974 research outputs found
SIRT3 Protects Rotenone-induced Injury in SH-SY5Y Cells by Promoting Autophagy through the LKB1-AMPK-mTOR Pathway.
SIRT3 is a class III histone deacetylase that modulates energy metabolism, genomic stability and stress resistance. It has been implicated as a potential therapeutic target in a variety of neurodegenerative diseases, including Parkinson's disease (PD). Our previous study demonstrates that SIRT3 had a neuroprotective effect on a rotenone-induced PD cell model, however, the exact mechanism is unknown. In this study, we investigated the underlying mechanism. We established a SIRT3 stable overexpression cell line using lentivirus infection in SH-SY5Y cells. Then, a PD cell model was established using rotenone. Our data demonstrate that overexpression of SIRT3 increased the level of the autophagy markers LC3 II and Beclin 1. After addition of the autophagy inhibitor 3-MA, the protective effect of SIRT3 diminished: the cell viability decreased, while the apoptosis rate increased; α-synuclein accumulation enhanced; ROS production increased; antioxidants levels, including SOD and GSH, decreased; and MMP collapsed. These results reveal that SIRT3 has neuroprotective effects on a PD cell model by up-regulating autophagy. Furthermore, SIRT3 overexpression also promoted LKB1 phosphorylation, followed by activation of AMPK and decreased phosphorylation of mTOR. These results suggest that the LKB1-AMPK-mTOR pathway has a role in induction of autophagy. Together, our findings indicate a novel mechanism by which SIRT3 protects a rotenone-induced PD cell model through the regulation of autophagy, which, in part, is mediated by activation of the LKB1-AMPK-mTOR pathway
Systematic identification of genes involved in divergent skeletal muscle growth rates of broiler and layer chickens
<p>Abstract</p> <p>Background</p> <p>The genetic closeness and divergent muscle growth rates of broilers and layers make them great models for myogenesis study. In order to discover the molecular mechanisms determining the divergent muscle growth rates and muscle mass control in different chicken lines, we systematically identified differentially expressed genes between broiler and layer skeletal muscle cells during different developmental stages by microarray hybridization experiment.</p> <p>Results</p> <p>Taken together, 543 differentially expressed genes were identified between broilers and layers across different developmental stages. We found that differential regulation of slow-type muscle gene expression, satellite cell proliferation and differentiation, protein degradation rate and genes in some metabolic pathways could give great contributions to the divergent muscle growth rates of the two chicken lines. Interestingly, the expression profiles of a few differentially expressed genes were positively or negatively correlated with the growth rates of broilers and layers, indicating that those genes may function in regulating muscle growth during development.</p> <p>Conclusion</p> <p>The multiple muscle cell growth regulatory processes identified by our study implied that complicated molecular networks involved in the regulation of chicken muscle growth. These findings will not only offer genetic information for identifying candidate genes for chicken breeding, but also provide new clues for deciphering mechanisms underlining muscle development in vertebrates.</p
Case report: Cardiac arrest during carotid body tumor resection indicating carotid sinus hypersensitivity
BackgroundCarotid body tumor surgery is associated with various complications. However, intraoperative cardiac arrest is very rare and no more than 10 cases have been reported.Case descriptionA 58-year-old woman diagnosed with bilateral carotid body tumors underwent right carotid body tumor surgery. Sudden cardiac arrest occurred during the resection and was attributed to carotid sinus hypersensitivity. The patient recovered after prompt treatment and the tumor was removed completely with no complications.ConclusionCardiac arrest attributed to carotid sinus hypersensitivity during carotid body tumor resection is very rare. Proper treatments can reverse intraoperative cardiac arrest. If carotid sinus hypersensitivity is detected preoperatively, prophylactic temporary pacemaker implantation may be appropriate
Robust beam splitter with fast quantum state transfer through a topological interface
The Su-Schrieffer-Heeger (SSH) model, commonly used for robust state
transfers through topologically protected edge pumping, has been generalized
and exploited to engineer diverse functional quantum devices. Here, we propose
to realize a fast topological beam splitter based on a generalized SSH model by
accelerating the quantum state transfer (QST) process essentially limited by
adiabatic requirements. The scheme involves delicate orchestration of the
instantaneous energy spectrum through exponential modulation of nearest
neighbor coupling strengths and onsite energies, yielding a significantly
accelerated beam splitting process. Due to properties of topological pumping
and accelerated QST, the beam splitter exhibits strong robustness against
parameter disorders and losses of system. In addition, the model demonstrates
good scalability and can be extended to two-dimensional crossed-chain
structures to realize a topological router with variable numbers of output
ports. Our work provides practical prospects for fast and robust topological
QST in feasible quantum devices in large-scale quantum information processing.Comment: To be published in Frontiers of Physic
Altered microRNA expression in patients with non-obstructive azoospermia
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs), a class of small non-coding RNA molecules, are indicated to play essential roles in spermatogenesis. However, little is known about the expression patterns or function of miRNAs in human testes involved in infertility.</p> <p>Methods</p> <p>In this study, the miRNA expression profiles of testes of patients with non-obstructive azoospermia (NOA) and normal controls were performed by using microarray technologies.</p> <p>Results</p> <p>Altered microRNA expression in NOA patients was found, with 154 differentially down-regulated and 19 up-regulated miRNAs. These findings have been confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR) assays on select miRNAs, including miR-302a, miR-491-3p, miR-520d-3p and miR-383. Several down-regulated miRNA clusters in patients with NOA were identified, such as the oncogenic potential of the mir-17-92 cluster and mir-371,2,3 cluster.</p> <p>Conclusion</p> <p>This is the first report that the expression of miRNAs is altered in testicular tissues of patients with NOA, suggesting a role of miRNAs in regulating spermatogenesis in human males.</p
PO-046 Gene expression profiling of peripheral blood mononuclear cells in young male trampoline athletes
Objective Evidence indicates that physical activity influence bone health. However, the molecular mechanisms mediating the beneficial adaptations to exercise are not well understood. The purpose of this study was to examine the differentially expressed genes in PBMC between athletes and healthy controls, and to analyze the important functional genes and signal pathways that cause increased bone mineral density in athletes, in order to further reveal the molecular mechanisms of exercise promoting bone health.
