RESUMEN

BACKGROUND/PURPOSE: Myocarditis is a severe disorder characterized by the inflammation of the heart's muscular walls, thereby leading to sudden death in young adults. Long non-coding RNA X-inactive specific transcripts (LncRNA XIST) are a class of transcripts having a length ˃ 200 nts with the absence of protein-coding abilities. They exert their function of apoptosis in various cancers and inflammatory diseases. OBJECTIVE: The current work intended to investigate the impact and mechanism of XIST on inflammation induced by LPS in AC16 cells. METHODS: An in vitro inflammatory injury model was established by stimulating AC16 cells with LPS. CCK-8 was used to test AC16 cell viability and FCM to detect apoptosis. The Elisa assay was used to measure the level of IL-8, IL-1ß, and TNF-α. The RT-qPCR was used to detect XIST, miR-370-3p, Bax, and Bcl-2 in LPS-stimulated AC16 cells. The Elisa assay was performed to assess the phosphorylation of PI3K, AKT and mTOR in AC16 cells. RESULTS: Our findings showed LPS exposure to significantly reduce AC16 cell viability while increasing inflammation and apoptosis. Also, XIST expression was reduced in AC16 cells stimulated with LPS. Overexpression of XIST in AC16 cells increased cell survival, inhibited apoptosis, and increased the expressions of Bcl-2, Bax, and inflammatory modulators (IL-8, TNF-α, and IL-1ß). Inhibiting XIST in AC16 cells produced opposite outcomes. MiR-370-3p mimics inhibited XIST's effect on inflammation, viability, and apoptosis. Moreover, XIST inhibited the phosphorylation levels of mTOR, AKT, and PI3K in LPS-injured AC16 cells. CONCLUSION: The data elucidate lncRNA XIST to exert its anti-inflammatory and anti-apoptotic effects on AC16 cells stimulated by LPS via down-regulating miR-370-3p and inhibiting PI3K/AKT/mTOR pathways. These findings suggest a novel treatment strategy for myocarditis.

RESUMEN

As part of our search for new cytotoxic and antimicrobial natural products from endolichenic fungi, 19 compounds including 1 new 10-member lactone (2: ), 1 new polyacetylene glycoside (3: ), 1 new brasilane-type sesquiterpenoid glycoside (4: ), and 2 isobenzofuran-1(3H)-one derivatives (5: and 6: ) were isolated from the solid culture of the endolichenic fungus Hypoxylon fuscum. Their structures were unambiguously elucidated by NMR spectroscopic data, MS, ECD (electronic circular dichroism) calculation, and chemical methods. The cytotoxic effects on K562, SW480, and HEPG2 cell lines and the antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Candida albicans were assessed. Compounds 1, 2: , and 5: exhibited moderate cytotoxicity against K562, SW480, and HEPG2 cell lines while compounds 1, 9: , and 11: displayed weak antibacterial activity against S. aureus.

Asunto(s)

Citotoxinas/aislamiento & purificación , Xylariales/metabolismo , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Bacillus subtilis/efectos de los fármacos , Candida albicans/efectos de los fármacos , Línea Celular Tumoral/efectos de los fármacos , Dicroismo Circular , Citotoxinas/farmacología , Escherichia coli/efectos de los fármacos , Células Hep G2/efectos de los fármacos , Humanos , Células K562/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Staphylococcus aureus/efectos de los fármacos , Xylariales/química

RESUMEN

Two new arborinane-type triterpenes, myrotheols A (1: ) and B (2: ), two new arborinane-type glycosides, myrothesides C (3: ) and D (4: ), together with four known diterpenes (5:  - 8: ) were isolated from the ethyl acetate extract of the endolichenic fungus Myrothecium inundatum. The structures of new compounds 1:  - 4: were elucidated by NMR and MS analyses. The absolute configuration of 1: was assigned by a single-crystal X-ray diffraction experiment. Compounds 3: and 4: represent the first two natural 4-O-methyl-α-D-mannosides. Compounds 1:  - 8: exhibited cytotoxicity against K562 and RKO human cancer cell lines.

