RESUMEN
Cells limit energy-consuming mRNA translation during stress to maintain metabolic homeostasis. Sequestration of mRNAs by RNA binding proteins (RBPs) into RNA granules reduces their translation, but it remains unclear whether RBPs also function in partitioning of specific transcripts to polysomes (PSs) to guide selective translation and stress adaptation in cancer. To study transcript partitioning under cell stress, we catalogued mRNAs enriched in prostate carcinoma PC-3 cell PSs, as defined by polysome fractionation and RNA sequencing (RNAseq), and compared them to mRNAs complexed with the known SG-nucleator protein, G3BP1, as defined by spatially-restricted enzymatic tagging and RNAseq. By comparing these compartments before and after short-term arsenite-induced oxidative stress, we identified three major categories of transcripts, namely those that were G3BP1-associated and PS-depleted, G3BP1-dissociated and PS-enriched, and G3BP1-associated but also PS-enriched. Oxidative stress profoundly altered the partitioning of transcripts between these compartments. Under arsenite stress, G3BP1-associated and PS-depleted transcripts correlated with reduced expression of encoded mitochondrial proteins, PS-enriched transcripts that disassociated from G3BP1 encoded cell cycle and cytoprotective proteins whose expression increased, while transcripts that were both G3BP1-associated and PS-enriched encoded proteins involved in diverse stress response pathways. Therefore, G3BP1 guides transcript partitioning to reprogram mRNA translation and support stress adaptation.
Asunto(s)
ADN Helicasas/genética , Estrés Oxidativo/genética , Proteínas de Unión a Poli-ADP-Ribosa/genética , Biosíntesis de Proteínas/genética , ARN Helicasas/genética , Proteínas con Motivos de Reconocimiento de ARN/genética , ARN Mensajero/genética , Arsenitos/toxicidad , Carcinoma/genética , Carcinoma/metabolismo , Gránulos Citoplasmáticos/genética , Metabolismo Energético/genética , Humanos , Masculino , Estrés Oxidativo/efectos de los fármacos , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Proteínas de Unión al ARN/genéticaRESUMEN
In this study, an in vitro tyrosinase inhibition assay in combination with ultra performance liquid chromatography-orbitrap mass spectrometry (UPLC-orbitrap-MS) was developed for the rapid screening and identification of tyrosinase modulators from roots of Angelica keiskei. Of the 15 candidates considered, nine chalcones, xanthoangelols (1), B (2), D (3), E (4), G (5), H (6), 4-hydroxyderricin (7), xanthokeismin B (8) and (2E)-1-[4-hydroxy-2-(2-hydroxy-2-propanyl)-2,3-dihydro-1-benzofuran-7-yl]-3-(4-hydroxyphenyl)-2-propen-1-one (9), five coumarins, umbelliferone (10), selinidin (11), isopimpinellin (12), phellopterin (13) and xanthyletin (14), and one other compound, ashitabaol A (15), were distinguished between the test samples and the controls with statistical significance, and the structure of each compound was determined by comparing with in-house standards and the literature. Among these, six compounds, xanthoangelol (1), xanthoangelol D (3), xanthoangelol H (6), 4-hydroxyderricin (7), laserpitin (16) and isolaserpitin (17), were isolated from roots of A. keiskei. Of the compounds isolated, compounds 1, 7 and 16 were subjected to tyrosinase inhibitory assay, and the IC50 values were 15.87 ± 1.21, 60.14 ± 2.29 and >100 µM, respectively. The present study indicated that the combination of in vitro tyrosinase inhibition assay coupled with UPLC-MS/MS could be widely applied to the rapid screening of active substances from various natural resources.
Asunto(s)
Angelica/química , Inhibidores Enzimáticos/química , Monofenol Monooxigenasa/química , Raíces de Plantas/química , Chalcona/análogos & derivados , Chalcona/química , Chalconas/química , Cromatografía Liquida , Cumarinas/química , Inhibidores Enzimáticos/farmacología , Monofenol Monooxigenasa/antagonistas & inhibidores , Espectrometría de Masas en Tándem , Umbeliferonas/químicaRESUMEN
AIMS: Changes in emotions associated with mountain treks have rarely been reported. This study examined emotional state changes in sixth-grade elementary school students before and after a 3-day high-altitude mountain trek from the trailhead (2140 m) to Xue Mountain (3886 m) in Taiwan. METHODS: In June 2011, 201 students participated in the trek. The round-trip distance was 21.8 km. The age, gender, blood group, and family configuration of the participants were documented before the trek. A 36-item short-form survey instrument, including the Mood and Anxiety Symptom Questionnaire and the Positive and Negative Affect Scale for Children, was used to evaluate the participants' emotional states (happiness, anticipation, sadness, and anger). The participants answered the questionnaires 1 month before and 1 week after the trek. A Likert scale was used to evaluate individual items (range 1-4; from strongly disagree to strongly agree). We calculated scores for each index before and after the trek. The incidence and presentation of acute mountain sickness (AMS) among the participants was also studied and published previously. RESULTS: In total, 187 (112 boys and 75 girls) participants (mean age 11.9 ± 0.4 years) completed the trek and the survey. The sadness and anger scores (negative emotions) were significantly lower after than before the trek (39.5 vs. 36.6; p < 0.01). The happiness and anticipation scores (positive emotions) before and after the trek did not differ significantly (49.9 vs. 48.9; p = 0.11). No participant used AMS prophylaxis, while 78 participants met the AMS criteria. Negative emotions decreased more in those with AMS than without AMS (-4.6 vs. -1.8; p = 0.04), and the use of medications or acetazolamide did not alter the emotions. CONCLUSIONS: A 3-day high-altitude mountain trek can reduce children's negative emotions. Negative emotions decreased more in those with AMS, whereas medications or acetazolamide did not alter their emotions.
Asunto(s)
Mal de Altura/psicología , Altitud , Emociones , Montañismo/psicología , Negativismo , Mal de Altura/etiología , Niño , Femenino , Humanos , Masculino , Estudios Prospectivos , Escalas de Valoración Psiquiátrica , TaiwánRESUMEN
Chamaecyparis formosensis is Taiwan's most representative tree, and has high economic value. To date, only a few active chemical constituents have been reported for C. formosensis. In this study, 37 secondary metabolites, including three new compounds (1-3), were extracted from the leaves of C. formosensis. The compounds isolated from the ethyl acetate layer were used at different concentrations to treat HT-1080 human fibrosarcoma cells and to evaluate their effects on matrix metalloprotease 2 (MMP-2) and 9 (MMP-9) expression. Based on extensive analysis of data from high-resolution mass spectrometry (HR-MS) as well as nuclear magnetic resonance (NMR), infrared (IR), and ultraviolet (UV) spectroscopy, the new compounds were identified as 11,12-dihydroxyisodaucenoic acid (1), 12-hydroxyisodaucenoic acid (2), and 1-oxo-2α,3ß-dihydroxytotarol (3). Known compounds 4-37 were identified by comparing their spectroscopic data with data reported in the literature. Biological activity tests by gelatin zymographic analysis revealed that seven compounds, including new compound 2, have no cytotoxic effect on HT-1080 cells and were found to increase MMP-2 or MMP-9 expression by 1.25- to 1.59-fold at lower concentrations of 10-50 µM. These naturally derived regulatory compounds could potentially serve as a novel pharmaceutical basis for medical purposes.