[Change of Ankyrin G Promoter Activity Following Treatment with Sodium Valproate at Different Concentrations].

OBJECTIVE: To investigate whether sodium valproate (VPA) directly regulates the activity of Ankyrin G(AnkG) promoter in vitro. METHODS: The mouse AnkG promoter sequence was identified by comparing both human and mouse AnkG promoter sequences. The promoter was amplified from C57BL/6 mouse genome DNA and cloned into pGL3 Luciferase reporter vector. The Luciferase activity was detected in N2a and 293T cells and then treated with 0,0.5, and 1 mmol/L VPA for 12 h. The transcription activity of AnkG promoter in cells and the activity of VPA-treated Luciferase reporter vector in cells were detected using dual Luciferase reporter assay. RESULTS: The AnkG promoter clone and its expression vector were successfully established, as confirmed by enzyme digestion and sequencing. The AnkG promoter showed high transcription activity in both N2a and 293T cells. The Luciferase activity was significantly induced following 0.5 mmol/L VPA treatment in both N2a and 293T cells. CONCLUSIONS VPA can up-regulate the AnkG expression via directly increasing its transcription activity. Thus, the in vivo AnkG expression may be directly regulated by the VPA at transcriptional level.

Effects of analog P165 of amyloid precursor protein 5-mer peptide on learning, memory and brain insulin receptors in the rat model of cognitive decline.

We aim to study the therapeutic efficacy of analog P165 of amyloid precursor protein 5-mer peptide in streptozotocin (STZ)-induced cognitive decline model. Rats were divided into four groups: control, STZ, STZ+P165, and STZ+rosiglitazone (RSG). STZ model was established by intracerebroventricular injection of STZ. Three weeks following surgery, rats received daily gavage administration of distilled water (control and STZ groups), P165 (STZ+P165), or RSG (STZ+RSG) for four consecutive weeks. Learning and memory abilities were assessed with the Morris water maze test. Insulin-like growth factor-1 (IGF-1) was detected by ELISA. Expressions of insulin receptor-ß (IR-ß), insulin receptor substrate-1 (IRS-1), serine/threonine kinase (Akt), and phosphorylation of CREB (p-CREB) were observed by immunohistochemistry. Both P165 and RSG significantly reduced the escape latency relative to the STZ group (P165, P < 0.05; RSG, P < 0.01). STZ model rats had reduced levels of IGF-1 relative to control, and this deficit was attenuated in the STZ+P165 group (P < 0.01). IR and IRS-1 were elevated in STZ rats, and these levels were restored to near control in the STZ+P165 and STZ+RSG groups (P < 0.01). Our findings demonstrate that P165 and RSG improved hippocampus-dependent spatial learning and memory in STZ rats by regulating the insulin signaling pathway.

[Guiding principles of clinical research on mild cognitive impairment (protocol)].

Mild cognitive impairment (MCI), as a nosological entity referring to elderly people with MCI but without dementia, was proposed as a warning signal of dementia occurrence and a novel therapeutic target. MCI clinical criteria and diagnostic procedure from the MCI Working Group of the European Alzheimer's Disease Consortium (EADC) may better reflect the heterogeneity of MCI syndrome. Beijing United Study Group on MCI funded by the Capital Foundation of Medical Developments (CFMD) proposed the guiding principles of clinical research on MCI. The diagnostic methods include clinical, neuropsychological, functional, neuroimaging and genetic measures. The diagnostic procedure includes three stages. Firstly, MCI syndrome must be defined, which should correspond to: (1) cognitive complaints coming from the patients or their families; (2) reporting of a relative decline in cognitive functioning during the past year by the patient or informant; (3) cognitive disorders evidenced by clinical evaluation; (4) activities of daily living preserved and complex instrumental functions either intact or minimally impaired; and (5) absence of dementia. Secondly, subtypes of MCI have to be recognized as amnestic MCI (aMCI), single non-memory MCI (snmMCI) and multiple-domains MCI (mdMCI). Finally, the subtype causes could be identified commonly as Alzheimer disease (AD), vascular dementia (VaD), and other degenerative diseases such as frontal-temporal dementia (FTD), Lewy body disease (LBD), semantic dementia (SM), as well as trauma, infection, toxicity and nutrition deficiency. The recommended special tests include serum vitamin B12 and folic acid, plasma insulin, insulin-degrading enzyme, Abeta40, Abeta42, inflammatory factors. Computed tomography (or preferentially magnetic resonance imaging, when available) is mandatory. As measurable therapeutic outcomes, the primary outcome should be the probability of progression to dementia, the secondary outcomes should be cognition and function, and the supplement outcome should be the syndrome defined by traditional Chinese medicine. And for APOE epsilon4 carrier, influence of the carrier status on progression rate to dementia and the effect of treatment should be evaluated.

