases were investigated using recombinant protein reactions in both purification and coexpression assays. ZaTPS1, ZaTPS2, and ZaTPS3 are germacrene D synthases, with different amino acid sequences. The main products of ZaTPS4 are trans-α-bergamotene and (E)-ß-farnesene, whereas ZaTPS5 forms multiple products, and ZaTPS6 produces ß-caryophyllene. ZaTPS7 forms monoterpene (E)-ß-ocimene and sesquiterpene (E,E)-α-farnesene. Reverse transcription PCR of ZaTPS gene expression in young and mature leaves revealed that ZaTPS1 was responsible for the mellow aroma in mature leaves. The expression of ZaTPS6 suggested that it plays a role in the background aromas of both types of leaves. Our findings deepened the understanding of the volatile compounds of Z. ailanthoides and revealed the source of its unique aromas by clarifying the biosynthesis of these compounds.


Asunto(s)
Transferasas Alquil y Aril , Sesquiterpenos , Compuestos Orgánicos Volátiles , Zanthoxylum , Transferasas Alquil y Aril/genética , Folclore , Odorantes , Proteínas de Plantas/genética , Taiwán , Terpenos/análisis
2.
Int J Mol Sci ; 22(4)2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33670336

RESUMEN

Misfolding of prion protein (PrP) into amyloid aggregates is the central feature of prion diseases. PrP has an amyloidogenic C-terminal domain with three α-helices and a flexible tail in the N-terminal domain in which multiple octapeptide repeats are present in most mammals. The role of the octapeptides in prion diseases has previously been underestimated because the octapeptides are not located in the amyloidogenic domain. Correlation between the number of octapeptide repeats and age of onset suggests the critical role of octapeptide repeats in prion diseases. In this study, we have investigated four PrP variants without any octapeptides and with 1, 5 and 8 octapeptide repeats. From the comparison of the protein structure and the thermal stability of these proteins, as well as the characterization of amyloids converted from these PrP variants, we found that octapeptide repeats affect both folding and misfolding of PrP creating amyloid fibrils with distinct structures. Deletion of octapeptides forms fewer twisted fibrils and weakens the cytotoxicity. Insertion of octapeptides enhances the formation of typical silk-like fibrils but it does not increase the cytotoxicity. There might be some threshold effect and increasing the number of peptides beyond a certain limit has no further effect on the cell viability, though the reasons are unclear at this stage. Overall, the results of this study elucidate the molecular mechanism of octapeptides at the onset of prion diseases.


Asunto(s)
Oligopéptidos , Proteínas Priónicas , Agregado de Proteínas/efectos de los fármacos , Pliegue de Proteína/efectos de los fármacos , Animales , Línea Celular , Ratones , Oligopéptidos/química , Oligopéptidos/farmacología , Enfermedades por Prión/tratamiento farmacológico , Enfermedades por Prión/metabolismo , Enfermedades por Prión/patología , Proteínas Priónicas/química , Proteínas Priónicas/metabolismo , Dominios Proteicos , Secuencias Repetitivas de Aminoácido
3.
Plant Sci ; 304: 110790, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33568294

RESUMEN

Chamaecyparis formosensis Matsum. is an endemic and precious coniferous species of Taiwan, and is known for a high abundance of specialized metabolites, which contributes to the excellent timber durability. Several terpenoids were identified and isolated from C. formosensis wood and needles, and exhibit anti-fungal and anti-bacterial bioactivities, which may participate in plant defense against pathogens. In various identified compounds, not only cadinene and ferruginol, were identified in C. formosensis extracts but also unique diterpenoids, which include pisferal, totarol, and derivates of isoabienol. To understand the biosynthesis of these specific diterpenoids, we conducted a series of functional characterization of the C. formosensis diterpene synthases (CfdiTPSs), which participate in skeleton formation and differentiation of diterpenes. In this study, we identified eight diTPSs from C. formosensis transcriptome, and they all contain either class I or class II motif, which indicates they are all monofunctional enzymes. These candidates consist of three class II diTPSs and five class I diTPSs, and after conducting in vivo and in vitro assays, class II diTPS CfCPS1 was characterized as a (+)-copalyl diphosphate synthase ((+)-CPS), and class I diTPSs CfKSL1 could further convert (+)-copalyl diphosphate ((+)-CPP) to levopimaradiene. Meanwhile, CfKSL1 also accepted labda-13-en-8-ol diphosphate (LPP) as substrate and formed monoyl oxide. Another class I diTPS, CfKSL4, exhibits a strong enzymatic ability of isoabienol synthase, which is firstly reported in conifer. This finding provides potential participants in the biosynthesis of unique diterpenoids, and with this knowledge, we can further expand our understanding of diterpenoid metabolism in Cupressaceae and their potential role in plant defense.


