Reduced D-Serine Release May Contribute to Impairment of Long-Term Potentiation by Corticosterone in the Perforant Path-Dentate Gyrus.

Long-term potentiation (LTP) is a neurobiological mechanism of cognitive function, and the N-methyl-D-aspartate (NMDA) receptors is fundamental for LTP. Previous studies showed that over activation of NMDA receptors may be a crucial cause of LTP and cognitive impairment induced by stress or corticosterone. However, other studies showed that the function of NMDA receptors is insufficient since the NMDA receptors co-agonist D-serine could improve stress-induced cognitive impairment. The purpose of this study is to clarify whether over activation of NMDA receptors or hypofunction of NMDA receptors is involved in hippocampal impairment of LTP by corticosterone and the underlying mechanisms. Results showed that hippocampal LTP and object location recognition memory were impaired in corticosterone-treated mice. Corticosterone increased the glutamate level in hippocampal tissues, neither NMDA receptors antagonist nor its subtype antagonists alleviated impairment of LTP, while enhancing the function of NMDA receptors by D-serine did alleviate impairment of LTP by corticosterone, suggesting that hypofunction of NMDA receptors might be one of the main reasons for impairment of LTP by corticosterone. Further results showed that the level of D-serine and its precursor L-serine did not change. D-serine release-related protein Na+-independent alanine-serine-cysteine transporter-1 (ASC-1) in the cell membrane was decreased and increasing D-serine release by the selective activator of ASC-1 antiporter activity alleviated impairment of LTP by corticosterone. Taken together, this study demonstrates that hypofunction of NMDA receptors may be involved in impairment of LTP by corticosterone and reduced D-serine release may be an important reason for its hypofunction, which is an important complement to existing mechanisms of corticosterone-induced LTP and cognitive impairment.

Phlegmadine A: A Lycopodium Alkaloid with a Unique Cyclobutane Ring from Phlegmariurus phlegmaria.

Phlegmadine A (1), a Lycopodium alkaloid with a unique cyclobutane ring and featuring a complex tetracyclo[4.2.2.03,8.03,10]decane-bridged system, together with three biogenetically related known compounds, was isolated from the Phlegmariurus phlegmaria. The structures and absolute configurations of 1 and 2 were determined by NMR and single-crystal X-ray analysis. Among them, compound 2 exhibited noticeable protective effects for long-term potentiation impairment by corticosterone induced in mice. Moreover, we succeeded in the efficient synthesis of 1 from 3 by a biomimetic synthesis method.

Diterpene ginkgolides protect against cerebral ischemia/reperfusion damage in rats by activating Nrf2 and CREB through PI3K/Akt signaling.

Diterpene ginkgolides meglumine injection (DGMI) is a therapeutic extract of Ginkgo biloba L, which has been used for the treatment of cerebral ischemic stroke in China. Ginkgolides A, B and C are the main components of DGMI. This study was designed to investigate the neuroprotective effects of DGMI components against ischemic stroke in vivo and in vitro. Acute cerebral ischemic injury was induced in rats by occlusion of the middle cerebral artery (MCA) for 1.5 h followed by 24 h reperfusion. The rats were treated with DGMI (1, 3 and 10 mg/kg, iv) at the onset of reperfusion and 12 h after reperfusion. Administration of DGMI significantly decreased rat neurological deficit scores, reduced brain infarct volume, and induced protein kinase B (Akt) phosphorylation, which prompted the nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and phosphorylation of the survival regulatory protein cyclic AMP-responsive element binding protein (CREB). Nrf2 activation led to expression of the downstream protein heme oxygenase-1 (HO-1). In addition, PC12 cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) in vitro, treatment with DGMI (1, 10 and 20 µg/mL) or ginkgolides A, B or C (10 µmol/L for each) significantly reduced PC12 cell death and increased phosphorylation of Akt, nuclear translocation of Nrf2 and activation of CREB. Activation of Nrf2 and CREB could be reversed by co-treatment with a phosphoinositide-3-kinase (PI3K) inhibitor LY294002. These observations suggest that ginkgolides act as novel extrinsic regulators activating both Akt/Nrf2 and Akt/CREB signaling pathways, protecting against cerebral ischemia/reperfusion (I/R) damage in vivo and in vitro.