[An explanation on "guiding principles of clinical research on mild cognitive impairment (protocol)"].

In order to provide the "guiding principles of clinical research on mild cognitive impairment (MCI) (protocol)" edited by Beijing United Study Group on MCI of the Capital Foundation of Medical Developments (CFMD) with evidence support, clinical criteria, subtypes, inclusion and exclusion of MCI, and use of rating scales were reviewed. The authors suggested that MCI clinical criteria and new diagnosis procedure from the MCI Working Group of the European Alzheimer's disease Consortium (EADC) may better reflect the heterogeneity of MCI syndrome. Diagnostic rating scales including Clinical Dementia Rating (CDR), Global Deterioration Scale (GDS), Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and Instrumental Activities of Daily Living (IADL) are very useful in definition of MCI but can not replace its clinical criteria. Absence of major repercussions on daily life in patients with MCI was emphasized, but the patients may have minimal impairment in complex IADL. According to their previous research, the authors concluded that highly recommendable neuropsychological scales with cut-off scores in the screening of MCI cases should include Mini-Mental State Examination (MMSE), logistic memory test such as Delayed Story Recall (DSR), executive function test such as Clock Draw Test (CDT), language test such as Verbal Category Fluency Test (VCFT), etc. And finally, the detection of biological and neuroimaging changes, including atrophy in hippocampus or medial temporal lobe in patients with MCI, was introduced.

Increased expression of the Nogo receptor in the hippocampus and its relation to the neuropathology in Alzheimer's disease.

Alzheimer's disease (AD) is the most prevalent cause of dementia in human beings. Its best-known pathologic feature is the presence of senile plaques and neurofibrillary tangles in the brain. Nogo-66 receptor (NgR) is believed to contribute to the inhibitory activities of axon regeneration after injury. This study investigated the expression of NgR in the hippocampus and its relation to the pathologic changes of AD using immunohistochemistry and double-labeling immunofluorescence methods. The results showed that NgR immunoreactivity was present in more than 50% of the pyramidal layer cells of the CA1 to CA4 subfields of the hippocampus. No significant difference was observed in the number of NgR immunopositive cells in the CA1 to CA4 subfields between patients with AD and control subjects, whereas the ratio of NgR immunopositive cells to the total number of pyramidal layer cells was revealed to be significantly higher in the CA1 and CA2 subfields of the hippocampus of patients with AD than that in the same region of the control subjects. Moreover, high numbers of AT-8 immunopositive cells were found to be double-labeled with NgR in the CA1 subfields of patients with AD, whereas only few NgR deposits were observed in the senile plaques of the hippocampus in these patients. These results suggest that NgR may be related to the formation of tangles in AD.

[Effect of GETO on expression of protein in postsynaptic dense zone of Alzheimer's disease model rats].

