Glycogen Synthase Kinase-3β,NLRP3 Inflammasome,and Alzheimer's Disease

Alzheimer’s disease (AD) is the most prevalent cause of dementia worldwide. Because of the progressive neurodegeneration, individual cognitive and behavioral functions are impaired, affecting the quality of life of millions of people. Although the exact pathogenesis of AD has not been fully elucidated, amyloid plaques, neurofibrillary tangles (NFTs), and sustaining neuroinflammation dominate its characteristics. As one of the major tau kinases leading to hyperphosphorylation and aggregation of tau, glycogen synthase kinase-3β (GSK-3β) has been drawing great attention in various AD studies. Another research focus of AD in recent years is the inflammasome, a multiprotein complex acting as a regulator in immunological reactions to exogenous and endogenous danger signals, of which the Nod-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome has been studied mostly in AD and proven to play a significant role in AD development by its activation and downstream effects such as caspase-1 maturation and interleukin (IL)-1β release. Studies have shown that the NLRP3 inflammasome is activated in a GSK-3β-dependent way and that inhibition of the NLRP3 inflammasome downregulates GSK-3β, suggesting that these two important proteins are closely related. This article reviews the respective roles of GSK-3β and the NLRP3 inflammasome in AD as well as their relationship and interaction.

Cornel iridoid glycoside induces autophagy to protect against tau oligomer neurotoxicity induced by activation of glycogen synthase kinase-3β

Tau oligomers are the etiologic molecules of Alzheimer disease(AD), and correlate strongly with neuronal loss and exhibit neurotoxicity. Recent evidence indicates that small tau oligomers are the most relevant toxic aggregate species. The aim of the present study was to investigate the mechanisms of cornel iridoid glycoside(CIG) on tau oligomers and cognitive functions. We injected wortmannin and GF-109203 X(WM/GFX, 200 μmol·L-1 each) into the lateral ventricles to induce tau oligomer and memory impairment in rats. When oral y administered with CIG at 60 and 120 mg·kg-1 per day for 14 d, CIG decreased the escape latency in Morris water maze test. We also found that CIG restored the expression of presynaptic p-synapsin, synaptophysin, and postsynaptic density-95(PSD-95) decreased by WM/GFX in rat cortex. CIG reduced the accumulation of tau oligomers in the brain of WM/GFX rats and in cells transfected with wild type glycogen synthase kinase-3β(wt GSK-3β). In addition, CIG up-regulated the levels of ATG7, ATG12, Beclin-1, and LC3 II in vivo and in vitro, suggesting the restoration of autophagy function. These results suggest that CIG could ameliorate memory deficits and regulate memory-associated synaptic proteins through the clearance of tau oligomers accumulation. Moreover, CIG clears tau oligomers by restoring autophagy function.

The Akt/glycogen synthase kinase-3β pathway participates in the neuroprotective effect of interleukin-4 against cerebral ischemia/reperfusion injury

Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also called protein kinase B, PKB)/glycogen synthase kinase-3β(Akt/GSK-3β) signaling pathway is involved in oxidative stress, the inflammatory response, apoptosis, and autophagy. However, it is not yet clear whether the Akt/GSK-3β pathway participates in the neuroprotective effect of IL-4 against cerebral ischemia/reperfusion injury. In the present study, we established a cerebral ischemia/reperfusion mouse model by middle cerebral artery occlusion for 60 minutes followed by a 24-hour reperfusion. An IL-4/anti-IL-4 complex(10 μg) was intraperitoneally administered 30 minutes before surgery. We found that administration of IL-4 significantly alleviated the neurological deficits, oxidative stress, cell apoptosis, and autophagy and reduced infarct volume of the mice with cerebral ischemia/reperfusion injury 24 hours after reperfusion. Simultaneously, IL-4 activated Akt/GSK-3β signaling pathway. However, an Akt inhibitor LY294002, which was injected at 15 nmol/kg via the tail vein, attenuated the protective effects of IL-4. These findings indicate that IL-4 has a protective effect on cerebral ischemia/reperfusion injury by mitigating oxidative stress, reducing apoptosis, and inhibiting excessive autophagy, and that this mechanism may be related to activation of the Akt/GSK-3β pathway. This animal study was approved by the Animal Ethics Committee of Renmin Hospital of Wuhan University, China(approval No. WDRY2017-K037) on March 9, 2017.