[Salvianolic acid A alleviate the brain damage in rats after cerebral ischemia-reperfusion through Nrf2/HO-1 pathway].

The aim of present study is to investigate the protective effects and mechanism of salvianolic acid A (SAA) on cerebral ischemia-reperfusion injury in rats. The model was established with middle cerebral artery occlusion and reperfusion (MCAO/R) with ischemia for 1.5 h and reperfusion for 24 h in adult male SD rats. After the behavior assessment, TTC assay was used to calculate the infarct volume of rat brain; the distribution of Nrf2 in nuclear and cytoplasm and expression of HO-1 were detected by Western blot. The PC12 cells injury model was established with oxygen-glucose deprivation for 6 h and reintroduction for 24 h. Cell viability was determined with MTT assay, and the expression of Nrf2 and HO-1 were detected through immunofluorescence staining. The mechanisms were investigated in PC12 cells with Nrf2 knocking down by siRNA. SAA (10 and 20 mg·kg(-1)) significantly reduced the neuronal damage in MCAO/R model, and SAA(0.5 and 5 µmol·L(-1)) increased cell viability in PC12 cells injury model. Meanwhile, the nuclear translocation of Nrf-2 and the expression of HO-1 were increased in PC12 cell and rats brain. SAA exhibited anti-cerebral ischemia- reperfusion effects. The mechanism may be related to activation of Nrf2/HO-1 signaling pathway, which promotes the synthesis and nuclear translocation of Nrf2 to enhance the expression of the antioxidant protein HO-1.

Nodulisporiviridins A-H, Bioactive Viridins from Nodulisporium sp.

Eight new viridins, nodulisporiviridins A-H (1-8), were isolated from the extract of an endolichenic fungal strain Nodulisporium sp. (No. 65-17-2-1) that was fermented with potato-dextrose broth. The structures were determined using spectroscopic and X-ray crystallographic analysis. Nodulisporiviridins A-D (1-4) are unique viridins with an opened ring A. The Aß42 aggregation inhibitory activities of 1-8 were evaluated using a thioflavin T (ThT) assay with epigallocatechin gallate (EGCG) as the positive control (EGCG IC50 of 0.5 µM). Nodulisporiviridin G (7) displayed potent inhibitory activity with an IC50 value of 1.2 µM, and the preliminary trend of activity of these viridins as Aß42 aggregation inhibitors was proposed. The short-term memory assay on an Aß transgenic drosophila model of Alzheimer's disease showed that all eight compounds improved the short-term memory capacity, with potencies close to that of the positive control (memantine).

An integrated metabonomic and proteomic study on Kidney-Yin Deficiency Syndrome patients with diabetes mellitus in China.

AIM: To investigate specific changes in metabolites and proteins of Kidney-Yin Deficiency Syndrome (KYDS) patients with diabetes mellitus (DM) in China. METHODS: KYDS (n=29) and non-KYDS (n=23) patients with DM were recruited for this study. The KYDS was diagnosed by two senior TCM clinicians separately. The metabonomic and proteomic profiles of the patients were assessed using a metabonomic strategy based on NMR with multivariate analysis and a proteomic strategy based on MALDI-TOF-MS, respectively. RESULTS: Eighteen upregulated peptides and thirty downregulated peptides were observed in the plasma of the KYDS patients. Comparing the proteomic profiles of the KYDS and non-KYDS groups, however, no significantly differentially expressed peptides were found. At the same time, major metabolic alterations were found to distinguish the two groups, including eight significantly changed metabolites (creatinine, citrate, TMAO, phenylalanine, tyrosine, alanine, glycine and taurine). The levels of creatinine, citrate, TMAO, phenylalanine and tyrosine were decreased, whereas the levels of alanine, glycine and taurine were increased in the KYDS patients. These biochemical changes were found to be associated with alterations in amino acid metabolism, energy metabolism and gut microflora. CONCLUSION: The identification of distinct expression profiles of metabolites and signaling pathways in KYDS patients with DM suggests that there are indeed molecular signatures underlying the principles of 'Syndrome Differentiation' in traditional Chinese medicine.