Asunto(s)
Transferasas Alquil y Aril/metabolismo , Chamaecyparis/enzimología , Diterpenos/metabolismo , Proteínas de Plantas/metabolismo , Chamaecyparis/metabolismo , Clonación Molecular , Escherichia coli , Perfilación de la Expresión Génica , Espectroscopía de Resonancia Magnética , Redes y Vías Metabólicas , Organismos Modificados Genéticamente
4.
Eur J Med Chem ; 191: 112118, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32113126

RESUMEN

Highly expressed in cancer 1 (Hec1) plays an essential role in mitosis and is correlated with cancer formation, progression, and survival. Phosphorylation of Hec1 by Nek2 kinase is essential for its mitotic function, thus any disruption of Hec1/Nek2 protein-protein interaction has potential for cancer therapy. We have developed T-1101 tosylate (9j tosylate, 9j formerly known as TAI-95), optimized from 4-aryl-N-pyridinylcarbonyl-2-aminothiazole of scaffold 9 by introducing various C-4' substituents to enhance potency and water solubility, as a first-in-class oral clinical candidate for Hec1 inhibition with potential for cancer therapy. T-1101 has good oral absorption, along with potent in vitro antiproliferative activity (IC50: 14.8-21.5 nM). It can achieve high concentrations in Huh-7 and MDA-MB-231 tumor tissues, and showed promise in antitumor activity in mice bearing human tumor xenografts of liver cancer (Huh-7), as well as of breast cancer (BT474, MDA-MB-231, and MCF7) with oral administration. Oral co-administration of T-1101 halved the dose of sorafenib (25 mg/kg to 12.5 mg/kg) required to exhibit comparable in vivo activity towards Huh-7 xenografts. Cellular events resulting from Hec1/Nek2 inhibition with T-1101 treatment include Nek2 degradation, chromosomal misalignment, and apoptotic cell death. A combination of T-1101 with either of doxorubicin, paclitaxel, and topotecan in select cancer cells also resulted in synergistic effects. Inactivity of T-1101 on non-cancerous cells, a panel of kinases, and hERG demonstrates cancer specificity, target specificity, and cardiac safety, respectively. Subsequent salt screening showed that T-1101 tosylate has good oral AUC (62.5 µM·h), bioavailability (F = 77.4%), and thermal stability. T-1101 tosylate is currently in phase I clinical trials as an orally administered drug for cancer therapy.


Asunto(s)
Antineoplásicos/farmacología , Proteínas del Citoesqueleto/antagonistas & inhibidores , Descubrimiento de Drogas , Quinasas Relacionadas con NIMA/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Proteínas del Citoesqueleto/metabolismo , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células K562 , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/metabolismo , Neoplasias Hepáticas Experimentales/patología , Ratones , Ratones SCID , Simulación del Acoplamiento Molecular , Estructura Molecular , Quinasas Relacionadas con NIMA/metabolismo , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Relación Estructura-Actividad , Distribución Tisular
5.
Plant Sci ; 289: 110277, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31623780

