Olfactory Dysfunction and Alzheimer's Disease: A Review.

 Alzheimer's disease is the most common cause of dementia, and it is one of the leading causes of death globally. Identification and validation of biomarkers that herald the onset and progression of Alzheimer's disease is of paramount importance for early reliable diagnosis and effective pharmacological therapy commencement. A substantial body of evidence has emerged demonstrating that olfactory dysfunction is a preclinical symptom of neurodegenerative diseases including Alzheimer's disease. While a correlation between olfactory dysfunction and Alzheimer's disease onset and progression in humans exists, the mechanism underlying this relationship remains unknown. The aim of this article is to review the current state of knowledge regarding the range of potential factors that may contribute to the development of Alzheimer's disease-related olfactory dysfunction. This review predominantly focuses on genetic mutations associated with Alzheimer's disease including amyloid-ß protein precursor, presenilin 1 and 2, and apolipoprotein E mutations, that may (in varying ways) drive the cellular events that lead to and sustain olfactory dysfunction.

Efficacy of Sailuotong on neurovascular unit in amyloid precursor protein/presenilin-1 transgenic mice with Alzheimer's disease.

OBJECTIVE: To discuss the influence of Sailuotong (, SLT) on the Neurovascular Unit (NVUs) of amyloid precursor protein (APP)/presenilin-1(PS1) mice and evaluate the role of gas supplementation in activating blood circulation during the progression of Alzheimer's disease (AD). METHODS: The mice were allocated into the following nine groups: (a) the C57 Black (C57BL) sham-operated group (control group), (b) ischaemic treatment in C57BL mice (the C57 ischaemic group), (c) the APP/PS1 sham surgery group (APP/PS1 model group), (d) ischaemic treatment in APP/PS1 mice (APP/PS1 ischaemic group), (e) C57BL mice treated with aspirin following ischaemic treatment (C57BL ischaemic + aspirin group), (f) C57BL mice treated with SLT following ischaemic treatment (C57BL ischaemic + SLT group), (g) APP/PS1 mice treated with SLT (APP/PS1 + SLT group), (h) APP/PS1 mice treated with donepezil hydrochloride following ischaemic treatment (APP/PS1 ischaemic + donepezil hydrochloride group) and (i) APP/PS1 mice treated with SLT following ischaemic treatment (APP/PS1 ischaemic + SLT group). The ischaemic model was established by operating on the bilateral common carotid arteries and creating a microembolism. The Morris water maze and step-down tests were used to detect the spatial behaviour and memory ability of mice. The hippocampus of each mouse was observed by haematoxylin and eosin (HE) and Congo red staining. The ultrastructure of NVUs in each group was observed by electron microscopy, and various biochemical indicators were detected by enzyme-linked immunosorbent assay (ELISA). The protein expression level was detected by Western blot. The mRNA expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: The results of the Morris water maze and step-down tests showed that ischemia reduced learning and memory in the mice, which were restored by SLT. The results of HE staining showed that SLT restored the pathological changes of the NVUs. The Congo red staining results revealed that SLT also improved the scattered orange-red sediments in the upper cortex and hippocampus of the APP/PS1 and APP/PS1 ischaemic mice. Furthermore, SLT significantly reduced the content of Aß, improved the vascular endothelium and repaired the mitochondrial structures. The ELISA detection, western blot detection and qRT-PCR showed that SLT significantly increased the vascular endothelial growth factor (VEGF), angiopoietin and basic fibroblast growth factor, as well as the levels of gene and protein expression of low-density lipoprotein receptor-related protein-1 (LRP-1) and VEGF in brain tissue. CONCLUSIONS: By increasing the expression of VEGF, SLT can promote vascular proliferation, up-regulate the expression of LRP-1, promote the clearance of Aß and improve the cognitive impairment of APP/PS1 mice. These results confirm that SLT can improve AD by promoting vascular proliferation and Aß clearance to protect the function of NVUs.

γ-Secretase Inhibitors Selected by Molecular Docking, to Develop a New Drug Against Alzheimer's Disease.