Synthesis and biological evaluation of substituted 4-(thiophen-2-ylmethyl)-2H-phthalazin-1-ones as potent PARP-1 inhibitors.

We have developed a series of substituted 4-(thiophen-2-ylmethyl)-2H-phthalazin-1-ones as potent PARP-1 inhibitors. Preliminary biological evaluation indicated that most compounds possessed inhibitory potencies comparable to, or higher than AZD-2281. Among these compounds, 18q appeared to be the most notable one, which displayed an 8-fold improvement in enzymatic activity compared to AZD-2281. These efforts lay the foundation for our further investigation.

[Roles of adenosine receptors in Alzheimer's disease].

As an important neurotransmitter, adenosine displays its functions by acting on the adenosine receptors. Recent studies have shown that the distribution, expression and balance among subtypes of adenosine receptors are closely related with cognitive activities, and changes of adenosine receptors play key roles in neurodegenerative disorders including Alzheimer's disease. It has been pointed out that prolonged activation of adenosine receptors by high level adenosine may lead to the disturbance of balance among adenosine receptor subtypes. This imbalance mainly performed as increased expression of A2a receptor and decreased expression of A1 receptor, and enhancement of the excitatory signals mediated by A2a receptor and weakened inhibitory signals mediated by A1 receptor. Changes of these two subtypes of adenosine receptors may lead to a lot of disorders of neurological activities which developed into dysfunction of cognition to the end. These findings imply that the potential of maintaining the balance among adenosine receptors on the treatment of AD would facilitate both the revealing of the mechanism and the cure of AD.

[Effects of cornel iridoid glycoside on activity of cholinesterases in vitro].

The purpose of the present study was to investigate the effects of cornel iridoid glycoside (CIG) on the activity of cholinesterases in vitro, and to investigate the mechanism of CIG's treating Alzheimer's disease (AD). The sources of cholinesterases were prepared from human blood cells, rat brain homogenate and human blood plasma, respectively. The biochemical methods were used to detect the activity of acetylcholine esterase (AChE) and butyryl cholinesterase (BuChE) to investigate the influence of CIG on cholinesterases. The results showed that CIG inhibited the activity of AChE of human blood cells and rat brain homogenate, with the 50% inhibition rate (IC50) of 1.6 g . L-1 and 3.3 g . L-1, respectively; and the inhibition of AChE of CIG is reversible. CIG also inhibited the activity of BuChE of human blood plasma, with the IC50 of 2.9 g . L-1. In conclusion, CIG can inhibit the activity of AChE and BuChE in vitro, which may be one of the mechanisms of CIG to treat AD.

[Advance in studies on effect of paeoniflorin on nervous system].

Paeoniflorin (PF) is the chief active component of paeonia, with diverse pharmacological actions and wide application. Recently, the effect of PF on nervous system has attracted increasingly more attention. According to current study findings, PF can ameliorate the decline of memory and learning capacities in many dementia model animals, and have effect in protecting the cerebral ischemia injury, treating Parkinson's disease, reliving pain and improving neural synapse plasticity. Thought its mechanism has not been clarified, current findings show that adenosine A1 receptor plays an important role, while M cholinergic receptor, opiate receptor, calcium ion channel and NF-KB may also play a part in paeoniflorin's effect on nervous system.

Deletion of AhR attenuates fear memory leaving other types of memory intact.