Asunto(s)

Antineoplásicos/farmacología , Hypocreales/química , Triterpenos/química , Triterpenos/farmacología , Antineoplásicos/química , Línea Celular Tumoral , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células K562 , Líquenes/microbiología , Espectroscopía de Resonancia Magnética , Estructura Molecular , Triterpenos/aislamiento & purificación

RESUMEN

Curcumin, which is the effective component of turmeric (Curcuma longa), has previously been shown to exert potent antioxidant, antitumor and anti­inflammatory activities in vitro and in vivo. However, the mechanism underlying the protective effects of curcumin against oxidative damage in endothelial cells remains unclear. The present study aimed to examine the effects of curcumin on hydrogen peroxide (H2O2)­induced apoptosis and autophagy in EA.hy926 cells, and to determine the underlying molecular mechanism. Cultured EA.hy926 cells were treated with curcumin (5­20 µmol/l) 4 h prior to and for 4 h during exposure to H2O2 (200 µmol/l). Oxidative stress resulted in a significant increase in the rate of cell apoptosis, which was accompanied by an increase in the expression levels of caspase­3 and B­cell lymphoma 2 (Bcl­2)­associated X protein (Bax), and a decrease in the expression levels of Bcl­2. Treatment with curcumin (5 or 20 µmol/l) significantly inhibited apoptosis, and reversed the alterations in caspase­3, Bcl­2 and Bax expression. Furthermore, curcumin induced autophagy and microtubule­associated protein 1A/1B­light chain 3­â…¡ expression, and suppressed the phosphorylation of Akt and mammalian target of rapamycin (mTOR). These results indicated that curcumin may protect cells against oxidative stress­induced damage through inhibiting apoptosis and inducing autophagy via the Akt/mTOR pathway.

Asunto(s)

Autofagia/efectos de los fármacos , Curcumina/farmacología , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citoprotección/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Humanos , Peróxido de Hidrógeno/toxicidad , Fosforilación

RESUMEN

p27(kip1) (p27) is widely known as a potent cell cycle inhibitor in several organs, especially in the heart. However, its role has not been fully defined during the early phase of myocardial infarction (MI). In this study, we investigated the relationships between p27, vascular endothelial growth factor/hepatocyte growth factor (VEGF/HGF) and NF-κB in post-MI cardiac function repair both in vivo and in the hypoxia/ischemia-induced rat myocardiocyte model. In vivo, haplo-insufficiency of p27 improved cardiac function, diminished the infarct zone, protected myocardiocytes and increased angiogenesis by enhancing the production of VEGF/HGF. In vitro, the presence of conditioned medium from hypoxia/ischemia-induced p27 knockdown myocardiocytes reduced the injury caused by hypoxia/ischemia in myocardiocytes, and this effect was reversed by VEGF/HGF neutralizing antibodies, consistent with the cardioprotection being due to VEGF/HGF secretion. We also observed that p27 bound to IKK and that p27 haplo-insufficiency promoted IKK/p65 activation both in vivo and in vitro, thereby inducing the NF-κB downstream regulator, VEGF/HGF. Furthermore, IKKi and IKK inhibitor negated the effect of VEGF/HGF. Therefore, we conclude that p27 haplo-insufficiency protects against heart injury by VEGF/HGF mediated cardioprotection and increased angiogenesis through promoting IKK activation.

Asunto(s)

Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Haploinsuficiencia , Factor de Crecimiento de Hepatocito/genética , Infarto del Miocardio/genética , Miocardio/metabolismo , Neovascularización Fisiológica , Factor A de Crecimiento Endotelial Vascular/genética , Animales , Anticuerpos Neutralizantes/farmacología , Hipoxia de la Célula , Línea Celular , Medios de Cultivo Condicionados/farmacología , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/antagonistas & inhibidores , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Endotelio Vascular/enzimología , Endotelio Vascular/patología , Activación Enzimática , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Haplotipos , Factor de Crecimiento de Hepatocito/antagonistas & inhibidores , Factor de Crecimiento de Hepatocito/metabolismo , Quinasa I-kappa B/genética , Quinasa I-kappa B/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/enzimología , Infarto del Miocardio/patología , Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , FN-kappa B/genética , FN-kappa B/metabolismo , Ratas , Transducción de Señal , Factores de Tiempo , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/metabolismo