RESUMEN

Along with the species evolution, plants have evolved ways to produce a different collection of terpenoids to accommodate its biotic and abiotic environment, and terpene synthase (TPS) is one of the major contributors to various terpene compounds. The timber of a monotypic and relictual conifer species of Cupressace, Taiwania cryptomerioides, has excellent durability, and one of the essential factors for Taiwania to resist decay and insect pests is sesquiterpene. Compared to other conifers, Taiwania has much higher abundance of cadinene-type sesquiterpenes, and the presence of cedrene-type sesquiterpenes. To understand sesquiterpene biosynthesis in Taiwania, we functionally characterized 10 T. cryptomerioides TPSs (TcTPSs) in vivo or in planta, which could catalyze sesquiterpene formation and potentially are involved in biosynthesis of diverse sesquiterpenoids in Taiwania. The distant phylogenetic relationship and the intron loss event of TcTPSs correlate to the differentiation of chemical profile Taiwania compared to other conifers. Furthermore, we identified TcTPS3 and TcTPS12 as δ-cadinene synthase, and TcTPS6 as cedrol synthase, which demonstrates the important contributions of dynamic evolution in TPSs to the chemical diversity in plants. Combining with functional characterization and comparison of catalytic residues, we conclude at least three catalytic routes for sesquiterpene biosynthesis in this species, and the skeleton diversity has been expended in T. cryptomeriodes.


Asunto(s)
Transferasas Alquil y Aril/genética , Cupressaceae/genética , Proteínas de Plantas/genética , Sesquiterpenos/metabolismo , Transcriptoma , Transferasas Alquil y Aril/metabolismo , Cupressaceae/metabolismo , Filogenia , Proteínas de Plantas/metabolismo
6.
J Exp Biol ; 222(Pt 20)2019 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-31562186

RESUMEN

Spider silks are protein-based fibers that are incorporated into webs with the unique combination of high mechanical toughness and resistance to microbial degradation. While spiders are undoubtedly exposed to saprophytic microorganisms in their native habitats, such as the forest understory and bush, their silks have rarely been observed to decompose in either field or laboratory studies. We performed cross-streaking assays using silk from three spider species and four bacterial strains and found no inhibition zones, indicating the absence of antibacterial properties. We also cultured all bacteria directly upon silk in Luria-Bertani (LB) broth (full nutrients), phosphate-buffered saline (PBS; no nutrients) and nitrogen-free glucose broth (NFG; full nutrients, no nitrogen), and found that bacteria grew readily on silk in LB broth but not in PBS or NFG buffer. Our results indicate that spider silk's resistance to bacterial degradation is likely due to bacteriostatic rather than antibacterial mechanisms when nitrogen is inaccessible.


Asunto(s)
Bacterias/crecimiento & desarrollo , Nitrógeno/farmacología , Seda/metabolismo , Arañas/química , Animales , Bacterias/efectos de los fármacos , Pruebas de Sensibilidad Microbiana
7.
Plant J ; 100(6): 1254-1272, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31448467

RESUMEN

Taiwania cryptomerioides is a monotypic gymnosperm species, valued for the high decay resistance of its wood. This durability has been attributed to the abundance of terpenoids, especially the major diterpenoid metabolite ferruginol, with antifungal and antitermite activity. Specialized diterpenoid metabolism in gymnosperms primarily recruits bifunctional class-I/II diterpene synthases (diTPSs), whereas monofunctional class-II and class-I enzymes operate in angiosperms. In this study, we identified a previously unrecognized group of monofunctional diTPSs in T. cryptomerioides, which suggests a distinct evolutionary divergence of the diTPS family in this species. Specifically, five monofunctional diTPS functions not previously observed in gymnosperms were characterized, including monofunctional class-II enzymes forming labda-13-en-8-ol diphosphate (LPP, TcCPS2) and (+)-copalyl diphosphate (CPP, TcCPS4), and three class-I diTPSs producing biformene (TcKSL1), levopimaradiene (TcKSL3) and phyllocladanol (TcKSL5), respectively. Methyl jasmonate (MeJA) elicited the accumulation of levopimaradiene and the corresponding biosynthetic diTPS genes, TcCPS4 and TcKSL3, is consistent with a possible role in plant defense. Furthermore, TcCPS4 and TcKSL3 are likely to contribute to abietatriene biosynthesis via levopimaradiene as an intermediate in ferruginol biosynthesis in Taiwania. In conclusion, this study provides deeper insight into the functional landscape and molecular evolution of specialized diterpenoid metabolism in gymnosperms as a basis to better understand the role of these metabolites in tree chemical defense.