The aryl hydrocarbon receptor (AhR), a classic "environmental sensor", has been found to play an important role in cognitive and emotional function. Recent studies showed AhR deletion led to an attenuated fear memory, providing a potential target against fear memory, whether it is the consequence of attenuated sense of fear or memory ability deficit or both is unclear. Here this study aims to work this out. The freezing time in contextual fear conditioning (CFC) reduced significantly in AhR knockout mice, indicating an attenuated fear memory. Hot plate test and acoustic startle reflex showed that AhR knockout did not change the pain threshold and hearing, excluded the possibility of sensory impairments. Results from NORT, MWM and SBT showed that deletion of AhR had little effects on other types of memory. But the anxiety-like behaviors reduced both in naïve or suffered (tested after CFC) AhR knockout mice, showing that AhR-deficient mice have a reduced basal and stressful emotional response. The basal low-frequency to high-frequency (LF/HF) ratio of the AhR knockout mice was significantly lower than that of the control group, indicating lower sympathetic excitability in the basal state, suggesting a low level of basal stress in the knockout mice. Before and after CFC, the LF/HF ratio of AhR-KO mice tended to be significantly lower than that of WT mice, and their heart rate was significantly lower; and the AhR-KO mice also has a decreased serum corticosterone level after CFC, suggesting a reduced stress response in AhR knockout mice. Altogether, the basal stress level and stress response were significant reduced in AhR knockout mice, which might contribute to the attenuated fear memory with little impairment on other types of memory, suggesting AhR as a "psychologic sensor" additional to "environmental sensor".

The green tea polyphenol (2)-epigallocatechin-3-gallate (EGCG) is not a ß-secretase inhibitor.

(2)-Epigallocatechin-3-gallate (EGCG) is a major polyphenolic component of green tea. A number of studies have demonstrated EGCG has the possibility for delaying the onset or retarding the progression of Alzheimer's disease (AD) and indicated EGCG possess inhibition of ß-secretase activity. We utilized homogeneous time-resolved fluorescence assay with a substrate Eu-CEVNLDAEFK-Qsy7 to screen ß-secretase inhibitor in a cell-free system and AlphaLISA assay in cell system. The results first showed that EGCG had significant inhibition of ß-secretase activity with IC(50) value of 7.57 × 10(-7)M in screening assay, but then we found EGCG had significant fluorescence-quenching effect in confirming assay, this indicates EGCG has the false positive ß-secretase inhibitory activity. Furthermore, the followed AlphaLISA assay based on cell showed EGCG did not reduce the ß-amyloid 1-40 secretion in HuAPPswe/HuBACE1 Chinese hamster ovary cell without affecting cell viability. Therefore our findings indicate EGCG do not inhibit ß-secretase cleavage activity. Overall this study illustrates that EGCG is not a ß-secretase inhibitor based on the compelling data. This provides further support that the choice of complementary assay format or technology is a critical factor in molecular screening and drug development for improving the hit-finding capability and efficiency.

[Visualization of right atrial flow patterns and quantification of pulmonary to systemic flow ratio in patients with atrial septal defect by vector flow mapping].