Background: Alzheimer´s disease (AD) is one of the most common forms of dementia, is characterized by memory loss and cognitive impairment that affects more than 30 million people worldwide. The pathogenesis of Alzheimer's disease is primary driven by brain accumulation of the amyloid ß peptide generated from the amyloid-ß precursor protein (APP) via cleavages by ß- and γ-secretase. In this study, we propose an approach by molecular docking to select compounds as γ-secretase inhibitors for decreasing the APP generation. Methods: We selected potential γ-secretase inhibitors by molecular docking in the potential site between Asp257, Lue268, Asp385, Ile387, Phe388, and Leu432 amino acids in presenilin-1 (PS-1), using a chemical library of over 500,000 compounds. Results: Eight compounds (AZ1 - AZ8) were selected by molecular docking to develop γ-secretase inhibitors for decreasing the APP generation. Conclusions: AZ1 - AZ8 compounds could be interacting in the potential site between Asp257, Lue268, Asp385, Ile387, Phe388, and Leu432 amino acids in PS-1. These compounds could specifically interact in the binding pocket in PS-1 to prevent/decrease the APP generation, to develop a new drug against Alzheimer's disease.

BACE1 Overexpression Reduces SH-SY5Y Cell Viability Through a Mechanism Distinct from Amyloid-ß Peptide Accumulation: Beta Prime-Mediated Competitive Depletion of sAßPPα.

BACKGROUND: The Alzheimer's disease (AD)-associated amyloid-beta protein precursor (AßPP) can be cleaved by ß-site AßPP cleaving enzyme 1 (BACE1) and the γ-secretase complex to yield neurotoxic amyloid-ß (Aß) peptides. However, AßPP can also be cleaved in a 'non-amyloidogenic' manner either by α-secretase to produce soluble AßPP alpha (sAßPPα) (a fragment with neuroprotective/neurogenic functions) or through alternative BACE1-mediated 'beta prime' activity yielding soluble AßPP beta prime (sAßPPß'). OBJECTIVE: To determine whether sAßPPα depletion, as opposed to Aß peptide accumulation, contributes to cytotoxicity in AD-relevant SH-SY5Y neuroblastoma cell models. METHODS: AßPP proteolysis was characterized by immunoblotting in mock-, wild-type AßPP (wtAßPP)-, BACE1-, and Swedish mutant AßPP (SweAßPP)-transfected cells. AßPP beta prime cleavage was confirmed through secretase inhibitor studies and C-terminal fragment analysis. The roles of sAßPPα and sAßPPß' in cell viability were confirmed by overexpression studies. RESULTS: Despite producing enhanced Aß peptide levels, wtAßPP- and SweAßPP-transfected cells did not exhibit reduced viability whereas BACE1-transfected cells did. sAßPPα generation in SH-SY5Y-BACE1 cells was virtually ablated in lieu of BACE1-mediated sAßPPß' production. sAßPPα overexpression in SH-SY5Y-BACE1 cells restored viability whereas sAßPPß' overexpression decreased viability further. The anti-AßPP 6E10 antibody was shown to cross-react with sAßPPß'. CONCLUSION: sAßPPα depletion and/or sAßPPß' accumulation, but not elevated Aß peptide levels, represent the cytotoxic mechanism following BACE1 overexpression in SH-SY5Y cells. These data support the novel concept that competitive sAßPPα depletion by BACE1 beta prime activity might contribute to AD. The cross-reactivity of 6E10 with AßPPß'also questions whether previous studies assessing sAßPPα as a biomarker using this antibody should be revisited.

Mitochondrial Membrane Potential Influences Amyloid-ß Protein Precursor Localization and Amyloid-ß Secretion.