Asunto(s)
Cupressaceae/enzimología , Cupressaceae/genética , Cupressaceae/metabolismo , Cycadopsida/genética , Cycadopsida/metabolismo , Diterpenos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/metabolismo , Secuencia de Aminoácidos , Cupressaceae/clasificación , Escherichia coli/genética , Evolución Molecular , Fósiles , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Redes y Vías Metabólicas/genética , Proteínas Recombinantes , Análisis de Secuencia de Proteína , Transcriptoma
8.
J Nat Prod ; 81(5): 1162-1172, 2018 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-29746128

RESUMEN

Terpenoids are a large group of important secondary metabolites that are involved in a variety of physiological mechanisms, and many are used commercially in the cosmetics and pharmaceutical industries. During the past decade, the topic of seasonal variation in terpenoid biosynthesis has garnered increasing attention. Formosan sweet gum ( Liquidambar formosana Hance) is a deciduous tree species. The expression of terpene synthase and accumulation of terpenoids in leaves may vary in different seasons. Here, four sesquiterpene synthases (i.e., LfTPS01, LfTPS02, LfTPS03, and LfTPS04) and a bifunctional mono/sesquiterpene synthase ( LfTPS05) were identified from Formosan sweet gum. The gene expression of LfTPS01, LfTPS02, and LfTPS03 showed seasonal diversification, and, in addition, expression of LfTPS04 and LfTPS05 was induced by methyl jasmonate treatment. The major products LfTPS01, LfTPS02, LfTPS04, and LfTPS05 are hedycaryol, α-selinene, trans-ß-caryophyllene, α-copaene/δ-cadinene, and nerolidol/linalool, respectively. The data indicated that the sesquiterpenoid content in the essential oil of Formosan sweet gum leaves shows seasonal differences that were correlated to the sesquiterpene synthase gene expression.


Asunto(s)
Transferasas Alquil y Aril/genética , Expresión Génica/genética , Liquidambar/genética , Proteínas de Plantas/genética , Sesquiterpenos/metabolismo , Monoterpenos Acíclicos , Monoterpenos/metabolismo , Hojas de la Planta/genética , Sesquiterpenos Policíclicos , Estaciones del Año
9.
J Agric Food Chem ; 65(9): 1874-1886, 2017 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-28234464

RESUMEN

Antodia cinnamomea, a precious brown-rot fungus endemic to Taiwan, has pharmaceutical applications due to its diverse array of metabolites. The terpenoids found in A. cinnamomea contribute to its most important bioactivities. We identified several terpenoid compounds in A. cinnamomea and revealed that their content in mycelium and fruiting body were significantly different. Using next-generation sequencing and an in-house transcriptome database, we identified several terpene synthase (TPS) candidates. After sequence analysis and functional characterization, 10 out of 12 candidates were found to have single or multiple terpene synthesis functions. Most of the terpenoid compounds were found to confer important bioactivities. RT-PCR results showed a positive correlation between terpene synthase expression pattern and terpenoid content. In addition, we identified several modification enzyme candidates that may be involved in the postmodification of terpenoid compounds with a genomic DNA scaffold, and a putative genetic network.


Asunto(s)
Antrodia/metabolismo , Cuerpos Fructíferos de los Hongos/metabolismo , Redes Reguladoras de Genes , Micelio/genética , Terpenos/metabolismo , Antrodia/genética , Antrodia/crecimiento & desarrollo , Cuerpos Fructíferos de los Hongos/genética , Cuerpos Fructíferos de los Hongos/crecimiento & desarrollo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Micelio/crecimiento & desarrollo , Micelio/metabolismo , Transcriptoma
10.
Sci Rep ; 6: 38071, 2016 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-27934872