OBJECTIVE: To evaluate the ability of vector flow mapping (VFM) in visualizing right atrial flow and quantifying pulmonary to systemic flow ratio in patients with atrial septal defect (ASD). METHODS: VFM was performed on 30 patients with ASD and 50 healthy volunteers. The pulmonary to systemic flow ratio (Qp/Qs) was calculated using VFM and spectral doppler compared with that obtained through oximetric data derived from cardiac catheterization. RESULTS: Blood streams from superior and inferior caval veins did not collide but turned forward, contributing to a forward clockwise vortex during systole on the subcostal bi-atrial plane in the healthy volunteers. The vortex was disrupted continuously by a left to right shunt in the patients with ASD during the hole cardiac cycle. The Qp/Qs measured by VFM was less angle-dependent in all the cases than the other methods. The mean value of Qp/Qs of the healthy volunteers calculated by apical three-chamber view and apical five-chamber view ranged from 0.84:1 to 1.15:1, which is consistent with the theoretical value 1 of no left to right shunts. The values of Qp/Qs of patients with ASD measured by VFM and spectral doppler showed no significant differences with those obtained through oximetric data [(2.18 +/- 0.48) vs. (2.29 +/- 0.76), P = 0.29; (2.30 +/- 0.91) vs. (2.29 +/- 0.76), P = 0.86]. However, the Qp/Qs value measured by VFM had a better correlation with the oximetric data than that measured by spectral doppler (r = 0.71, P < 0.001 vs. r = 0.38, P < 0.05). The inter-observer and intraobserver variability of Qp/Qs measured by VFM was 9.84% and 9.86% respectively. CONCLUSION: VFM can visualize right atrial flow field in patients with ASD and quantify Qp/Qs in a more accurate way than spectral dopler.

[Treatment of post stroke cognitive impairment by rTMS].

Repetitive transcranial of magnetic stimulation (rTMS), as a new electrophysiological technique, has been used in treating neurological and psychiatric diseases in clinical. In recent years, rTMS has also been employed to explore the treatment options for post stroke cognitive impairment (PSCI). Studies showed that rTMS was beneficial to recovery of post-stroke aphasia, improvement of memory dysfunction and alleviation of hemispatial neglect. Moreover, it is safe for patient within the recommended parameters of safety guidance. rTMS exerts therapeutic effects by interfering with the reconstruction of cortical network, improving the cerebral blood flow and metabolism, adjusting the ion balance by modulating cortical excitability. In addition, rTMS could enhance synaptic plasticity, inhibit the apoptosis, and regulate the transmission of a variety of neurotransmitters. It was reviewed that the basic principles of rTMS, the efficacy, safety and mechanism of rTMS in the treatment of PSCI, as well as the current problems and prospects in this paper.

Stachyose Alleviates Corticosterone-Induced Long-Term Potentiation Impairment via the Gut-Brain Axis.

Stress can induce learning and memory impairment; corticosterone is often used to study the effects and mechanisms of stress in animal models. Long-term potentiation (LTP) has been widely used for tackling the mechanisms of memory. Liuwei Dihuang decoction-active fraction combination (LW-AFC) can improve stress-induced LTP and cognition impairment; stachyose is an oligosaccharide in LW-AFC. The effects and mechanisms of stachyose on stress are unknown. In this study, stachyose showed protective effects against LTP impairment by corticosterone in vivo only via intragastric administration for 7 consecutive days, but there was little effect even after direct intracerebroventricular injection; the protective effect of stachyose could be canceled by non-absorbable antibiotics (ATB) which disturbed gut flora. 16S rRNA sequencing, alpha diversity, and principal coordinate analysis (PCoA) revealed that the gut flora in corticosterone-treated mice was disturbed and stachyose could improve corticosterone-induced gut flora disturbance. Bacteroidetes were decreased and Deferribacteres were increased significantly in corticosterone-treated mice, and stachyose restored Bacteroidetes and Deferribacteres to the normal level. D-serine, a coactivator of NMDA receptors, plays an important role in synaptic plasticity and cognition. Here, corticosterone had little effect on the content of D-serine and L-serine (the precursor of D-serine), but it reduced the D-serine release-related proteins, Na+-independent alanine-serine-cysteine transporter-1 (ASC-1), and vesicle-associated membrane protein 2 (VAMP2) significantly in hippocampus; stachyose significantly increased ASC-1 and VAMP2 in corticosterone-treated mice, and ATB blocked stachyose's effects on ASC-1 and VAMP2. NMDA receptors co-agonists L-serine, D-serine, and glycine significantly improved LTP impairment by corticosterone. These results indicated that stachyose might indirectly increase D-serine release through the gut-brain axis to improve LTP impairment by corticosterone in the hippocampus in vivo.