BACKGROUND: Amyloid-ß (Aß), which derives from the amyloid-ß protein precursor (AßPP), forms plaques and serves as a fluid biomarker in Alzheimer's disease (AD). How Aß forms from AßPP is known, but questions relating to AßPP and Aß biology remain unanswered. AD patients show mitochondrial dysfunction, and an Aß/AßPP mitochondria relationship exists. OBJECTIVE: We considered how mitochondrial biology may impact AßPP and Aß biology. METHODS: SH-SY5Y cells were transfected with AßPP constructs. After treatment with FCCP (uncoupler), Oligomycin (ATP synthase inhibitor), or starvation Aß levels were measured. ß-secretase (BACE1) expression was measured. Mitochondrial localized full-length AßPP was also measured. All parameters listed were measured in ρ0 cells on an SH-SY5Y background. iPSC derived neurons were also used to verify key results. RESULTS: We showed that mitochondrial depolarization routes AßPP to, while hyperpolarization routes AßPP away from, the organelle. Mitochondrial AßPP and cell Aß secretion inversely correlate, as cells with more mitochondrial AßPP secrete less Aß, and cells with less mitochondrial AßPP secrete more Aß. An inverse relationship between secreted/extracellular Aß and intracellular Aß was observed. CONCLUSION: Our findings indicate mitochondrial function alters AßPP localization and suggest enhanced mitochondrial activity promotes Aß secretion while depressed mitochondrial activity minimizes Aß secretion. Our data complement other studies that indicate a mitochondrial, AßPP, and Aß nexus, and could help explain why cerebrospinal fluid Aß is lower in those with AD. Our data further suggest Aß secretion could serve as a biomarker of cell or tissue mitochondrial function.

Sorting Out the Role of the Sortilin-Related Receptor 1 in Alzheimer's Disease.

Sortilin-related receptor 1 (SORL1) encodes a large, multi-domain containing, membrane-bound receptor involved in endosomal sorting of proteins between the trans-Golgi network, endosomes and the plasma membrane. It is genetically associated with Alzheimer's disease (AD), the most common form of dementia. SORL1 is a unique gene in AD, as it appears to show strong associations with the common, late-onset, sporadic form of AD and the rare, early-onset familial form of AD. Here, we review the genetics of SORL1 in AD and discuss potential roles it could play in AD pathogenesis.

Generation of Transgenic Cynomolgus Monkeys Overexpressing the Gene for Amyloid-ß Precursor Protein.

Alzheimer's disease (AD) is the most common cause of dementia and understanding its pathogenesis should lead to improved therapeutic and diagnostic methods. Although several groups have developed transgenic mouse models overexpressing the human amyloid-ß precursor protein (APP) gene with AD mutations, with and without presenilin mutations, as well as APP gene knock-in mouse models, these animals display amyloid pathology but do not show neurofibrillary tangles or neuronal loss. This presumably is due to differences between the etiology of the aged-related human disease and the mouse models. Here we report the generation of two transgenic cynomolgus monkeys overexpressing the human gene for APP with Swedish, Artic, and Iberian mutations, and demonstrated expression of gene tagged green fluorescent protein marker in the placenta, amnion, hair follicles, and peripheral blood. We believe that these nonhuman primate models will be very useful to study the pathogenesis of dementia and AD. However, generated Tg monkeys still have some limitations. We employed the CAG promoter, which will promote gene expression in a non-tissue specific manner. Moreover, we used transgenic models but not knock-in models. Thus, the inserted transgene destroys endogenous gene(s) and may affect the phenotype(s). Nevertheless, it will be of great interest to determine whether these Tg monkeys will develop tauopathy and neurodegeneration similar to human AD.

Role of Cdk5 in Amyloid-beta Pathology of Alzheimer's Disease.

Alzheimer's Disease (AD) is a progressive neurodegenerative disease with irreversible cognitive impairment. So far, successful treatment and prevention for this disease are deficient in spite of delaying the progression of cognitive impairment and dementia. Cyclin dependent kinase 5 (Cdk5), a unique member of the cyclin-dependent kinase family, is involved in AD pathogenesis and may be a pathophysiological mediator that links the major pathological features of AD. Cdk5 dysregulation interferes with the proteolytic processing of Amyloid-beta Protein Precursor (APP) and modulates amyloidbeta (Aß) by affecting three enzymes called α-, ß- and γ-secretase, which are critical for the hydrolysis of APP. Given that the accumulation and deposition of Aß derived from APP are a common hinge point in the numerous pathogenic hypotheses of AD, figuring out that influence of specific mechanisms of Cdk5 on Aß pathology will deepen our understanding of AD.

