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The objective of this study was to investigate the neuroprotective and antioxidant effects of ginsenoside compound K (CK) in a model of scopolamine hydrobromide-induced, memory-impaired mice. The role of CK in the regulation of amyloid β (Aβ) and its capacity to activate the Nrf2/Keap1 signaling pathway were also studied due to their translational relevance to Alzheimer’s disease. The Morris water maze was used to assess spatial memory functions. Levels of superoxide dismutase, glutathione peroxidase, and malondialdehyde in brain tissues were tested. Cell morphology was detected by hematoxylin and eosin staining and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay. Immunohistochemistry and western blotting were used to determine expression levels of Nrf2/Keap1 signaling pathway-related factors and Aβ. Ginsenoside CK was found to enhance memory function, normalize neuronal morphology, decrease neuronal apoptosis, increase superoxide dismutase and glutathione peroxidase levels, reduce malondialdehyde levels, inhibit Aβ expression, and activate the Nrf2/Keap1 signaling pathway in scopolamine-exposed animals. Based on these results, we conclude that CK may improve memory function in scopolamine-injured mice by regulating Aβ aggregation and promoting the transduction of the Nrf2/Keap1 signaling pathway, thereby reducing oxidative damage to neurons and inhibiting neuronal apoptosis. This study suggests that CK may serve as a future preventative agent or treatment for Alzheimer’s disease.

RNA arbitrarily primed PCR (RAP-PCR) was used to isolate cDNAs that represent developmentally regulated brain-specific genes. Five clones with a restricted pattern of expression were identified and sequenced. Four cDNAs had no obvious homology to the sequences in GenBank. One clone had over 95% homology to a Ca2+/calmodulin-insensitive adenylyl cyclase, a recently cloned gene that was isolated from rat brain and was shown to be expressed only in adult brain and lung. Two novel cDNAs were investigated further by Northern blot analysis and were found to be expressed differentially during development; their expression was confined to the forebrain in the adult mouse. Further characterization byin situ hybridization showed that the mRNA corresponding to one clone was localized to a limited number of differentiating functional structures in the developing nervous system. In the adult brain, this message is confined to the forebrain with the highest level of expression in the cortex. These data suggest that the product of this gene is involved in the establishment of neuronal networks during brain development and in synaptic plasticity in the mature cortex. This work demonstrates that RAP-PCR is a powerful method for the simultaneous detection of differences between multiple RNA populations and, as such, can be used to study differential gene expression in the brain.

Pirh2, a p53-induced ubiquitin-protein ligase, has been reported to promote ubiquitin-dependent degradation of p27kip1, which plays an essential role in mammalian cell cycle regulation and neurogenesis in the developing central nervous system (CNS). However, their distributions and functions in the nervous system lesion and repair remain unclear. In this study, we observed that the up-regulated expression of Pirh2 was concomitant with decreased p27kip1 level after traumatic brain injury by Western blot and immunohistochemistry. Immunofluorescence double-labeling revealed that Pirh2 was mainly co-expressed with GFAP and CD11b. Meanwhile, we also examined the expression profiles of proliferating cell nuclear antigen (PCNA) whose changes were correlated with the expression of Pirh2. In addition, Pirh2 colocalized with p27kip1 and PCNA. Immunoprecipitation further showed that they interacted with each other in the pathophysiology process. In summary, our data indicated Pirh2 might be a negative regulator of p27kip1 and associated with glial proliferation.

We used a chemical genomics approach that includes follow up in parallel syntheses to discover a new class of compounds that selectively suppress glial activation. While the mechanism of action remains to be determined, available data and the experimental approach for discovery indicate that the mechanism includes inhibition of gene regulating protein kinases. Specifically, the increased production of IL-1β and iNOS in response to various activating stimuli, including Aβ1-42, is suppressed while the production of potentially beneficial responses, such as ApoE production, is not inhibited. The increased production of COX-2 and p38 MAPK activation are also not altered, demonstrating the novel nature of potential therapeutic targets compared to currently available drugs. The chemical scaffold is 3-aminopyridazine (3-AP). This is an attractive scaffold because of its potential for diversification by established, facile chemistries and the prior use of a 3-AP scaffold in other central nervous system targeted therapeutics. Therefore, the potential bioavailability of 3-AP derivatives and the demonstrated cellular selectivity demand that future research address the potential efficacy of selective 3-AP derivatives in animal models of disease.

