The Efficacy of General Practitioner Assessment of Cognition in Chinese Elders Aged 80 and Older.

OBJECTIVES: This study examined the efficacy of the General Practitioner Assessment of Cognition-Chinese version (GPCOG-C) in screening dementia and mild cognitive impairment (MCI) among older Chinese. METHODS: Survey questionnaires were administered to 293 participants aged 80 or above from a university hospital in mainland China. Alzheimer disease and MCI were diagnosed in light of the National Institute on Aging and the Alzheimer's Association (NIA/AA) criteria. The sensitivity and specificity of GPCOG-C and Mini-Mental State Examination (MMSE) in screening dementia and MCI were compared to the NIA/AA criteria. RESULTS: The GPCOG-C had the sensitivity of 62.3% and specificity of 84.6% in screening MCI, which had comparable efficacy as the NIA/AA criteria. In screening dementia, GPCOG-C had a lower sensitivity (63.7%) than the MMSE and a higher specificity (82.6%) higher than the MMSE. CONCLUSIONS: The GPCOG-C is a useful and efficient tool to identify dementia and MCI in older Chinese in outpatient clinical settings.

MicroRNA-26a/Death-Associated Protein Kinase 1 Signaling Induces Synucleinopathy and Dopaminergic Neuron Degeneration in Parkinson's Disease.

BACKGROUND: Death-associated protein kinase 1 (DAPK1) is a widely distributed serine/threonine kinase that is critical for cell death in multiple neurological disorders, including Alzheimer's disease and stroke. However, little is known about the role of DAPK1 in the pathogenesis of Parkinson's disease (PD), the second most common neurodegenerative disorder. METHODS: We used Western blot and immunohistochemistry to evaluate the alteration of DAPK1. Quantitative polymerase chain reaction and fluorescence in situ hybridization were used to analyze the expression of microRNAs in PD mice and patients with PD. Rotarod, open field, and pole tests were used to evaluate the locomotor ability. Immunofluorescence, Western blot, and filter traps were used to evaluate synucleinopathy in PD mice. RESULTS: We found that DAPK1 is posttranscriptionally upregulated by a reduction in microRNA-26a (miR-26a) caused by a loss of the transcription factor CCAAT enhancer-binding protein alpha. The overexpression of DAPK1 in PD mice is positively correlated with neuronal synucleinopathy. Suppressing miR-26a or upregulating DAPK1 results in synucleinopathy, dopaminergic neuron cell death, and motor disabilities in wild-type mice. In contrast, genetic deletion of DAPK1 in dopaminergic neurons by crossing DAT-Cre mice with DAPK1 floxed mice effectively rescues the abnormalities in mice with chronic MPTP treatment. We further showed that DAPK1 overexpression promotes PD-like phenotypes by direct phosphorylation of α-synuclein at the serine 129 site. Correspondingly, a cell-permeable competing peptide that blocks the phosphorylation of α-synuclein prevents motor disorders, synucleinopathy, and dopaminergic neuron loss in the MPTP mice. CONCLUSIONS: miR-26a/DAPK1 signaling cascades are essential in the formation of the molecular and cellular pathologies in PD.

1,5-dicaffeoylquinic acid protects primary neurons from amyloid ß 1-42-induced apoptosis via PI3K/Akt signaling pathway.

BACKGROUND: Recently, 1,5-dicaffeoylquinic acid (1,5-DQA), a caffeoylquinic acid derivative isolated from Aster scaber, was found to have neuroprotective effects. However, the protective mechanisms of 1,5-DQA have not yet been clearly identified. The purpose of this study was to explore the protective mechanisms of 1,5-DQA on neuronal culture. METHODS: We investigated the neuroprotective effects of 1,5-DQA against amyloid ß(1-42) (Aß(42))-induced neurotoxicity in primary neuronal culture. To evaluate the neuroprotective effects of 1,5-DQA, primary cultured cortical neurons from neonate rats were pretreated with 1,5-DQA for 2 hours and then treated with 40 µmol/L Aß(42) for 6 hours. Cell counting kit-8, Hoechst staining and Western blotting were used for detecting the protective mechanism. Comparisons between two groups were evaluated by independent t test, and multiple comparisons were analyzed by one-way analysis of variance (ANOVA). RESULTS: 1,5-DQA treated neurons showed increased neuronal cell viability against Aß(42) toxicity in a concentration-dependent manner, both phosphoinositide 3-kinase (PI3K)/Akt and extracellular regulated protein kinase 1/2 (Erk1/2) were activated by 1,5-DQA with stimulating their upstream tyrosine kinase A (Trk A). However, the neuroprotective effects of 1,5-DQA were blocked by LY294002, a PI3K inhibitor, but not by PD98059, an inhibitor of mitogen-activated protein kinase kinase. Furthermore, 1,5-DQA's anti-apoptotic potential was related to the enhanced inactivating phosphorylation of glycogen synthase kinase 3ß (GSK3ß) and the modulation of expression of apoptosis-related protein Bcl-2/Bax. CONCLUSION: These results suggest that 1,5-DQA prevents Aß(42)-induced neurotoxicity through the activation of PI3K/Akt followed by the stimulation of Trk A, then the inhibition of GSK3ß as well as the modulation of Bcl-2/Bax.

alpha-Synuclein redistributed and aggregated in rotenone-induced Parkinson's disease rats.

Objective To observe the influence of rotenone on the distribution of alpha-synuclein (ASN) in rat model of Parkinson's disease (PD). Methods Wistar rats were randomly divided into two groups and received 2 mg/kg rotenone (s.c.) or sunflower oil (as control group) for about 4 weeks. The hippocampus, substantia nigra and striatum of brain were observed. Hematoxylin and eosin stain were used to observe the Lewy body like inclusion. The expression of tyrosine hydroxylase (TH) or ASN protein was determined by anti-TH or anti-alpha-synuclein immunohistochemistry, respectively. Results In control rats, ASN protein distributed widely in brain, especially in hippocampus, cortex and striatum. Rotenone obviously increased TH positive neurons and fibers loss in substantia nigra and striatum (P < 0.05). In rotenone treated rats, ASN positive cells increased in global brain but not distributed in an even manner. In substantia nigra, ASN positive stuff was found aggregate in both cytoplasm and nucleus, and some formed spherical inclusion; in striatum, ASN positive neurites end aggregated and agglomerated around neurons; and in hippocampus, few dot-like ASN were aggregated in cell body, and no notable change was found in nucleus. Conclusion In rotenone administrated PD rats, ASN protein aggregated in several brain regions but most obviously in striatum and substantia nigra, and the distribution region of ASN was changed from peri-synapse to the cytoplasm and nucleus of dopaminergic neuron.