Mismatched effects of receptor interacting protein kinase-3 on hepatic steatosis and inflammation in nonalcoholic fatty liver disease

AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.

电项针对全脑缺血VD模型大鼠PI3K/AKT/GSK-3β信号通路的影响

目的研究电项针对全脑缺血血管性痴呆(vascular dementia,VD)模型大鼠磷脂酰肌醇-3-激酶/丝氨酸-苏氨酸蛋白激酶/糖原合成酶激酶-3β(Phosphatidylinositol-3 kinase/serine-threonine kinase/glycogen synthase kinase-3β,P13K/AKT/GSK-3β)信号通路的影响。方法采用四血管阻断方法制备VD模型大鼠,电项针组取双侧风池穴、供血穴,电针30 min/次,1次/d,治疗14d。采用Y迷宫评价大鼠学习记忆能力;荧光定量PCR(RT-PCR)、Western blot法检测大鼠海马组织中磷酸化蛋白激酶B(phosphorylatedproteinkinaseB,p-AKT)、磷酸化糖原合成酶激酶-3β(Phosphorylated GSK-3β,P-GSK-3β)mRNA和p-AKT、p-GSK-3β蛋白的表达。结果与模型组比较,电项针组可显著提高VD大鼠Y迷宫学习与记忆正确次数(P<0.01)。与模型组比较,电项针组大鼠海马组织中p-AKT、p-GSK-3βmRNA和p-AKT、p-GSK-3β蛋白表达均有不同程度的升高(P<0.01)。结论电项针能够改善VD模型大鼠学习记忆能力,具体机制可能是激活PI3K/AKT/GSK-3β信号通路,发挥抗凋亡作用,起到对缺血海马神经元的保护作用。

PGK1-coupled HSP90 stabilizes GSK3βexpression to regulate the stemness of breast cancer stem cells

Objective:Glycogen synthase kinase-3β(GSK3β)has been recognized as a suppressor of Wnt/β-catenin signaling,which is critical for the stemness maintenance of breast cancer stem cells.However,the regulatory mechanisms of GSK3βprotein expression remain elusive.Methods:Co-immunoprecipitation and mass spectral assays were performed to identify molecules binding to GSK3β,and to characterize the interactions of GSK3β,heat shock protein 90(Hsp90),and co-chaperones.The role of PGK1 in Hsp90 chaperoning GSK3βwas evaluated by constructing 293T cells stably expressing different domains/mutants of Hsp90α,and by performing a series of binding assays with bacterially purified proteins and clinical specimens.The influences of Hsp90 inhibitors on breast cancer stem cell stemness were investigated by Western blot and mammosphere formation assays.Results:We showed that GSK3βwas a client protein of Hsp90.Hsp90,which did not directly bind to GSK3β,interacted with phosphoglycerate kinase 1 via its C-terminal domain,thereby facilitating the binding of GSK3βto Hsp90.GSK3β-bound PGK1 interacted with Hsp90 in the“closed”conformation and stabilized GSK3βexpression in an Hsp90 activity-dependent manner.The Hsp90 inhibitor,17-AAG,rather than HDN-1,disrupted the interaction between Hsp90 and PGK1,and reduced GSK3βexpression,resulting in significantly reduced inhibition ofβ-catenin expression,to maintain the stemness of breast cancer stem cells.Conclusions:Our findings identified a novel regulatory mechanism of GSK3βexpression involving metabolic enzyme PGK1-coupled Hsp90,and highlighted the potential for more effective cancer treatment by selecting Hsp90 inhibitors that do not affect PGK1-regulated GSK3βexpression.