Alley running has been successfully used as an operant to demonstrate both the positive and negative reinforcing effect of intravenously administered drugs of abuse in a bona fide operant conditioning paradigm, the Ettenberg runway, in which confounding drug effects on motor performance and drug accumulation are avoided. While Ettenberg and colleagues focus on the intravenous route of drug administration, we tested the practicability of the subcutaneous route of administration in this runway paradigm in Sprague Dawley rats, using morphine as the investigated drug of abuse. We also modified the Ettenberg runway, most notably in that either food (sweetened condensed milk), no food, morphine, or saline was presented outside the runway in a separate cage. This made shaping, i.e., the initial presentation of a food reinforcer within the runway, necessary to establish responding. The manipulations necessary to administer subcutaneous (sc) injections were well tolerated by over 90% of the tested rats (n=93). However, sc injections increased runtimes to the experimenter cutoff of 60 s within 20 once-daily sessions. Because of strong experimenter effects, all morphine doses or saline had to be administered blind. Under these experimenter-blind conditions, 0.1 and 1 mg/kg subcutaneous morphine proved to be reinforcing in that these doses significantly slowed down the gradual increase in runtimes imposed upon by the sc injection procedure. Thus, morphine can be demonstrated to be a positive reinforcer in a modified Ettenberg runway even when given subcutaneously. This effect, however, is eventually overcome by the negative reinforcing effect of subjecting the animals to sc injection procedure.

Cerebral infarct is a common disease of older adults, which could increase the risk for cognitive impairment and dementia. Electroencephalogram (EEG) characteristics were analyzed to investigate the applied value in the assessment of cognitive impairment of the cerebral infarct patients. One hundred ten subjects with cerebral infarcts (including 65 cases of cognitive impairment patients (CI-CI) and 45 cases of cognitive normality patients (CI-NC)) and 110 normal health persons (NC) were recruited between July 2009 and March 2011 at the Department of Neurology. All of the patients were analyzed by EEG within 1 day they were hospitalized. The EEG analysis results were compared with the Montreal Cognitive Assessment (MoCA) scale (assessed within 2 weeks) with the methods of correlation analysis, clustering analysis, and concordance analysis. The results indicated that CI-CI patients had significantly lower EEG beta power (0.832 ± 0.203 mcV2) relative to the CI-NC group (1.493 ± 0.271 mcV2, P < 0.01) or NC group (1.565 ± 0.345 mcV2, P < 0.01). Significant negative correlation between the beta power and infarct size (as well as infarct number) was discovered (r = −0.88881 and −0.66498, respectively, both P < 0.001). There was a good concordance between K-means clustering algorithm calculating the beta power and MoCA scoring (Kappa = 0.851, P < 0.001). The preliminary findings suggest that the recognition techniques of EEG hold considerable promise for the assessment of cognitive impairment post cerebral infarcts within 2 weeks and which related to the size of infarcts and number of infarcts.