Fragile X and APP: a Decade in Review, a Vision for the Future.

Fragile X syndrome (FXS) is a devastating developmental disability that has profound effects on cognition, behavior, and seizure susceptibility. There are currently no treatments that target the underlying cause of the disorder, and recent clinical trials have been unsuccessful. In 2007, seminal work demonstrated that amyloid-beta protein precursor (APP) is dysregulated in Fmr1KO mice through a metabotropic glutamate receptor 5 (mGluR5)-dependent pathway. These findings raise the hypotheses that: (1) APP and/or APP metabolites are potential therapeutic targets as well as biomarkers for FXS and (2) mGluR5 inhibitors may be beneficial in the treatment of Alzheimer's disease. Herein, advances in the field over the past decade that have reproduced and greatly expanded upon these original findings are reviewed, and required experimentation to validate APP metabolites as potential disease biomarkers as well as therapeutic targets for FXS are discussed.

Tau Pathology of Alzheimer Disease: Possible Role of Sleep Deprivation.

Sleep deprivation is a common complaint in modern societies. Insufficient sleep has increased the risk of catching neurodegenerative diseases such as Alzheimer's. Several studies have indicated that restricted sleep increases the level of deposition of ß-amyloid and formation of neurofibrillary tangles, the major brain microstructural hallmarks for Alzheimer disease. The mechanisms by which sleep deprivation affects the pathology of Alzheimer disease has not yet been fully and definitively identified. However, risk factors like apolipoprotein E risk alleles, kinases and phosphatases dysregulation, reactive oxygen species, endoplasmic reticulum damages, glymphatic system dysfunctions and orexinergic system inefficacy have been identified as the most important factors which mediates between the two conditions. In this review, these factors are briefly discussed.

Effect of soluble amyloid precursor protein α on nerve cell apoptosis and neurological function in subarachnoid hemorrhage rats / 中华老年心脑血管病杂志

Objective To study the effect of soluble amyloid precursor protein α (sAPPα) on nerve cell apoptosis and neurological function in subarachnoid hemorrhage (SAH) rats.Methods Sixty male SD rats were randomly divided into control group (n=20),SAH+saline group (n=20) and SAH+sAPPα group (n=20).A SAH model was established by injecting autologous blood into cistern magna in rats.After a SAH model was established for SAH + saline group and SAH + sAPPα group by injecting saline and sAPPα respectively into the cistern magna of rats,the apoptotic cells were detected by immunofluorescene with TUNEL staining and the neurological function was scored in 10 rats from each group on day 3 after injection of sAPPα and saline.Results The number of apoptotic cells in brain tissue was significantly greater in SAH+saline group than in control group (P＜0.05) and was significantly smaller in SAH+sAPPα group than in SAH+ saline group (P＜0.05).The neurological function score was 26.7±0.5,13.9±0.7 and 23.0±0.8 respectively in control group,SAH + saline group and SAH + sAPPα group.Conclusion sAPPα alleviates secondary damage of neurological function by inhibiting the apoptosis of nerve cells in rats after SAH and can thus improve their neurological function.

Cyclic cis-Locked Phospho-Dipeptides Reduce Entry of AßPP into Amyloidogenic Processing Pathway.