脂多糖预处理导致的糖原合成酶激酶-3抑制对肝糖原的影响和机制

目的探讨脂多糖预处理时糖原合成酶激酶3(glycogen synthase kinase-3,GSK-3)功能活性的变化及其对肝组织糖原代谢的影响和机制。方法雄性SD大鼠随机分为正常对照、脂多糖预处理和GSK-3抑制剂氯化锂预处理组,分别进行相应处理后再接受大剂量脂多糖(10 mg/kg)攻击以建立脂多糖诱导的急性肝损伤模型;采用PAS染色法观察肝组织糖原聚集,用试剂盒法定量检测肝组织糖原含量,以Western Blot法半定量分析GSK-3的蛋白表达和抑制性磷酸化水平,采用考马斯亮兰比色法测定肝组织钙依赖蛋白酶的活性。结果尽管大剂量脂多糖攻击后各组动物肝组织糖原含量组间比较均无显著差异(P>0.05),但均较攻击前有显著降低(P<0.05),且脂多糖和氯化锂预处理均可导致肝组织糖原含量增加(P<0.05);尽管诱导脂多糖预处理并未改变GSK-3的蛋白表达水平(P>0.05),但导致GSK-3β抑制性磷酸化(P<0.05)和GSK-3α不完全裂解;大剂量脂多糖攻击后肝组织钙依赖蛋白酶活性较前显著升高(P<0.05),但组间比较无显著差异(P>0.05)。结论脂多糖预处理导致GSK-3β抑制性磷酸化和GSK-3α不完全裂解,促进肝组织糖原合成和聚集,但不影响钙依赖蛋白酶活性,有利于增加肝组织糖原储备并可能在遭受大剂量脂多糖攻击时提供能量需求。

Chinese Prescription Kangen-karyu as Potential Anti-Alzheimer’s Disease Therapeutic:Analyses of BACE1 and GSK-3βInhibitory Activities

Inhibition ofβ-site amyloid precursor protein-cleaving enzyme 1(BACE1)or glycogen synthase kinase-3β(GSK-3β)is estimated to be the central therapeutic approach for Alzheimer’s disease(AD).In this study,water extract of Kangenkaryu,its crude drug and chemical composition used in oriental medicine were evaluated regarding their BACE1 and GSK-3βinhibitory activities.Fluorescence resonance energy transfer was used to characterize the BACE1 inhibitory effect of Kangen-karyu,its crude drug and chemical composition.GSK-3βactivity was determined using the Kinase-Glo Luminescent Kinase Assay Platform.The water extract of Kangen-karyu inhibited BACE1 and GSK-3βin concentration-dependent manners when compared with reference drugs,quercetin and luteolin.Among six components of Kangen-karyu,the water extracts of Salviae Miltiorrhizae Radix or Cyperi Rhizoma exhibited significant inhibitory effects on BACE1 and GSK-3β.Among the constituents of Salviae Miltiorrhizae Radix extract,salvianolic acid C,salvianolic acid A,rosmarinic acid,and magnesium lithospermate B significantly inhibited BACE1.In addition,they inhibited GSK-3βwith an IC50 value range of 6.97 to 135.35μM.From these results,one of the effectiveness and its mechanisms of action of Kangen-karyu against AD may be the inhibition of BACE1 and GSK-3β,and one of the active ingredients of Kangen-karyu is Salviae Miltiorrhizae Radix and its constituents.

Sevoflurane plays a reduced role in cognitive impairment compared with isoflurane: limited effect on fear memory retention

Isoflurane and sevoflurane are both inhalation anesthetics,but in clinical application,sevoflurane has been considered to be less suitable for long-term anesthesia because of its catabolic compounds and potential nephrotoxicity.Nevertheless,recent studies have shown that these two inhalation anesthetics are similar in hepatorenal toxicity,cost,and long-term anesthetic effect.Moreover,sevoflurane possibly has less cognitive impact on young mice.In this study,C57BL/6 mice aged 8–10 weeks were exposed to 1.2%isoflurane or 2.4%sevoflurane for 6 hours.Cognitive function and memory were examined in young mice using the novel object recognition,contextual fear conditioning,and cued-fear extinction tests.Western blot assay was performed to detect expression levels of D1 dopamine receptor,catechol-O-methyltransferase,phospho-glycogen synthase kinase-3β,and total glycogen synthase kinase-3βin the hippocampus.Our results show that impaired performance was not detected in mice exposed to sevoflurane during the novel object recognition test.Contextual memory impairment in the fear conditioning test was shorter in the sevoflurane group than the isoflurane group.Long-term sevoflurane exposure did not affect memory consolidation,while isoflurane led to memory consolidation and reduced retention.Downregulation of hippocampal D1 dopamine receptors and phosphorylated glycogen synthase kinase-3β/total glycogen synthase kinase-3βand upregulation of catechol-O-methyltransferase may be associated with differing memory performance after exposure to isoflurane or sevoflurane.These results confirm that sevoflurane has less effect on cognitive impairment than isoflurane,which may be related to expression of D1 dopamine receptors and catechol-O-methyltransferase and phosphorylation of glycogen synthase kinase-3βin the hippocampus.This study was approved by the Institutional Animal Care and Use Committee,Nanjing University,China on November 20,2017(approval No.20171102).