Methylene blue (MB) has a protective effect on cognitive decline caused by chronic hypoperfusion, but the specific mechanism is not clear. This article aims to determine whether MB protects vascular neurons through PI3K/Akt and plays a role in improving cognitive impairment. Molecular biological methods, the hippocampal neuronal density test, the hippocampal vascular network density test, and dynamic enhanced magnetic resonance imaging (MRI) were used to detect the blood–brain barrier permeability and Evans blue leakage rate in the hippocampus. We also observed and evaluated the changes in the above results after administration of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway protein inhibitor LY294002. There were significant differences for cerebral blood flow (CBF) between the chronic cerebral hypoperfusion (CCH) + MB group (100 ml/100 g/min) and the CCH group (60 ml/100 g/min, P < 0.05). After using LY294002, the CBF of the CCH + MB + LY294002 group dropped to 82 ml/100 g/min. The vascular density in the CCH + MB group was 23%, which is significantly higher than that in the CCH group (15.1%) (P < 0.05). The vascular density (17.5%) in the CCH + MB + LY294002 group was significantly higher than that in the CCH group but lower than that in the CCH + MB group. Western blotting results showed that one week after intraperitoneal injection of MB, the expression of t-Akt and p-Akt in the CCH + MB group was increased after CCH, and LY294002 partially blocked this up-regulation effect (CCH + MB + LY294002 group). MB is a potential therapy for the relief of mild cognitive impairment associated with CCH, vascular dementia, and Alzheimer’s disease.

Although oxidative stress has been implicated in the pathogenesis of numerous neurodegenerative conditions, the precise mechanisms by which reactive oxygen species (ROS) induce neuronal death are still being explored. The generation of reactive lipid peroxidation products is thought to contribute to ROS neurotoxicity. Isoprostanes (IsoPs), prostaglandin-like molecules formed in vivo via the ROS-mediated oxidation of arachidonic acid, have been previously demonstrated to be formed in increased amounts in the brains of patients with various neurodegenerative diseases. Recently, we have identified a new class of IsoPs, known as A2- and J2-IsoPs or cyclopentenone IsoPs, which are highly reactive electrophiles and form adducts with thiol-containing molecules, including cysteine residues in proteins and glutathione. Cyclopentenone IsoPs are favored products of the IsoP pathway in the brain and are formed abundantly after oxidant injury. These compounds also potently induce neuronal apoptosis by a mechanism which involves glutathione depletion, ROS generation, and activation of several redox-sensitive pathways that overlap with those involved in other forms of oxidative neurodegeneration. Cyclopentenone IsoPs also enhance neurodegeneration caused by other insults at biologically relevant concentrations. These data are reviewed, whereas new data demonstrating the neurotoxicity of J-ring IsoPs and a discussion of the possible role of cyclopentenone IsoPs as contributors to neurodegeneration are presented.

Ischemic stroke is considered to be a complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors. MicroRNAs participated in various physiopathological processes; common single-nucleotide polymorphisms (SNPs) in pre-miRNAs have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of the hsa-mir-196-a2/rs11614913 T/C, hsa-mir-146a/rs2910164 C/G, and hsa-mir-499/rs3746444 A/G polymorphisms in pre-miRNAs with the risk of ischemic stroke in a Chinese population. The three polymorphisms were identified in 296 ischemic stroke patients and 391 healthy controls using polymerase chain reaction–restriction fragment length polymorphism. The frequency of the allele G of hsa-mir-499/rs3746444 A/G showed significant association with ischemic stroke when compared with controls (OR = 1.509, 95%CI = 1.151–1.978, P = 0.003). Increased ischemic stroke risks were associated with rs3746444 A/G genotypes in different genetic model (homozygote comparison: P = 0.045, OR = 2.084, 95%CI = 1.019–4.262; heterozygote comparison: P = 0.024, OR = 1.489, 95%CI = 1.063–2.087; dominant genetic model: P = 0.007, OR = 1.563, 95%CI = 1.135–2.153). Similar results were obtained by adjusted fully risk factors. However, we failed to find any association between the alleles and genotypes of rs2910164 C/G and rs11614913 T/C SNPs and ischemic stroke, respectively (p > 0.05). The present study provided evidence that hsa-mir-499/rs3746444 A/G polymorphism might be associated with a significantly increased risk of ischemic stroke in a Chinese population, indicating that the common genetic polymorphism in pre-microRNAs contributed to the pathogenesis of ischemic stroke.