RESUMEN

Methyltransferases play crucial roles in many cellular processes, and various regulatory mechanisms have evolved to control their activities. For methyltransferases involved in biosynthetic pathways, regulation via feedback inhibition is a commonly employed strategy to prevent excessive accumulation of the pathways' end products. To date, no biosynthetic methyltransferases have been characterized by X-ray crystallography in complex with their corresponding end product. Here, we report the crystal structures of the glycine sarcosine N-methyltransferase from the halophilic archaeon Methanohalophilus portucalensis (MpGSMT), which represents the first structural elucidation of the GSMT methyltransferase family. As the first enzyme in the biosynthetic pathway of the osmoprotectant betaine, MpGSMT catalyzes N-methylation of glycine and sarcosine, and its activity is feedback-inhibited by the end product betaine. A structural analysis revealed that, despite the simultaneous presence of both substrate (sarcosine) and cofactor (S-adenosyl-L-homocysteine; SAH), the enzyme was likely crystallized in an inactive conformation, as additional structural changes are required to complete the active site assembly. Consistent with this interpretation, the bound SAH can be replaced by the methyl donor S-adenosyl-L-methionine without triggering the methylation reaction. Furthermore, the observed conformational state was found to harbor a betaine-binding site, suggesting that betaine may inhibit MpGSMT activity by trapping the enzyme in an inactive form. This work implicates a structural basis by which feedback inhibition of biosynthetic methyltransferases may be achieved.


Asunto(s)
Glicina N-Metiltransferasa/química , Glicina N-Metiltransferasa/metabolismo , Methanosarcinaceae/enzimología , Proteínas Arqueales/química , Proteínas Arqueales/metabolismo , Betaína/metabolismo , Dominio Catalítico , Cristalografía por Rayos X , Retroalimentación Fisiológica , Regulación de la Expresión Génica Arqueal , Regulación Enzimológica de la Expresión Génica , Glicina/metabolismo , Methanosarcinaceae/química , Metilación , Modelos Moleculares , Estructura Secundaria de Proteína , Sarcosina/metabolismo
11.
Food Funct ; 7(12): 4753-4763, 2016 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-27805229

RESUMEN

Mulberry has favorable antioxidant ability. Menopause is a major cause of osteoporosis in women, and it is partially associated with oxidative stress. Here, mulberry water extract (MWE) was fed to ovariectomic (OVX) rats to explore the potential effect of MWE on osteoporosis. The results revealed that plasma alkaline phosphatase (ALP) significantly decreased in the OVX rats after MWE administration for 8 weeks. Histological examination showed that the MWE increased the density of trabecular bone in the OVX rats. It also revealed that the MWE increases the expression of Runx2 and decreases that of the receptor activator of nuclear factor κB and its ligand in the OVX rats. This implies that MWE might regulate osteoblast differentiation and osteoclast proliferation. The MWE improved the antioxidant status by lowering the expression of heme oxygenase-1. In addition, the MWE increased the expression of osteocalcin, ALP, and bone morphogenetic protein-2 in an osteoblast cell line, MG-63. The present results imply that MWE has potential to decelerate osteoporosis in an experimental OVX rat model.


Asunto(s)
Morus/química , Extractos Vegetales/farmacología , Agua/química , Animales , Línea Celular , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Ovariectomía , Extractos Vegetales/química , Ratas , Ratas Sprague-Dawley
12.
J Nat Prod ; 78(7): 1556-62, 2015 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-26125648

RESUMEN

Antrodia cinnamomea is a scarce, epiphyte, host-specific, brown-rot fungus that produces diverse bioactive compounds with potent biological activity. Natural wild-type fruiting bodies of A. cinnamomea are rare and highly valued, but their artificial culture poses challenges. Triterpenoids are a group of secondary metabolites that contribute to the bioactivities of A. cinnamomea. 2,3-Oxidosqualene cyclase (OSC) is a key enzyme in triterpenoid biosynthesis, which converts 2,3-oxidosqualene (OS) into polycyclic triterpenoids. In this study, we isolated a 2,3-oxidosqualene cyclase gene from A. cinnamomea with degenerate primers and designated it as AcOSC. The full length AcOSC cDNA was subcloned into a yeast expression vector, and AcOSC activity was confirmed. RT-PCR results showed that AcOSC expression was highest in the wild-type fruiting body and correlated with a higher concentration of triterpenoids. Agrobacterium-mediated gene transformation was conducted to enhance the triterpenoid synthesis capacity of the cultured mycelium. Metabolite profiling was conducted by LC-MS/MS and principal component analysis (PCA). The compositions and contents of metabolites in the AcOSC transgenic lines were different from those in the wild-type mycelium and vector control. The levels of two important triterpenoids, dehydrosulphurenic acid (DSA) and dehydroeburicoic acid (DEA), were increased in A. cinnamomea oxidosqualene cyclase overexpression strains compared to controls. In summary an Agrobacterium-mediated gene transformation procedure was established that successfully increased the level of transgene expression and enhanced the triterpenoid content in cultured A. cinnamomea.