Combined treatment with valproic acid and estrogen has neuroprotective effects in ovariectomized mice with Alzheimer’s disease

Postmenopausal women with Alzheimer’s disease exhibit dramatically reduced sensitivity to estrogen replacement therapy,which is though to be related to an estrogen receptor(ER)α/ERβratio imbalance arising from a significantly decreased level of ERs of the brain.The aim of our study was to investigate whether valproic acid(VPA)can enhance the beneficial effects of estrogen on cognitive function through restoration of ERαand ERβexpression in the brain.We removed the ovaries of female APP/PS1 mice to simulate the low estrogen levels present in postmenopausal women and then administered VPA(30 mg/kg,intraperitoneal injection,once daily),17β-estradiol(E2)(2.4μg,intraperitoneal injection,once daily),liquiritigenin(LG)(50μg/kg,intragastric infusion,once daily),VPA+E2,or VPA+LG for 4 successive weeks.Compared with treatment with a single drug,treatment with VPA+E2 or VPA+LG significantly increased the level of glycogen synthase kinase 3β,increased the expression of estrogen receptorα,reduced the expression of small ubiquitin-like modifiers,and increased the level of estrogen receptorβ.This resulted in enhanced sensitivity to estrogen therapy,reduced amyloidβaggregation,reduced abnormal phosphorylation of the tau protein,reduced neuronal loss,increased dendritic spine and postsynaptic density,and significantly alleviated memory loss and learning impairment in Alzheimer’s disease.This study was approved by the Chongqing Medical University Animal Protection and Ethics Committee,China on March 6,2013.

Chemokine ligand 20 enhances progression of hepatocellular carcinoma via epithelial-mesenchymal transition

AIM: To identify the mechanisms of chemokine ligand 20(CCL20)-induced hepatocellular carcinoma(HCC) metastasis and evaluate it as a prognostic marker. METHODS: Expression of CCL20 was evaluated by immunohistochemistry in HCC tissues from 62 patients who underwent curative resection. The relationship between CCL20 expression and clinicopathologic features was analyzed. Univariate and multivariate analyses were performed to evaluate its predictive value for recurrence and survival of HCC patients. The expression levels ofepithelial-mesenchymal transition(EMT)-and signaling pathway-related proteins were evaluated by Western blotting and immunocytochemistry. The effects of CCL20 on HCC cell proliferation and migration were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenoltetrazolium bromide(MTT) and Transwell assays. RESULTS: CCL20 immunoreactivity was detected in all 62 patient specimens. CCL20 expression was associated with preoperative alpha-fetoprotein level(P = 0.043), tumor size(P = 0.000), tumor number(P = 0.008), vascular invasion(P = 0.014), and tumor differentiation(P = 0.007). Patients with high CCL20 expression had poorer recurrence-free and overall survivals compared to those with low CCL20 expression(both P < 0.001). CCL20 induced EMT-like changes in HCC cells and increased their proliferation and migration ability(P < 0.05). Western blotting and immunofluorescence staining showed that CCL20 induced an EMT-like phenotype in HCC cells, and increased expression of phosphorylated AKT, β-catenin and vimentin, and decreased E-cadherin expression(P < 0.05). The correlation analysis revealed that high CCL20 expression in HCC tissue specimens was negatively correlated with E-cadherin expression(13.33%, 4/30), and positively correlated with vimentin(90.0%, 27/30), β-catenin(96.67%, 29/30) and p-AKT(76.67%, 23/30) expression.CONCLUSION: CCL20 expression is associated with HCC recurrence and patient survival and promotes HCC cell proliferation and migration by inducing EMT-like changes via PI3K/AKT and Wnt/β-catenin pathways.