Isorhynchophylline ameliorates stress-induced emotional disorder and cognitive impairment with modulation of NMDA receptors.

Introduction: Isorhynchophylline is one of the main active ingredients from Uncaria rhynchophylla, the effects and mechanisms of isorhynchophylline on stress-induced emotional disorders and cognitive impairment remain unclear. Methods: Long-term potentiation (LTP) in vivo was used for synaptic plasticity evaluation; chronic unpredictable mild stress (CUMS) model was used to evaluate the effect of isorhynchophylline on stress induced emotional disorders and cognitive impairment; sucrose preference test (SPT), open field test (OFT), and elevated plus maze (EPM) were used to evaluate emotional disorders; morris water maze (MWM) test was used to evaluate cognitive impairment; Western blotting (WB) was used to the expression of proteins; high performance liquid chromatography (HPLC) was used to quantify neurotransmitters; Nissl staining was used to identify pathological changes induced by stress. Results: In this study, we found that isorhynchophylline improved corticosterone-induced in vivo LTP impairment significantly, indicating positive effects on stress. Therefore, 28-day CUMS model was adopted to evaluate the anti-stress effects of isorhynchophylline. The results showed that isorhynchophylline improved CUMS-induced weight loss, anxiety- and depression-like behaviors, and spatial memory impairment. Isorhynchophylline reduced CUMS-induced corticosterone elevation. N-methyl-D-aspartic acid (NMDA) receptors play an important role in the process of emotion and memory. Glutamate and the expression of GluN2B increased in the CUMS mice, while D-serine and the expression of serine racemase (SR) decreased significantly, and isorhynchophylline restored these changes to normal level. Conclusion: These results indicated that isorhynchophylline ameliorated stress-induced emotional disorders and cognitive impairment, modulating NMDA receptors might be one of the underlying mechanisms.

Patients With Bicuspid Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

Objective: We sought to conduct a systematic review and meta-analysis of clinical adverse events in patients undergoing transcatheter aortic valve replacement (TAVR) with bicuspid aortic valve (BAV) vs. tricuspid aortic valve (TAV) anatomy and the efficacy of balloon-expandable (BE) vs. self-expanding (SE) valves in the BAV population. Comparisons aforementioned will be made stratified into early- and new-generation devices. Differences of prosthetic geometry on CT between patients with BAV and TAV were presented. In addition, BAV morphological presentations in included studies were summarized. Method: Observational studies and a randomized controlled trial of patients with BAV undergoing TAVR were included according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Results: A total of 43 studies were included in the final analysis. In patients undergoing TAVR, type 1 BAV was the most common phenotype and type 2 BAV accounted for the least. Significant higher risks of conversion to surgical aortic valve replacement (SAVR), the need of a second valve, a moderate or severe paravalvular leakage (PVL), device failure, acute kidney injury (AKI), and stroke were observed in patients with BAV than in patients with TAV during hospitalization. BAV had a higher risk of new permanent pacemaker implantation (PPI) both at hospitalization and a 30-day follow-up. Risk of 1-year mortality was significantly lower in patients with BAV than that with TAV [odds ratio (OR) = 0.85, 95% CI 0.75-0.97, p = 0.01]. BE transcatheter heart valves (THVs) had higher risks of annular rupture but a lower risk of the need of a second valve and a new PPI than SE THVs. Moreover, BE THV was less expanded and more elliptical in BAV than in TAV. In general, the rates of clinical adverse events were lower in new-generation THVs than in early-generation THVs in both BAV and TAV. Conclusions: Despite higher risks of conversion to SAVR, the need of a second valve, moderate or severe PVL, device failure, AKI, stroke, and new PPI, TAVR seems to be a viable option for selected patients with severe bicuspid aortic stenosis (AS), which demonstrated a potential benefit of 1-year survival, especially among lower surgical risk population using new-generation devices. Larger randomized studies are needed to guide patient selection and verified the durable performance of THVs in the BAV population.