Asunto(s)
Antrodia/genética , Transferasas Intramoleculares/aislamiento & purificación , Triterpenos/metabolismo , Antrodia/química , Cuerpos Fructíferos de los Hongos/química , Cromatografía de Gases y Espectrometría de Masas , Humanos , Transferasas Intramoleculares/genética , Transferasas Intramoleculares/metabolismo , Estructura Molecular , Micelio , Escualeno/análogos & derivados , Escualeno/química , Taiwán
13.
PLoS One ; 10(4): e0123245, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25860872

RESUMEN

Antrodia cinnamomea, a precious, host-specific brown-rot fungus that has been used as a folk medicine in Taiwan for centuries is known to have diverse bioactive compounds with potent pharmaceutical activity. In this study, different fermentation states of A. cinnamomea (wild-type fruiting bodies and liquid cultured mycelium) were sequenced using the next-generation sequencing (NGS) technique. A 45.58 Mb genome encoding 6,522 predicted genes was obtained. High quality reads were assembled into a total of 13,109 unigenes. Using a previously constructed pipeline to search for microRNAs (miRNAs), we then identified 4 predicted conserved miRNA and 63 novel predicted miRNA-like small RNA (milRNA) candidates. Target prediction revealed several interesting proteins involved in tri-terpenoid synthesis, mating type recognition, chemical or physical sensory protein and transporters predicted to be regulated by the miRNAs and milRNAs.


Asunto(s)
Antrodia/crecimiento & desarrollo , Antrodia/genética , MicroARNs/genética , ARN de Hongos/genética , Antrodia/metabolismo , Secuencia de Bases , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Ontología de Genes , Genoma Fúngico , Secuenciación de Nucleótidos de Alto Rendimiento , MicroARNs/química , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN de Hongos/química
14.
Biosci Biotechnol Biochem ; 76(4): 646-51, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22484925

RESUMEN

Oxidative stress is the major contributor to acetaminophen (AAP)-caused liver damage. It promotes mitochondrial oxidative stress and collapses the mitochondrial membrane potential to cause cell death. We have previously shown that a polyphenol extract of Hibiscus sabdariffa L. (HPE) potentiated the antioxidative effect. We further examined in this study the possible mechanism of HPE against AAP-caused liver damage. BABL/c mice were orally fed with HPE (100, 200 or 300 mg/kg) for two weeks prior to an i.p. injection of 1000 mg/kg of AAP. The mice were decapitated 6 h after the AAP injection to collect the blood and liver for further determination. The results show that pretreating with HPE increased the level of glutathione (GSH), decreased the level of lipid peroxidation, and increased catalase activity in the liver. A histopathological evaluation shows that HPE could decrease AAP-induced liver sterosis accompanied by a decreased expression of AIF, Bax, Bid, and p-JNK in the liver. An in vitro assay revealed that HPE could reduce AAP-induced death of BABL/c normal liver cells (BNLs), reverse the lost mitochondrial potency and improve the antioxidative status, similarly to the results of the in vivo assay. We show in this study that HPE possessed the ability to protect the liver from AAP-caused injury. The protective mechanism might be regulated by decreasing oxidative stress and attenuating the mitochondrial dysfunction.