The cis/trans isomerization of X-Pro peptide bonds in proteins in some instances acts as a molecular switch in biological pathways. Our prior work suggests that the cis isomer of the phospho-Thr668-Pro669 motif, located in the cytoplasmic domain of the amyloid-ß protein precursor (AßPP), is correlated with an increase in amyloidogenic processing of AßPP and production of amyloid-beta (Aß), the neurotoxic peptide fragment in Alzheimer's disease (AD). We designed a 100% cis-locked cyclic dipeptide composed of cyclized phospho-Thr-Pro (pCDP) as a mimic for this putative pathological conformation, and three phosphate-blocked derivatives (pCDP-diBzl, pCDP-Bzl, and pCDP-diPOM). Two H4 neuroglioma cell lines were established as AD cell models for use in testing these compounds: H4-AßPP695 for stable overexpression of wild-type AßPP695, and H4-BACE1 for stable overexpression of ß-site AßPP cleaving enzyme-1 (BACE1). The level of the secreted AßPP fragment resulting from BACE1 activity, sAßPPß, served as a key proxy for amyloidogenic processing, since cleavage of AßPP by BACE1 is a requisite first step in Aß production. Of the compounds tested, pCDP-diBzl decreased sAßPPß levels in both cell lines, while pCDP-diPOM decreased sAßPPß levels in only H4-BACE1 cells, all with similar dose-dependences and patterns of proteolytic AßPP fragments. Enzymatic assays showed that none of the pCDP derivatives directly inhibit BACE1 catalytic activity. These results suggest a model in which pCDP-diBzl and pCDP-diPOM act at a common point to inhibit entry of AßPP into the amyloidogenic AßPP processing pathway but through different targets, and provide important insights for the development of novel AD therapeutics.

Reduction of Blood Amyloid-ß Oligomers in Alzheimer's Disease Transgenic Mice by c-Abl Kinase Inhibition.

One of the pathological hallmarks of Alzheimer's disease (AD) is the presence of amyloid plaques, which are deposits of misfolded and aggregated amyloid-beta peptide (Aß). The role of the c-Abl tyrosine kinase in Aß-mediated neurodegeneration has been previously reported. Here, we investigated the therapeutic potential of inhibiting c-Abl using imatinib. We developed a novel method, based on a technique used to detect prions (PMCA), to measure minute amounts of misfolded-Aß in the blood of AD transgenic mice. We found that imatinib reduces Aß-oligomers in plasma, which correlates with a reduction of AD brain features such as plaques and oligomers accumulation, neuroinflammation, and cognitive deficits. Cells exposed to imatinib and c-Abl KO mice display decreased levels of ß-CTF fragments, suggesting that an altered processing of the amyloid-beta protein precursor is the most probable mechanism behind imatinib effects. Our findings support the role of c-Abl in Aß accumulation and AD, and propose AD-PMCA as a new tool to evaluate AD progression and screening for drug candidates.

Inter-Dependent Mechanisms Behind Cognitive Dysfunction, Vascular Biology and Alzheimer's Dementia in Down Syndrome: Multi-Faceted Roles of APP.

People with Down syndrome (DS) virtually all develop intellectual disability (ID) of varying degree of severity, and also have a high risk of early Alzheimer's disease (AD). ID prior to the onset of dementia, and its relationship to the onset of dementia in DS is a complex phenomenon influenced by many factors, and scarcely understood. Unraveling the causative factors and modulators of these processes remains a challenge, with potential to be informative for both ID and AD, for the development of early biomarkers and/or therapeutic approaches. We review the potential relative and inter-connected roles of the chromosome 21 gene for amyloid precursor protein (APP), in both pathological conditions. Rare non-DS people with duplication of APP (dupAPP) get familial early onset AD (FEOAD) with virtually 100% penetrance and prominent cerebrovascular pathology, but don't suffer from ID before dementia onset. All of these features appear to be radically different in DS. On the other hand, rare individuals with partial trisomy 21 (T21) (with APP, but not DS-critical region in trisomy) have been described having ID. Likewise, partial T21 DS (without APP trisomy) show a range of ID, but no AD pathology. We review the multi-faceted roles of APP that might affect cognitive functioning. Given the fact that both Aß secretion and synaptic maturation/plasticity are dependent on neuronal activity, we explore how this conflicting inter-dependency might affect cognitive pathogenesis in a dynamic way in DS, throughout the lifespan of an individual.

Drosophila models of Alzheimer's disease: advances, limits, and perspectives.