OBJECTIVE: To observe the effect of GETO on expression of PSD-95 and Shank-1 protein in postsynaptic dense zone in Alzheimer disease (AD) model rats. METHODS: The AD model rats were established by beta-amyloid protein (Abeta(1-42)) injection into hippocampus CA1 zone. They were assigned into the model group, the donepezil treated group and the GETO treated group, besides, a normal group was set for control. Four weeks after modeling, Morris water maze test was applied to determine the learning and memory function of the AD rats, the number of PSD-95 and Shank-1 protein positive neuron as well as the optical density (OD) in post-synaptic dense zone of hippocampus CA1 area were determined by using immuno-histochemical stain and computerized graphic analysis techniques. RESULTS: Morris water maze test showed that the mean escape latent period (MELP) of the model rats obviously prolonged than that of the normal rats, and the times of traversing flat roof obviously decreased (P < 0.01), while in the model rats after being treated by GETO, the two parameters were significantly shortened and increased respectively (P < 0.01), reaching the level insignificantly different to those in the donepezil group and the normal group. Immunohistochemical test showed that the number of positive stained neuron of PSD-95 and Shank-1 in hippocampus CA1 zone in the model group was significantly different to those in the normal group (P < 0.01), while in the GETO group those indexes were insignificantly different to those in the donepezil group and the normal group (P > 0.05), but showed a significant difference when compared with those in the model group (P < 0.05). CONCLUSION: GETO can obviously improve the function of learning and memory of AD rats induced by Abeta(1-42), and the mechanism may be associated with its actions in improving expressions of PSD-95 and Shank-1 protein in hippocampus CA1 zone, and recovering the structure and function of synapse and enhancing its plasticity.

A novel neurotrophic peptide: APP63-73.

The objective of this study was to find out which N-terminal segment/s of amyloid precursor protein (APP) has any neurotrophic properties, since soluble APP-alpha (sAPP-alpha) has neurotrophic effects. We investigated neurotrophic properties of eight peptide segments of N-terminal APP. The APP63-73 was able to enhance neuronal growth; augment axonal and cell body growth in human neuroblastoma cell line, SH-SY5Y. Neurotrophic effects of chronic APP63-73 treatment were assessed in vivo using streptozotocin-induced diabetes and ovariectomized rats. Thus, this study demonstrated that APP63-73 peptide has neurotrophic effects both in vivo and in vitro.

Effect of amyloid precursor protein 17mer peptide on microtubule structure and tau protein hyperphosphorylation in hippocampal neurons of experimental diabetic mice.

The objective of this study was to investigate whether microtubular structure changes and tau protein hyperphosphorylation exist in hippocampal neurons of experimental diabetic mice, and to study the effect of amyloid precursor protein 17mer peptide. The results showed that the microtubules of hippocampal neurons of diabetic mice manifested prominent signs of fragmentation and dissolution, tau protein is hyperphosphorylated at Ser 199/Thr 202 sites, enzymes related to the phosphorylation and dephosphorylation of tau protein were diminished. The administration of amyloid precursor protein 17mer peptide could ameliorate the foregoing changes in diabetic mice. These results indicated that protein synthesis in the brain tissue of diabetic mice decreased. Amyloid precursor protein 17mer peptide acted as a neuroprotective agent that globally alleviates the disturbances due to impaired energy metabolism in diabetic mice.

[Research progress on Alzheimer's disease: pathogenesis and medical therapy].

Alzheimer's disease (AD) is a common disease in elder people. Its incidence rate is about 5% in people above 60 years old. It has become an important factor that seriously impacts the development of families and society, and caused wildly attention all over the world. In this article, we discuss the mechanisms of AD in four aspects and put forward the strategies of drug therapy.

[The effect of jiunaoyizhi capsul on signal transduction pathway of SY5Y cell lines].

OBJECTIVE: To observe the effect of Jiunaoyizhi capsul on the signal transduction pathway of SY5Y cell lines and explore the mechanism of the function of the capsul's enhancing neuronal growth. METHOD: Human neuroblastoma was used as cell models and they were divided into control group and experimental group. Supernatant of cell lysate was taken and immunoprecipitation was done with antibodies to proteins related to signal transduction pathway, and the immunoprecipitates were analyzed by Western blotting. RESULT: After treatment with Jiunaoyizhi capsul, expression of Akt/PKB, CREB, P-CREB was clearly increased and expression of cytochrome C decreased more than the control group. CONCLUSION: Jiunaoyizhi capsul can promote expression of some proteins related with signal transduction pathway in SY5Y cell lines. Mechanism of Jiunaoyizhi capsul's enhancing neuronal growth is relevant to expression of some proteins in signal transduction pathway.

[The effect of lishi No.5 formula on the growth of human neuroblastoma cell line SY5Y].