Methods Five professional trampoline athletes and five age-matched untrained college students participated in this study. Used the human expression Microarray V4.0 expression profiling chip to detect differentially expressed genes in the two groups, and performed KEGG Pathway analysis and application of STRING database to construct protein interaction Network; Real-Time PCR technology was used to verify the expression of some differential genes.
Results Compared with healthy controls, there were significant improvement in lumbar spine bone mineral density, and 236 up-regulated as well as 265 down-regulated in serum samples of athletes. The differentially expressed genes involved 28 signal pathways, such as cell adhesion molecules. Protein interaction network showed that MYC was at the core node position. Real-time PCR results showed that the expression levels of CD40 and ITGα6 genes in the athletes were up-regulated compared with the healthy controls, the detection results were consistent with that of the gene chip.
Conclusions The findings highlight that long-term high-intensity trampoline training could induce transcriptional changes in PBMC of the athletes. These data suggest that gene expression fingerprints can serve as a powerful research tool to design novel strategies for monitoring exercise. The findings of the study also provide support for the notion that PBMC could be used as a substitute to study exercise training that affects bone health
Resistance to immune checkpoint inhibitors in advanced lung cancer: Clinical characteristics, potential prognostic factors and next strategy
BackgroundImmune checkpoint inhibitors (ICIs) have shown unprecedented clinical benefit in cancer immunotherapy and are rapidly transforming the practice of advanced lung cancer. However, resistance routinely develops in patients treated with ICIs. We conducted this retrospective study to provide an overview on clinical characteristics of ICI resistance, optimal treatment beyond disease progression after prior exposure to immunotherapy, as well as potential prognostic factors of such resistance.Methods190 patients diagnosed with unresectable lung cancer who received at least one administration of an anti-programmed cell death 1 (PD-1)/anti-programmed cell death-ligand 1(PD-L1) at any treatment line at Zhongshan Hospital Fudan University between Sep 2017 and December 2019 were enrolled in our study. Overall survival (OS) and progression-free survival (PFS) were analyzed. Levels of plasma cytokines were evaluated for the prognostic value of ICI resistance.ResultsWe found that EGFR/ALK/ROS1 mutation and receiving ICI treatment as second-line therapy were risk factors associated with ICI resistance. Patients with bone metastasis at baseline had a significantly shorter PFS1 time when receiving initial ICI treatment. Whether or not patients with oligo-progression received local treatment seemed to have no significant effect on PFS2 time. Systemic therapies including chemotherapy and anti-angiogenic therapy rather than continued immunotherapy beyond ICI resistance had significant effect on PFS2 time. TNF, IL-6 and IL-8 were significantly elevated when ICI resistance. Lower plasma TNF level and higher plasma IL-8 level seemed to be significantly associated with ICI resistance. A nomogram was established to prognosis the clinical outcome of patients treated with ICIs.ConclusionPatients with EGFR/ALK/ROS1 mutation, or those receiving ICI treatment as second-line therapy had higher risk of ICI resistance. Patients with bone metastasis had poor prognosis during immunotherapy. For those patients with oligo-progression after ICI resistance, combination with local treatment did not lead to a significantly longer PFS2 time. Chemotherapy and anti-angiogenic therapy rather than continued immunotherapy beyond ICI resistance had significant effect on PFS2 time. Levels of plasma cytokines including TNF, IL-6 and IL-8 were associated with ICI resistance
Physics perspectives of heavy-ion collisions at very high energy
Heavy-ion collisions at very high colliding energies are expected to produce
a quark-gluon plasma (QGP) at the highest temperature obtainable in a
laboratory setting. Experimental studies of these reactions can provide an
unprecedented range of information on properties of the QGP at high
temperatures. We report theoretical investigations of the physics perspectives
of heavy-ion collisions at a future high-energy collider. These include initial
parton production, collective expansion of the dense medium, jet quenching,
heavy-quark transport, dissociation and regeneration of quarkonia, photon and
dilepton production. We illustrate the potential of future experimental studies
of the initial particle production and formation of QGP at the highest
temperature to provide constraints on properties of strongly interaction
matter.Comment: 35 pages in Latex, 29 figure
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