Amyloid-ß protein precursor (AßPP) and the microtubule-associated protein tau (MAPT) are the two key players involved in Alzheimer's disease (AD) and are associated with amyloid plaques and neurofibrillary tangles respectively, two key hallmarks of the disease. Besides vertebrate models, Drosophila models have been widely used to understand the complex events leading to AD in relation to aging. Drosophila benefits from the low redundancy of the genome which greatly simplifies the analysis of single gene disruption, sophisticated molecular genetic tools, and reduced cost compared to mammals. The aim of this review is to describe the recent advances in modeling AD using fly and to emphasize some limits of these models. Genetic studies in Drosophila have revealed some key aspects of the normal function of Appl and Tau, the fly homologues of AßPP and MAPT that may be disrupted during AD. Drosophila models have also been useful to uncover or validate several pathological pathways or susceptibility genes, and have been readily implemented in drug screening pipelines. We discuss some limitations of the current models that may arise from differences in structure of Appl and Tau compared to their human counterparts or from missing AßPP or MAPT protein interactors in flies. The advent of new genome modification technologies should allow the development of more realistic fly models and to better understand the relationship between AD and aging, taking advantage of the fly's short lifespan.

Metabolic profiling of CHO-AßPP695 cells revealed mitochondrial dysfunction prior to amyloid-ß pathology and potential therapeutic effects of both PPARγ and PPARα Agonisms for Alzheimer's disease.

In this study, we performed gas chromatography time-of-flight mass spectrometry (GC-TOFMS)-based extracellular metabolic profiling on AßPP-transfected CHO cells (CHO-AßPP695) and its wildtype. Orthogonal partial least squares discriminant analysis (OPLS-DA) was then used to identify discriminant metabolites, which gave clues on the effects of AßPP transgene on cellular processes. To confirm the hypotheses generated based on the metabolic data, we performed biochemical assays to gather further evidence to support our findings. The OPLS-DA showed a robust differentiation following 24 h of incubation (Q2(cum) = 0.884) and 15 discriminant metabolites were identified. In contrast, extracellular Aß42 was identified to increase significantly in CHO-AßPP695 only after incubation for 48 h. The observed 24-h metabolic fluxes were associated with increased mitochondrial AßPP and reduced mitochondrial viabilities, which occurred before extracellular Aß accumulation. We also investigated the therapeutic potential of peroxisome proliferator-activated receptor gamma (PPARγ) agonists, namely rosiglitazone (RSG) and pioglitazone (PIO), by employing the same approach to characterize the metabolic profiles of CHO-AßPP695 treated with RSG and PIO, with or without their respective receptor blockers. Treatment with PIO was found to reduce the perturbation of the discriminant metabolites in CHO-AßPP695 to a larger extent than treatment with RSG. We also attributed the PIO effects on the lowering of Aß42, and restoration of mitochondrial activity to PPARγ and PPARα agonism, respectively. Taken together, PIO was demonstrated to be therapeutically superior to RSG. Our findings provide further insights into early disease stages in this AßPP model, and support the advancement of PIO in AD therapy.

Using the zebrafish model for Alzheimer's disease research.

Rodent models have been extensively used to investigate the cause and mechanisms behind Alzheimer's disease. Despite many years of intensive research using these models we still lack a detailed understanding of the molecular events that lead to neurodegeneration. Although zebrafish lack the complexity of advanced cognitive behaviors evident in rodent models they have proven to be a very informative model for the study of human diseases. In this review we give an overview of how the zebrafish has been used to study Alzheimer's disease. Zebrafish possess genes orthologous to those mutated in familial Alzheimer's disease and research using zebrafish has revealed unique characteristics of these genes that have been difficult to observe in rodent models. The zebrafish is becoming an increasingly popular model for the investigation of Alzheimer's disease and will complement studies using other models to help complete our understanding of this disease.

The quest for fragile X biomarkers.

BACKGROUND: Fragile X is the most common form of inherited intellectual disability and the leading known genetic cause of autism. There is currently no cure or approved medication for fragile X although various drugs target specific disease symptoms and a large number of therapeutics are in various stages of clinical development. Multiple recent clinical trials have failed on their primary endpoints indicating that there is a compelling need for validated biomarkers and outcome measures in fragile X. FINDINGS: There are currently no validated blood-based biomarkers to assess disease severity or to monitor drug efficacy in fragile X syndrome. Herein, we review candidate blood protein biomarkers including extracellular-regulated kinase, phosphoinositide 3-kinase, matrix metalloproteinase 9, amyloid-beta and amyloid-beta protein precursor. CONCLUSIONS: Bench-to-bedside plans for fragile X syndrome are severely limited by the lack of validated outcome measures. The reviewed candidate biomarkers are at early stages of validation and deserve further investigation.