OBJECTIVE: To investigate the effect of Lishi No.5 formula on the growth of human neuroblastoma cell line SY5Y and find out the most effective drug dose. METHOD: SY5Y cells were administrated by Lishi No.5 formula in different concentration. MTT metabolic rate was measured as the cell survival rate, then the dose-effect curve was made. LDH leakage rate, axonal length and area of cell body were used as the indicators. RESULT: In 0.125-0.75 g x L(-1) Lishi No. 5 formula could increase the cell survival rate and MTT metabolic rate, decreased LDH leakage rate, and enhance axonal length and area of cell body, compared with control group. CONCLUSION: Lishi No.5 formula has the neurotrophic effect and can induce the survival of neuron.

Tubastatin A/ACY-1215 improves cognition in Alzheimer's disease transgenic mice.

Histone deacetylase 6 (HDAC6) is currently being discussed as a promising therapeutic target for the treatment of Alzheimer's disease (AD). Mounting evidence indicates that increased HDAC6 expression may contribute to AD-associated neurodegeneration, although beneficial effects have also been identified. In the present study, we tested the potential of two selective HDAC6 inhibitors, tubastatin A and ACY-1215, to rescue cognitive deficits in a mouse model of AD. We found that both tubastatin A and ACY-1215 alleviated behavioral deficits, altered amyloid-ß (Aß) load, and reduced tau hyperphosphorylation in AD mice without obvious adverse effects. Our data suggested that tubastatin A and ACY-1215 not only promoted tubulin acetylation, but also reduced production and facilitated autophagic clearance of Aß and hyperphosphorylated tau. Further, the decreased hyperphosphorylated tau and increased tubulin acetylation may account for the improved microtubule stability in AD mice after tubastatin A/ACY-1215 treatment. These preclinical results support the detrimental role of HDAC6 in AD, and offer prospective approaches for using tubastatin A/ACY-1215 as potential therapeutic strategy for AD.

Regional and cell-type specific distribution of HDAC2 in the adult mouse brain.

The effects of epigenetics on brain functions are not completely understood, but histone deacetylases (HDACs) are known to affect brain function and dysfunction by mediating the acetylation status of target proteins, thereby affecting gene expression. The current study used immunochemistry to illuminate the regional distribution of one member of the HDAC family, HDAC2, in the C57BL/6J mouse brain. Our data show that HDAC2 is ubiquitously expressed throughout the mouse brain and is localized primarily within the cell nucleus. Using double-immunofluorescence, we demonstrated HDAC2 expression in neuronal cells, including cholinergic, serotonergic and catecholaminergic neurons, as well as postsynaptic glutamatergic and GABAergic neurons. HDAC2 was also observed in oligodendrocytes, but not in astrocytes or microglia. These detailed immunological studies illuminate the distribution of HDAC2 throughout the mouse brain and will facilitate investigation of the roles of HDAC2 in brain function and neurological disorders.

Amyloid precursor protein 17-mer peptide ameliorates hippocampal neurodegeneration in ovariectomized rats.

Amyloid precursor protein 17-mer peptide (APP 17-mer peptide) is an active fragment of amyloid precursor protein (APP) in the nervous system that mediates various neuronal activities and functions. Estrogen deprivation during menopause disproportionately increases the risk of many neurodegenerative diseases, including Alzheimer's disease (AD). Currently, therapeutic approaches to treat Alzheimer's disease are less than effective. We have previously shown that APP 17-mer peptide participates in neuronal function in aged-hippocampal neurons. In this study, we investigate the effects of estrogen and APP 17-mer peptide on hippocampal neurodegeneration in ovariectomized rats. The results showed that decreases in learning and memory function in ovariectomized rats were associated with degenerative changes in hippocampal neurons. Estrogen deprivation also enhances apoptotic cell death and decreases expression of the anti-apoptotic protein Bcl-2. Administration of APP 17-mer peptide ameliorates changes associated with estrogen deprivation without affecting estrogen levels. These results indicate that APP 17-mer peptide may prevent neurodegeneration caused by estrogen deficiency. Our findings also suggest that estrogen deficiency-induced neurodegeneration is regulated by activation of an intracellular "cross talk" signaling pathway, connecting neurotrophins with APP 17-mer peptide.