Eukaryotes initiate autophagy to cope with the lack of external nutrients, which requires the activation of the nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase Sirtuin 1 (Sirt1). However, the mechanisms underlying the starvation-induced Sirt1 activation for autophagy initiation remain unclear. Here, we demonstrate that glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a conventional glycolytic enzyme, is a critical mediator of AMP-activated protein kinase (AMPK)-driven Sirt1 activation. Under glucose starvation, but not amino acid starvation, cytoplasmic GAPDH is phosphorylated on Ser122 by activated AMPK. This causes GAPDH to redistribute into the nucleus. Inside the nucleus, GAPDH interacts directly with Sirt1, displacing Sirt1's repressor and causing Sirt1 to become activated. Preventing this shift of GAPDH abolishes Sirt1 activation and autophagy, while enhancing it, through overexpression of nuclear-localized GAPDH, increases Sirt1 activation and autophagy. GAPDH is thus a pivotal and central regulator of autophagy under glucose deficiency, undergoing AMPK-dependent phosphorylation and nuclear translocation to activate Sirt1 deacetylase activity.
This study investigated the correlation of preoperative plasma fibrinogen level with distant metastasis and prognosis in esophageal squamous cell carcinoma (ESCC). A total of 255 patients with ESCC who underwent surgery in Zhejiang cancer hospital (Hangzhou, China), between October 2006 and December 2009, were evaluated in this retrospective study. Population controls were selected from a pool of cancer-free subjects in the same region. Each patient and cancer-free people provided 3-mL pretreatment blood. Plasma fibrinogen level was measured by the Clauss method. The effects of hyperfibrinogenemia on locoregional relapse-free survival (LRFS), distant metastasis-free survival (DMFS), relapse-free survival (RFS), and overall survival (OS) were assessed using Kaplan-Meier analysis. Independent prognostic factors were identified in the multivariate Cox analysis. The proportion of hyperfibrinogenemia was higher in ESCC patients than those in controls (40.4% vs 13.6%). Subjects with hyperfibrinogenemia had a significantly higher risk of ESCC than those with normal plasma fibrinogen level (adjust OR = 4.61; 95% CI = 3.02–7.01, P < 0.001) after adjusted for age, sex and smoking status. The Kaplan-Meier curves showed that patients with hyperfibrinogenemia had worse DMFS, RFS and OS (P < 0.001). Tumor length, lymph node metastasis and plasma fibrinogen level were independent prognostic factors of ESCC (P < 0.05). Increased plasma fibrinogen level was significantly associated with elevated risk of ESCC. Preoperative plasma fibrinogen level was a predictor of distant metastasis and independently associated with prognosis of patients with ESCC.
The purpose of the present study was to study the effects of resveratrol on cognitive function in rats with vascular dementia and to investigate the molecular mechanisms of its neuroprotective effects. Forty-five SD rats were randomly divided into 3 groups: The control group (Con group, n=15), the model group (VD group, n=15) and the resveratrol-treated VD group (Res group, n=15). The VD rats (the VD group and the Res group) were generated by bilateral common carotid artery occlusion. The rats in the Res group received daily resveratrol treatment intraperitoneally for 4 weeks. Cognitive function was tested using the Morris water maze test. The levels of SOD and MDA (oxidative stress indicators) were detected by ELISA kits. The protein expression of Bax, Bcl-2 and caspase-3 was detected by western blotting. Compared with the rats in the Con group, the rats in the VD group exhibited decreased cognitive function, significantly increased hippocampal content of MDA, Bax and caspase-3 (P<0.05), and significantly reduced hippocampal expression of SOD and Bcl-2 (P<0.05). Compared with the rats in the VD group, the rats in the Res group exhibited increased cognitive ability, reduced hippocampal content of MDA, Bax and caspase-3 (P<0.05), and increased hippocampal expression of SOD and Bcl-2 (P<0.05). Resveratrol treatment significantly improved the spatial learning and memory of the VD rats. The mechanism associated with the neuroprotective effects of resveratrol may be closely related to the inhibition of the apoptosis pathway and oxidative stress injury.
Background: The use of PCI in early operable patients with small cell lung cancer (SCLC) is still controversial. Therefore, we conducted a systematic review with meta-analysis to investigate the effects of PCI in resected SCLC patients.Methods: Relevant studies were identified from PubMed and EMBASE databases, the pooled hazard risks were obtained by the random-effects model. We also analyzed the brain metastasis (BM) risk in p-stage I patients without PCI.Results: Five retrospective studies were identified and a total of 1691 patients were included in our analysis, 315 of them received PCI. For all the resected patients, PCI was associated with improved overall survival (HR: 0.52, 95% CI: 0.33-0.82), and reduced brain metastasis risk (RR: 0.50, 95%CI: 0.32-0.78). However, with regard to p-stage I patients, no survival benefit was brought by PCI (HR: 0.87, 95% CI: 0.34-2.24). Moreover, the pooled analysis of 7 studies found that the 5-year brain metastasis risk was relatively low (12%, 95% CI: 8%-17%) for p-stage I patients without PCI.Conclusions: PCI might be associated with a favorable survival advantage and reduced BM risk in complete resected SCLC patients, except for p-stage I patients.
In order to evaluate the possibility of using Cr³⁺ co-doping to modify the emission properties of Pr³⁺-based quantum cutting phosphors, which emit one ultraviolet (UV) and one visible photon from each vacuum-UV photon absorbed, into phosphors that emit two visible photons, the optical spectroscopies between 150 and 750 nm of CaAl₁₂O₁₉:M³⁺ (M = Pr,Cr) were investigated and compared with those of SrAl₁₂O₁₉:M³⁺ using synchrotron radiation as one of the excitation sources. When Pr³⁺ is excited to its 4f5d states, cascade emission of UV photons from the ¹S₀ state followed by visible photons from the ³P₀ state are both observed in (Ca,Sr)Al₁₂O₁₉:Pr³⁺. Similar to SrAl₁₂O₁₉:M³⁺, there exist desirable spectral overlaps between Pr³⁺ ¹S₀ emissions and the Cr³⁺ higher multiplet absorptions in CaAl₁₂O₁₉, which should be favourable to the energy transfer from Pr³⁺ ¹S₀ to Cr³⁺, converting the UV photon from Pr³⁺ ¹S₀ into the red Cr³⁺ emission. However, the host absorption band and the Cr³⁺-related charge transfer band have an unfavourable overlap with the Pr³⁺ 4f5d states in the vacuum-UV region, preventing efficient selective Pr³⁺ excitation under radiation of Xe discharge, a prerequisite for the quantum cutting process.
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