Plasma levels of receptor interacting protein kinase-3 correlated with coronary artery disease

Background: Necroptosis plays an important role in human atherosclerosis and atheroma development. Since receptor interacting protein kinase-3 (RIP3) acts as a key mediator of necroptosis, this study aimed to explore its relationship between plasma RIP3 levels and coronary artery disease (CAD) and discover a potential new biomarker for screening CAD subtypes and severity. Methods: A total of 318 patients with CAD who had coronary angiography and 166 controls in Peking Union Medical College Hospital from September 2017 to January 2018 were enrolled in this study. Patients with CAD were divided into three subgroups: patients with stable coronary artery disease (SCAD), patients with unstable angina (UA), and patients with myocardial infarction (MI). The severity of atherosclerosis was determined by Gensini score (GSS). Logistic regression was used to determine the relationship between plasma RIP3 levels and CAD. The correlation between plasma RIP3 and GSS was calculated using multiple linear regression models. Results: Overall, plasma RIP3 levels were significantly higher than serum RIP3 levels. Plasma RIP3 levels in patients with CAD were significantly higher than those in controls. Plasma RIP3 levels were strongly associated with CAD (odds ratio: 6.00, 95% confidence interval 3.04–11.81;P < 0.001). Plasma RIP3 levels increased linearly from controls to patients with SCAD, then patients with UA, and finally to patients with MI. We found a significantly positive correlation between proportion of cases of acute coronary syndrome in subjects and their plasma RIP3 level quartile. Plasma RIP3 levels were also associated with GSS (B 0.027;standard error 0.012;P < 0.05). Conclusions: Plasma RIP3 levels were independently associated with CAD. Plasma RIP3 levels could potentially supplement clinical assessment to screen CAD and determine CAD severity.

Intranasal insulin ameliorates neurological impairment after intracerebral hemorrhage in mice

In Alzheimer’s disease and ischemic stroke,intranasal insulin can act as a neuroprotective agent.However,whether intranasal insulin has a neuroprotective effect in intracerebral hemorrhage and its potential mechanisms remain poorly understood.In this study,a mouse model of autologous blood-induced intracerebral hemorrhage was treated with 0.5,1,or 2 IU insulin via intranasal delivery,twice per day,until 24 or 72 hours after surgery.Compared with saline treatment,1 IU intranasal insulin treatment significantly reduced hematoma volume and brain edema after cerebral hemorrhage,decreased blood-brain barrier permeability and neuronal degeneration damage,reduced neurobehavioral deficits,and improved the survival rate of mice.Expression levels of p-AKT and p-GSK3βwere significantly increased in the perihematoma tissues after intranasal insulin therapy.Our findings suggest that intranasal insulin therapy can protect the neurological function of mice after intracerebral hemorrhage through the AKT/GSK3βsignaling pathway.The study was approved by the Ethics Committee of the North Sichuan Medical College of China(approval No.NSMC(A)2019(01))on January 7,2019.

Proteomics of the mediodorsal thalamic nucleus of rats with stress-induced gastric ulcer

BACKGROUND Stress-induced gastric ulcer(SGU) is one of the most common visceral complications after trauma. Restraint water-immersion stress(RWIS) can cause serious gastrointestinal dysfunction and has been widely used to study the pathogenesis of SGU to identify medications that can cure the disease. The mediodorsal thalamic nucleus(MD) is the centre integrating visceral and physical activity and contributes to SGU induced by RWIS. Hence, the role of the MD during RWIS needs to be studied.AIM To screen for differentially expressed proteins in the MD of the RWIS rats to further elucidate molecular mechanisms of SGU.METHODS Male Wistar rats were selected randomly and divided into two groups, namely, a control group and an RWIS group. Gastric mucosal lesions of the sacrificed rats were measured using the erosion index and the proteomic profiles of the MD were generated through isobaric tags for relative and absolute quantitation(iTRAQ) coupled with two-dimensional liquid chromatography and tandem mass spectrometry. Additionally, iTRAQ results were verified by Western blot analysis.RESULTS A total of 2853 proteins were identified, and these included 65 dysregulated(31 upregulated and 34 downregulated) proteins(fold change ratio ≥ 1.2). Gene Ontology(GO) analysis showed that most of the upregulated proteins are primarily related to cell division, whereas most of the downregulated proteins are related to neuron morphogenesis and neurotransmitter regulation. Ingenuity Pathway Analysis revealed that the dysregulated proteins are mainly involved in the neurological disease signalling pathways. Furthermore, our results indicated that glycogen synthase kinase-3 beta might be related to the central mechanismthrough which RWIS gives rise to SGU.CONCLUSION Quantitative proteomic analysis elucidated the molecular targets associated with the production of SGU and provides insights into the role of the MD. The underlying molecular mechanisms need to be further dissected.