RESUMEN

Differences in rates of nucleotide or amino acid substitutions among major groups of organisms are repeatedly found and well documented. A growing body of evidence suggests a link between the rate of neutral molecular change within populations and the evolution of species diversity. More than 98% of terrestrial fungi belong to the phyla Ascomycota or Basidiomycota. The former is considerably richer in number of species than the latter. We obtained DNA sequences of 21 protein-coding genes from the lichenized fungus Rhizoplaca chrysoleuca and used them together with sequences from GenBank for subsequent analyses. Three datasets were used to test rate discrepancies between Ascomycota and Basidiomycota and that within Ascomycota: (i) 13 taxa including 105 protein-coding genes, (ii) nine taxa including 21 protein-coding genes, and (iii) nuclear LSU rDNA of 299 fungal species. Based on analyses of the 105 protein-coding genes and nuclear LSU rDNA datasets, we found that the evolutionary rate was higher in Ascomycota than in Basidiomycota. The differences in substitution rates between Ascomycota and Basidiomycota were significant. Within Ascomycota, the species-rich Sordariomycetes has the fastest evolutionary rate, while Leotiomycetes has the slowest. Our results indicate that the main contribution to the higher substitution rates in Ascomycota does not come from mutualism, ecological conditions, sterility, metabolic rate or shorter generation time, but is possibly caused by the founder effect. This is another example of the correlation between species number and evolutionary rates, which is consistent with the hypothesis that the founder effect is responsible for accelerated substitution rates in diverse clades.

Asunto(s)

Ascomicetos/clasificación , Ascomicetos/genética , Basidiomycota/clasificación , Basidiomycota/genética , Evolución Molecular , ADN de Hongos/genética , Bases de Datos de Ácidos Nucleicos , Proteínas Fúngicas/genética , Genes Fúngicos , Variación Genética , Especificidad de la Especie , Factores de Tiempo

RESUMEN

Specimens of Rhizoplaca chrysoleuca from Mount Wuling can be divided into two distinct groups based on obvious differences in morphological characters. Here we investigated 26 specimens of R. chrysoleuca from Mount Wuling, 10 specimens of this species from other areas and seven specimens of other Rhizoplaca species by analyzing morphology, chemistry and genetics. Nine chemotypes were detected among the specimens of R. chrysoleuca from Mount Wuling, and five of them were reported for the first time. Based on the ITS phylogenetic analysis, the chemotypes and the insertion distribution patterns in SSU rDNA, the samples of R. chrysoleuca from Mount Wuling were grouped in two distinct clades corresponding to two phenotypic groups and no gene flow was detected between these two groups. Our results establish all individuals of Rhizoplaca chrysoleuca are conspecific although some populations have been isolated on Mount Wuling, indicating that they are in the process of speciation. Our study also reveals that the relationships between genotypes and chemotypes are complicated and should be avoided, and we instead recommend using single individuals or few individuals from the same site to represent the population or whole species in systematics study. The results also indicate that Rhizoplaca chrysoleuca might provide a good model for studying the speciation of saxicolous lichenized fungi.

Asunto(s)

Ascomicetos/clasificación , Ascomicetos/genética , Variación Genética , Ascomicetos/química , Benzofuranos/análisis , Cromatografía en Capa Delgada , ADN de Hongos/química , ADN de Hongos/genética , ADN de Hongos/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Ribosómico/aislamiento & purificación , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , ADN Espaciador Ribosómico/aislamiento & purificación , Genes de ARNr/genética , Hidroxibenzoatos/análisis , Intrones/genética , Datos de Secuencia Molecular , Filogenia , ARN de Hongos/genética , ARN Ribosómico/genética , Salicilatos/análisis , Análisis de Secuencia de ADN