Sex Difference in Outcomes Following Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis.

BACKGROUND: It is unknown whether the sex difference whereby female transcatheter aortic valve replacement (TAVR) candidates had a lower risk profile, a higher incidence of in-hospital complications, but more favorable short- and long-term survival observed in tricuspid cohorts undergoing TAVR would persist in patients with bicuspid aortic valves (BAVs). OBJECTIVES: The aim of this study was to reexamine the impact of sex on outcomes following TAVR in patients with BAVs. METHODS: In this single-center study, patients with BAVs undergoing TAVR for severe aortic stenosis from 2012 to 2021 were retrospectively included. Baseline characteristics, aortic root anatomy, and in-hospital and 1-year valve hemodynamic status and survival were compared between sexes. RESULTS: A total of 510 patients with BAVs were included. At baseline, women presented with fewer comorbidities. Men had a greater proportion of Sievers type 1 BAV, higher calcium volumes (549.2 ± 408.4 mm3 vs 920.8 ± 654.3 mm3; P < 0.001), and larger aortic root structures. Women experienced more vascular complications (12.9% vs 4.9%; P = 0.002) and bleeding (11.1% vs 5.3%; P = 0.019) and higher residual gradients (16.9 ± 7.7 mm Hg vs 13.2 ± 6.4 mm Hg; P < 0.001), while men were more likely to undergo second valve implantations during index TAVR (6.3% vs 15.9%; P = 0.001). Death at 1 year was not significantly different between sexes (HR: 1.15; 95% CI: 0.56-2.35; P = 0.70). Bleeding (adjusted HR: 4.62; 95% CI: 1.51-14.12; P = 0.007) was the single independent predictor of 1-year death for women. CONCLUSIONS: In patients with BAVs undergoing TAVR, women presented with fewer comorbidities, while men had a greater proportion of type 1 BAV, more calcification, and larger aortic roots. In-hospital outcomes favored men, with fewer complications except for the need for second valve implantation, but 1-year survival was comparable between sexes.

Expression of VGLUTs contributes to degeneration and acquisition of learning and memory.

Vesicular glutamate transporters (VGLUTs), which include VGLUT1, VGLUT2 and VGLUT3, are responsible for the uploading of L-glutamate into synaptic vesicles. The expression pattern of VGLUTs determines the level of synaptic vesicle filling (i.e., glutamate quantal size) and directly influences glutamate receptors and glutamatergic synaptic transmission; thus, VGLUTs may play a key role in learning and memory in the central nervous system. To determine whether VGLUTs contribute to the degeneration or acquisition of learning and memory, we used an animal model for the age-related impairment of learning and memory, senescence-accelerated mouse/prone 8 (SAMP8). KM mice were divided into groups based on their learning and memory performance in a shuttle-box test. The expression of VGLUTs and synaptophysin (Syp) mRNA and protein in the cerebral cortex and hippocampus were investigated with real-time fluorescence quantitative PCR and western blot, respectively. Our results demonstrate that, in the cerebral cortex, protein expression of VGLUT1, VGLUT2, VGLUT3 and Syp was decreased in SAMP8 with age and increased in KM mice, which displayed an enhanced capacity for learning and memory. The protein expression of VGLUT2 and Syp was decreased in the hippocampus of SAMP8 with aging. The expression level of VGLUT1 and VGLUT2 proteins were highest in KM mouse group with a 76-100% avoidance score in the shuttle-box test. These data demonstrate that protein expression of VGLUT1, VGLUT2 and Syp decreases age-dependently in SAMP8 and increases in a learning- and memory-dependent manner in KM mice. Correlation analysis indicated the protein expression of VGLUT1, VGLUT2 and Syp has a positive correlation with the capacity of learning and memory.