Treadmill training improves neurological deficits and suppresses neuronal apoptosis in cerebral ischemic stroke rats

RehabilNation training is believed to be beneficial to patients with stroke, but its molecular mechanism is still unclear. Rat models of cerebral ischemic stroke were established by middle cerebral artery occlusion/reperfusion, and then received treadmill training of different intens让ies, twice a day for 30 minutes for 1 week. Low-intensity training was conducted at 5 m/min, with a 10-minute running, 10-minute rest, and 10-minute running cycle. In the moderate-intensity training, the intensity gradually increased from 5 m/min to 10 m/min in 5 minutes, with the same rest cycle as above. In high-intensity training, the intensity gradually increased from 5 m/min to 25 m/min in 5 minutes, with the same rest cycle as above. The Bederson scale was used to evaluate the improvement of motor function. Infarct volume was detected using 2,3,5-triphenyltetrazolium chloride staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining was applied to detect the apoptosis of nerve cells in brain tissue. Western blot assay was employed to analyze the activation of cyclic adenosine monophosphate (cAMP)/protein kinase A and Akt/glycogen synthase kinase-3卩 signaling pathways in rat brain tissue. All training intensities reduced the neurological deficit score, infarct volume, and apoptosis in nerve cells in brain tissue of stroke rats. Training intensities activated the cAMP/protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This activation was more obvious with higher training intensities. These changes were reversed by intracerebroventricular injection of protein kinase A inhibitor Rp-cAMP. Our findings indicate that the neuroprotective effect of rehabilitation training is achieved via activation of the cAMP/ protein kinase A and Akt/glycogen synthase kinase-3 beta signaling pathways. This study was approved by the Ethics Committee of Animal Experimentation in Shanghai No. 8 Peoples Hospital, China.

Platelet biomarkers in Alzheimer's disease

The search for diagnostic and prognostic markers in Alzheimer's disease(AD) has been an area of active research in the last decades. Biochemical markers are correlates of intracerebral changes that can be identified in biological fluids, namely: peripheral blood(total blood, red and white blood cells, platelets, plasma and serum), saliva, urine and cerebrospinal fluid. An important feature of a biomarker is that it can be measured objectively and evaluated as(1) an indicator of disease mechanisms(markers of core pathogenic processes or the expression of downstream effects of these processes), or(2) biochemical responses to pharmacological or therapeutic intervention, which can be indicative of disease modification. Platelets have been used in neuropharmacological models since the mid-fifties, as they share several homeostatic functions with neurons, such as accumulation and release of neurotransmitters, responsiveness to variations in calcium concentration, and expression of membrane-bound compounds. Recent studies have shown that platelets also express several components related to the pathogenesis of AD,in particular to the amyloid cascade and the regulation of oxidative stress: thus they can be used in the search for biomarkers of the disease process. For instance, platelets are the most important source of circulating forms of the amyloid precursor protein and other important proteins such as Tau and glycogen synthase kinase-3B. Moreover, platelets express enzymes involved in membrane homeostasis(e.g., phospholipase A2), and markers of the inflammatory process and oxidative stress. In this review we summarize the available literature and discuss evidence concerning the potential use of platelet markers in AD.

Regulation of Wnt/β-catenin signaling by herpesviruses

The Wnt/β-catenin signaling pathway is instrumental in successful differentiation and proliferation of mammalian cells. It is therefore not surprising that the herpesvirus family has developed mechanisms to interact with and manipulate this pathway. Successful coexistence with the host requires that herpesviruses establish a lifelong infection that includes periods of latency and reactivation or persistence. Many herpesviruses establish latency in progenitor cells and viral reactivation is linked to host-cell proliferation and differentiation status. Importantly, Wnt/β-catenin is tightly connected to stem/progenitor cell maintenance and differentiation. Numerous studies have linked Wnt/β-catenin signaling to a variety of cancers, emphasizing the importance of Wnt/β-catenin pathways in development, tissue homeostasis and disease. This review details how the alpha-, beta-, and gammaherpesviruses interact and manipulate the Wnt/β-catenin pathway to promote a virus-centric agenda.