Asunto(s)
Acetaminofén/toxicidad , Hígado Graso/prevención & control , Hepatocitos/efectos de los fármacos , Hibiscus/química , Mitocondrias/efectos de los fármacos , Extractos Vegetales/uso terapéutico , Polifenoles/uso terapéutico , Animales , Antioxidantes/metabolismo , Proteínas Reguladoras de la Apoptosis , Catalasa/metabolismo , Muerte Celular/efectos de los fármacos , Hígado Graso/inducido químicamente , Glutatión/metabolismo , Hepatocitos/metabolismo , Hepatocitos/patología , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Mitocondrias/metabolismo , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Polifenoles/administración & dosificación
15.
Int J Med Mushrooms ; 13(6): 513-23, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22181839

RESUMEN

Medicinal mushroom Antrodia cinnamomea is a higher Basidiomycetes endemic to Taiwan, where it is commonly used as a traditional folk medicine. It is well known for its multiple biologic activities and its potential for commercial development. Here, ten full lengths of cytochrome P450 (CYP) genes (ac-1 to ac-10) from A. cinnamomea were cloned and identified. With the exception of ac-3 and ac-8, which will probably be assigned as new CYP families, these genes had more than 40% amino acid identity and close evolutionary relationships to known CYPs. Among the ten genes, only Ac-7 did not possess a transmembrane domain but had an N-terminal signal peptide, so it was considered a novel extracellular CYP. The ten A. cinnamomea CYPs had different expression profiles in different growth conditions. In general, they were strongly expressed during the formation of fruiting bodies, especially in natural basidiomycetes. The expression of six CYPs of A. cinnamomea (ac-1 to ac-3 and ac-5 to ac-7) were strictly inhibited in the mycelia cell type. It was therefore concluded that these CYPs are most active in the fruiting bodies of A. cinnamomea.


Asunto(s)
Antrodia/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Cuerpos Fructíferos de los Hongos/crecimiento & desarrollo , Cuerpos Fructíferos de los Hongos/metabolismo , Regulación Fúngica de la Expresión Génica/fisiología , Secuencia de Aminoácidos , Clonación Molecular , ADN Complementario/genética , ADN de Hongos/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Perfilación de la Expresión Génica , Modelos Moleculares , Anotación de Secuencia Molecular , Filogeografía , Conformación Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
16.
Artículo en Inglés | MEDLINE | ID: mdl-18955361

RESUMEN

Antrodia camphorata is used in folk medicine for the treatment of inflammation syndromes and liver-related diseases in Taiwan. The goal of this study was to evaluate the efficacy of the mycelial extract of A. camphorata (ACE) for the treatment of systemic lupus erythematosus (SLE) in SLE-prone NZB/W F1 mice. After antibodies against double-stranded DNA appeared in NZB/W mice, the mice were orally administered varying dosages of ACE (100, 200 and 400 mg kg(-1)) for 5 consecutive days per week for 12 weeks via gavage. To assess the efficacy of ACE, we measured SLE-associated biochemical and histopathological biomarkers levels of blood urine nitrogen (BUN), blood creatinine, urine protein and urine creatinine and thickness of the kidney glomerular basement membrane by staining with periodic acid-Schiff. Antroquinonol, an active component of ACE, was investigated for anti-inflammation activity in lipopolysaccharide-induced RAW 267.4 cells. ACE at 400 mg kg(-1) significantly suppressed urine protein and serum BUN levels and decreased the thickness of the kidney glomerular basement membrane. Antroquinonol significantly inhibited the production of tumor necrosis factor-α and interleukin-1ß by 75 and 78%, respectively. In conclusion, ACE reduced urine protein and creatinine levels and suppressed the thickening of the kidney glomerular basement membrane, suggesting that ACE protects the kidney from immunological damage resulting from autoimmune disease.

17.
Cell Biochem Funct ; 28(7): 549-54, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20818598

RESUMEN

In cultured cells, glucose and serum provide constant sources of energy and growth factors, both of which are important for cell survival and proliferation. AMP-activated protein kinase (AMPK) plays a key role in sensing intracellular ATP levels and acts as a critical regulator of energy homeostasis. To investigate the relationship between energy status and AMPK activity in lung cancer, H460 cells were starved in either glucose-free or serum-free medium and then re-stimulated with glucose and serum, respectively. The levels of ATP and lactate and the activities of AMPK and lactate dehydrogenase (LDH) were analyzed at different time intervals. During glucose treatment, the activity of AMPK was induced by glucose and showed biphasic reaction kinetics. The ATP level was gradually increased up to 2-fold compared with that in serum treatment after 24 h and lactate level was decreased to approximately 60%. The LDH activity slightly increased and reached a peak after 6 h. During serum treatment, the activity of AMPK was suppressed and the ATP level showed a dramatic 30% increase after 1 h. In contrast, the lactate level was gradually increased and then reverted to the background level after 24 h. The activity of LDH was slightly decreased after 12 h and eventually returned to the background level. This study showed the alteration of energy status in lung cancer cells in response to altered levels of glucose and serum. We suggest that the activation of AMPK and inhibition of glycolysis might be exploited as therapeutic tactics in cancer treatment.