Effects of Shouwu-Yizhi capsule on learning and memory and the expressions of presenilin 1,β-amyloid precursor protein mRNAs in the hippocampus following cerebral ischemia reperfusion in rats / 国际中医中药杂志

Objective To investigate the effects of Shouwu-Yizhi capsule on learning and memory, and the expressions of presenilin 1(PS1),β-amyloid precursor protein (APP) mRNAs in the hippocampus following cerebral ischemia reperfusion in rats. Methods Sprague–Dawley rats were randomly divided into a Shouwu-Yizhi group, a piracetam group, a model group, and a sham operation group with 20 rats in each group. Focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion for 2 hours. Seven days after ischemia reperfusion, the rats in the Shouwu-Yizhi and piracetam groups were administered intragastrically Shouwu-Yizhi solution (52 mg/ml) and piracetam solution (28 mg/ml) for 28 days, both in dose of 1 ml/(100 g?d) for 28 days;and the rats in the model and sham operation groups were given intragastrically equivalent volumes of normal saline. Learning and memory were tested using the Morris water maze, and the expressions of PS1 and APP mRNAs were measured using real-time quantitative fluorescent PCR. Results Water maze test showed that the escape latency (12.98±0.70s vs. 9.43±0.78s) was significantly shorter, and the frequency of crossing platform (5.08±0.39 vs. 7.62±0.43) significantly lower in the model groupthan those in the sham operation group; the escape latency (9.77±0.58s vs. 12.98±0.70s) was significantly shorter and the frequency of crossing platform (7.40±0.44 vs. 5.08±0.39) significantly lower in the Shouwu-Yizhi group than those in the model group(all P<0.01). The expressions of PS1 (0.99±0.01 vs. 1.08± 0.03)and APP (1.06±0.03 vs. 1.12±0.04) mRNAs in the hippocampus in the Shouwu-Yizhi group were significantly decreased than those in the model group (P<0.05 or 0.01). Conclusion Shouwu-Yizhi capsule may inhibit the expressions of PS1 and APP mRNAs in the hippocampus, and improve the learning and memory following cerebral ischemia reperfusion in rats.

Effect of 3-n-butylphthalide on expression of matrix metalloproteinase andβ-APP in rats / 中华老年心脑血管病杂志

Objective To study the effect of 3-n-butylphthalide on expression of MMP-2 ,MMP-9 andβ-APP in rats following chronic cerebral hypoperfusion at molecular level .Methods Seventy-two male Wistar rats were randomly divided into sham operation group ,ischemic group ,and bu-tylphthalide group (24 in each group) .Rats in ischemic group and butylphthalide group were di-vided into postischemic 7 ,14 ,30 ,60 d subgroups (6 in each group) .Expressions of β-APP ,MMP-2 , MMP-9 in each group were detected by Western blot .Results The β-APP expression level was significantly higher in postischemic 14 d ,30 d ,60 d subgroups than in postischemic 7 d subgroup (P<0 .05 ,P<0 .01) ,and in postischemic 30 d ,60 d subgroups than in postischemic 14 d sub-group (P< 0 .01) .The β-APP expression level differed greatly in 30 d and 60 d butylphthalide subgroups (P<0 .01) .The MMP-2 expression level was significantly higher in postischemic 60 d subgroup than in postischemic 30 d subgroup (P<0 .05 ,P<0 .01) .Theβ-APP and MMP-2 ex-pression levels were significantly higher in ischemic group and butylphthalide group than in sham operation group (P<0 .05 ,P<0 .01) ,and significantly lower in butylphthalide group than in is-chemic group (P< 0 .01) .Conclusion MMP-2 and β-APP tend to change similarly and are in-volved in blood brain barrier destruction and amyloid deposition .Butylphthalide intervenes in am-yloid deposition by downregulating the expression of MMP-2 andβ-APP .