Antiepileptic Drug-Induced Apoptosis Was Prevented by L-Type Calcium Channel Activator in Cultured Rat Cortical Cells

Experimental data have shown that antiepileptic drugs cause neurodegeneration in developing rats. Valproate (VPA) is the drug of choice in primary generalized epilepsies, and carbamazepine (CBZ) is one of the most prescribed drugs in partial seizures. These drugs block sodium channels, thereby reducing sustained repetitive neuronal firing. The intracellular mechanisms whereby AEDs induce neuronal cell death are unclear. We examined whether AEDs induce apoptotic cell death in cultured cortical cells and whether calcium ions are involved in the AED-induced cell death. VPA and CBZ increased apoptotic cell death and induced morphological changes that were characterized by cell shrinkage and nuclear condensation or fragmentation. Incubation of cortical cultures with VPA or CBZ decreased phospho-Akt levels. CBZ decreased the intracellular calcium levels. On the other hand, FPL64176, an L-type calcium channel activator, increased the intracellular calcium levels and prevented the AED-induced apoptosis. Glycogen synthase kinase-3 inhibitors, such as alsterpaullone and azakenpaullone, prevented the AED-induced apoptosis. These results suggest that intracellular calcium level changes are associated with AEDs and apoptosis and that the activation of glycogen synthase kinase-3 is involved in the death of rat cortical neurons.

黑逍遥散对AD模型小鼠海马区Aβ_(1-42),GSK-3β,NEP,IDE表达的影响

目的:研究黑逍遥散对阿尔茨海默症(Alzheimer disease,AD)小鼠海马区β淀粉样多肽1-42(β-amyloid 1-42peptide,Aβ1-42),糖原合成酶激酶-3(glycogen synthase kinase-3β,GSK-3β),脑啡肽酶(neprilysin,NEP),胰岛素抵抗酶(insulindegrading enzyme,IDE)表达的影响。方法:42只APP/PSI双转基因小鼠称体质量后,按随机原则分为4组,分别为模型组,阳性药组(盐酸多奈哌齐,3. 25 mg·kg-1),黑逍遥散高、低剂量组(6,3 g·kg-1)。10只同月龄、同种系的野生型C57BL/6J小鼠为正常组。连续灌胃12周后,Morris水迷宫予以行为学检测,苏木素-伊红(HE)染色观察海马神经元的形态改变,采用免疫组化技术分别检测小鼠海马区Aβ1-42,GSK-3β,NEP,IDE蛋白的表达。结果:治疗3个月后,与正常组比较,AD模型组小鼠,逃避潜伏期均延长,跨原平台次数减少(P <0. 01),小鼠海马区Aβ1-42,GSK-3β蛋白阳性表达显著增强,NEP与IDE蛋白阳性表达显著减弱(P <0. 01),HE染色显示AD模型小鼠海马神经细胞损伤严重;与模型组比较,用药各组小鼠的逃避潜伏期均显著缩短、跨原平台次数均显著增加(P <0. 05,P <0. 01),小鼠海马区Aβ1-42,GSK-3β蛋白阳性表达显著减弱,NEP与IDE蛋白阳性表达显著增强(P <0. 05,P <0. 01),HE染色显示各治疗组小鼠海马神经细胞损伤减轻。结论:黑逍遥散能够显著改善AD小鼠的学习记忆能力,可能与调节Aβ在海马区的异常沉积和降解作用等方面来减轻AD小鼠认知能力损伤有关。

Unilateral amyloid-β25-35 injection into the rat amygdala increases the expressions of aberrant tau phosphorylation kinases

背景 Neuropathologically， Alzheimer 疾病(广告) 被在淀粉的肽充实的细胞外的匾的存在描绘；然而，它由导致 neurotoxicity 的机制是学习是调查它是否将经由源于它的增加的 kinase 基因 expression.Methods 的异常 phosphorylated 字形物的改进推动 Alzheimer 疾病的进步的这的 uncertain.The 目的 24 只雄的老鼠被划分成三个组，并且每个组把 8 rats:control ，假冒操作，和 A25-35 注射广告模型 groups.AD 老鼠模型被 A25-35 的单方的注射创造进 amygdala.