Asunto(s)
Metabolismo Energético/fisiología , Neoplasias Pulmonares/metabolismo , Proteínas Quinasas Activadas por AMP , Adenosina Trifosfato/metabolismo , Línea Celular Tumoral , Medio de Cultivo Libre de Suero , Regulación hacia Abajo , Glucosa/metabolismo , Humanos , Cinética , Lactato Deshidrogenasas/metabolismo , Ácido Láctico/metabolismo , Regulación hacia Arriba
18.
Mol Carcinog ; 49(8): 728-38, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20623640

RESUMEN

The aim of this study was to test whether long-term ethanol consumption confers therapeutic resistance to human liver cancer patients infected with hepatitis B virus (HBV). Chronic ethanol-treated cells were established by consecutively culturing a human hepatocellular carcinoma cell line, Hep 3B, which contains integrated HBV sequences, for 20-40 passages with or without 10 mM ethanol (designated as E20-E40 and C20-C40, respectively). Flow cytometry analysis demonstrated that a growth promoting effect of long-term ethanol treatment was induced in the E40 cells through preferential acceleration of S-phase in these cells. Lower protein expression levels of p16, p21/Cip1, and p27/Kip1 were detected in the ethanol-treated E40 cells. We further demonstrated that long-term ethanol-treated E40 cells develop drug resistance in response to mitomycin C (MMC) treatment (>8 microM). Immunoblot analysis revealed that caspase-8-mediated mitochondrial apoptotic signals (such as Bad) were inactivated in the MMC-resistant E40 cells. Immunoprecipitation experiments demonstrated that the sequestration of phosphorylated Bad (Ser-112) through its binding with 14-3-3 was detected more profoundly in the MMC-resistant E40 cells. Next, we examined the therapeutic efficacy of MMC (10 mg MMC/kg body weight, three times per week) in severe combined immunodeficient (SCID) mice bearing E40- and C40-xenografted tumors. Significant reductions (>3-fold) in tumor growth were detected in MMC-treated C40-xenografted mice. In vivo and in vitro studies demonstrated that AKT- and extracellular signal-regulated kinase (ERK)-mediated survival factors inhibited the Bad-induced mitochondrial apoptotic signals that were involved in E40 tumor cells and that conferred resistance to MMC.


Asunto(s)
Mitomicina/farmacología , Mitomicina/uso terapéutico , Apoptosis/efectos de los fármacos , Caspasa 8/metabolismo , Etanol/metabolismo , Etanol/farmacología , Citometría de Flujo , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/metabolismo , Mitocondrias/metabolismo , Mitomicina/metabolismo , Estilbenos
19.
FEMS Microbiol Lett ; 280(2): 150-9, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18218021

RESUMEN

cDNAs specifically expressed at the basidiome stage were isolated by using PCR-selected cDNA subtraction in order to study gene regulation during porous-hymenium basidiomatal formation in Antrodia cinnamomea. blastx results suggested that most of the expressed sequence tags (52.4-69.5%) had no significant protein homology to genes from other published living things. cDNAs particularly expressed at different growing conditions were identified using cDNA microarray analysis. Reverse transcriptase PCR analyses confirmed that the clone putative to P-type ATPase, various cytochrome P450s and some unknown genes were abundant at natural basidiomes while endoglucanase was abundant at the tissue from artificial medium.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/fisiología , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Polyporales/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Genes Fúngicos/fisiología , Polyporales/genética , Polyporales/crecimiento & desarrollo , ARN Mensajero/metabolismo , Análisis de Secuencia de ADN , Técnica de Sustracción , Transcripción Genética/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...