167 research outputs found
Bioactive Peptides from Angelica sinensis
Since excessive reactive oxygen species (ROS) is known to be associated with aging and age-related diseases, strategies modulating ROS level and antioxidant defense systems may contribute to the delay of senescence. Here we show that the protein hydrolyzate from Angelica sinensis was capable of increasing oxidative survival of the model animal Caenorhabditis elegans intoxicated by paraquat. The hydrolyzate was then fractionated by ultrafiltration, and the antioxidant fraction (<3 kDa) was purified by gel filtration to obtain the antioxidant A. sinensis peptides (AsiPeps), which were mostly composed of peptides with <20 amino acid residues. Further studies demonstrate that AsiPeps were able to reduce the endogenous ROS level, increase the activities of the antioxidant enzymes superoxide dismutase and catalase, and decrease the content of the lipid peroxidation product malondialdehyde in nematodes treated with paraquat or undergoing senescence. AsiPeps were also shown to reduce age pigments accumulation and extend lifespan but did not affect the food-intake behavior of the nematodes. Taken together, our results demonstrate that A. sinensis peptides (AsiPeps) are able to delay aging process in C. elegans through antioxidant activities independent of dietary restriction
In-plane hyperbolic polariton tuners in terahertz and long-wave infrared regimes
Development of terahertz (THz) and long-wave infrared (LWIR) technologies is
mainly bottlenecked by the limited intrinsic response of traditional materials.
Hyperbolic phonon polaritons (HPhPs) of van der Waals semiconductors couple
strongly with THz and LWIR radiation. However, the mismatch of photon-polariton
momentum makes far-field excitation of HPhPs challenging. Here, we propose an
In-Plane Hyperbolic Polariton Tuner that is based on patterning van der Waals
semiconductors, here {\alpha}-MoO3, into ribbon arrays. We demonstrate that
such tuners respond directly to far-field excitation and give rise to LWIR and
THz resonances with high quality factors up to 300, which are strongly
dependent on in-plane hyperbolic polariton of the patterned {\alpha}-MoO3. We
further show that with this tuner, intensity regulation of reflected and
transmitted electromagnetic waves, as well as their wavelength and polarization
selection can be achieved. This is important to development of THz and LWIR
miniaturized devices
Tanshinone IIA Inhibits Glutamate-Induced Oxidative Toxicity through Prevention of Mitochondrial Dysfunction and Suppression of MAPK Activation in SH-SY5Y Human Neuroblastoma Cells
Glutamate excitotoxicity is associated with many neurological diseases, including cerebral ischemia and neurodegenerative diseases. Tanshinone IIA, a diterpenoid naphthoquinone from Salvia miltiorrhiza, has been shown to suppress presynaptic glutamate release, but its protective mechanism against glutamate-induced neurotoxicity is lacking. Using SH-SY5Y human neuroblastoma cells, we show here that excessive glutamate exposure decreases cell viability and proliferation and increases LDH release. Pretreatment with tanshinone IIA, however, prevents the decrease in cell viability and proliferation and the increase in LDH release induced by glutamate. Tanshinone IIA also attenuates glutamate-induced oxidative stress by reducing reactive oxygen species level and malondialdehyde and protein carbonyl contents and by enhancing activities and protein levels of superoxide dismutase and catalase. We then show that tanshinone IIA prevents glutamate-induced mitochondrial dysfunction by increasing mitochondrial membrane potential and ATP content and by reducing mitochondrial protein carbonyl content. Moreover, tanshinone IIA can inhibit glutamate-induced apoptosis through regulation of apoptosis-related protein expression and MAPK activation, including elevation of Bcl-2 protein level, decrease in Bax and cleaved caspase-3 levels, and suppression of JNK and p38 MAPK activation. Collectively, our findings demonstrate that tanshinone IIA protects SH-SY5Y cells against glutamate toxicity by reducing oxidative stress and regulating apoptosis and MAPK pathways
Omics Insights into Metabolic Stress and Resilience of Rats in Response to Short-term Fructose Overfeeding.
SCOPE:Considerable evidence supports the view that high-fructose intake is associated with increased and early incidence of obesity and dyslipidemia. However, knowledge on physiopathological alterations introduced by fructose overconsumption is lacking. We have therefore carried out an integrated omics analysis to investigate the consequences of short-term fructose overfeeding(SFO) and identify the underlying molecular mechanisms. METHODS AND RESULTS:SFO of rats demonstrated obvious histopathological hepatic lipid accumulation and significant elevation in adiposity, total cholesterol and fasting plasma glucose levels. Integrated omics analysis demonstrated that SFO disturbed metabolic homeostasis and initiated metabolic stress. Hepatic lipogenesis pathways were also negatively impacted by SFO. Analysis of molecular networks generated by IPA implicated involvement of the ERK signaling pathway in SFO and its consequences. Moreover, we identified that an inherent negative feedback regulation of hepatic SREBP1 plays an active role in regulating hepatic de novo lipogenesis. CONCLUSION:Our findings indicate that SFO disturbs metabolic homeostasis and that endogenous small molecules positively mediate SFO induced metabolic adaption. Our results also underline that an inherent regulatory mechanism of resilience occurs in response to fructose overconsumption, suggesting that efforts to maintain resilience could be a promising target to prevent and treat metabolic disorder-like conditions. This article is protected by copyright. All rights reserved
A four-microRNA panel in serum may serve as potential biomarker for renal cell carcinoma diagnosis
BackgroundRenal cell carcinoma (RCC) is one out of the most universal malignant tumors globally, and its incidence is increasing annually. MicroRNA (miRNA) in serum could be considered as a non-invasive detecting biomarker for RCC diagnosis.MethodA total of 224 participants (112 RCC patients (RCCs) and 112 normal controls (NCs)) were enrolled in the three-phrase study. Reverse transcription quantitative PCR (RT-qPCR) was applied to reveal the miRNA expression levels in RCCs and NCs. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were utilized to predict the diagnostic ability of serum miRNAs for RCC. Bioinformatic analysis and survival analysis were also included in our study.ResultsCompared to NCs, the expression degree of miR-155-5p, miR-224-5p in serum was significantly upregulated in RCC patients, and miR-1-3p, miR-124-3p, miR-129-5p, and miR-200b-3p were downregulated. A four-miRNA panel was construed, and the AUC of the panel was 0.903 (95% CI: 0.847–0.944; p < 0.001; sensitivity = 75.61%, specificity = 93.67%). Results from GEPIA database indicated that CHL1, MPP5, and SORT1 could be seen as promising target genes of the four-miRNA panel. Survival analysis of candidate miRNAs manifested that miR-155-5p was associated with the survival rate of RCC significantly.ConclusionsThe four-miRNA panel in serum has a great potential to be non-invasive biomarkers for RCC sift to check
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
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