Association study in Alzheimer’s disease of single nucleotide polymorphisms implicated with coffee consumption

There is evidence from animal and in vitro models of the protective effects of caffeine in Alzheimer’s disease. The suggested mechanisms through which caffeine may protect neurons against Alzheimer’s disease pathology include the facilitation of beta-amyloid clearance, upregulation of cholinergic transmission, and increased neuronal plasticity and survival. Epidemiological studies support that Alzheimer’s disease patients consume smaller amounts of coffee beverages throughout their lives as compared to age-matched cognitively healthy individuals. Objective: The aim of the present study was to determine whether the negative association between Alzheimer’s disease and coffee consumption may be influenced by a common genetic predisposition, given the fact that the pattern of coffee consumption is determined by both environmental and genetic factors. Method: We conducted an in silico search addressing the association between genetic polymorphisms related to coffee consumption and the diagnosis of Alzheimer’s disease. We further investigated the interactions between genes located in regions bearing these polymorphisms. Results: Our analysis revealed no evidence for a genetic association (nor interaction between related proteins) involving coffee consumption and Alzheimer’s disease. Discussion: The negative association between Alzheimer’s disease and coffee consumption suggested by epidemiological studies is most likely due to environmental factors that are not necessarily regulated by genetic background...

Efeitos do lítio sobre a expressão e atividade das enzimas fosfolipase A2 e glicogênio sintase quinase 3beta e sua relação com o estado de fosforilação da proteína tau / Effects of lithium on the expression of the enzymes activity phospholipase A2 and glycogen synthase kinase 3beta and its relationship with the phosphorylation state of tau protein

O presente estudo comparou o efeito do tratamento crônico com lítio em doses subterapêuticas (0,02mM e 0,2mM) e dose terapêutica (2mM) em cultura primária de neurônios corticais e hipocampais. As amostras foram analisadas e comparadas com o grupo controle (sem tratamento) tanto para os neurônios corticais, como para os neurônios hipocampais. O objetivo do estudo foi: 1) avaliar, nessas culturas celulares, a atividade de diferentes quinases (PKA, CaMKII, AKT e GSK3beta), diferentes sítio de fosforilação da Tau (Ser, 199, 205, 214, 396, C-terminal e seis isoformas), a partir da inibição da PLA2 pelo lítio; 2) Investigar as vias de sinalização envolvidas na modulação do estado de fosforilação da proteína tau a partir da inibição da PLA2 em culturas primárias de neurônios; 3) avaliar, simultaneamente, a expressão de fatores neurotróficos (BDNF) e citocinas (GM-CSF, IL-1b, IL-2, IL-4, IL-5, IL6, IL-10, IL-12, IFN-y e TNF-alfa) mediante o tratamento de neurônios primários com lítio e 4) avaliar expressão gênica por microarray das culturas tratadas com diferentes doses, subterapêuticas e terapêutica, de cloreto de lítio. Nossos resultados sugerem uma dissociação de efeitos em neurônios corticais dos observados em neurônios hipocampais. O lítio aumentou a atividade enzimática da iPLA2 e da cPLA2, tanto em neurônios corticais como em neurônios hipocampais. A atividade da GSK3beta foi inibida pelo tratamento crônico com lítio em neurônios hipocampais e apresentou efeito contrário em neurônios corticais. Observamos comportamentos diferentes das diferentes proteínas analisadas em culturas de neurônios corticais e hipocampais, e não tivemos significância estatística para as alterações na proteína tau. O tratamento nas doses subterapêuticas aumentou a secreção de citocinas pró-inflamatórias tanto em neurônios corticais quanto em neurônios hipocampais.

The present study compared the effect of lithium chronic treatment with subtherapeutic doses (0.02mM and 0.2mM) and therapeutic dose (2mM) in primary cortical and hippocampal neurons cell culture. This samples were analyzed and compared with the control group (no treatment). The study's goal was: 1) to evaluate in these Cell Culture a different activity kinases (PKA, CaMKII, AKT and GSK3beta), different phosphorylation site of the Tau (199, 205, 214, 396, C-terminal and Six isoforms) and PLA2 inhibition; 2) To investigate how signaling pathways involved in modulation of tau phosphorylation from the inhibition of PLA2 in primary cultures of neurons; 3) analyze an expression of neurotrophic factors (BDNF) and cytokines (GM-CSF, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IFNy TNFalfa 4) to evaluate gene expression via microarray with different doses of lithium treatment. Our results suggest a dissociation effects on cortical and hippocampal neurons cell culture. Lithium increased the enzyme activity of iPLA2 and cPLA2, in both cortical and hippocampal neurons. The GSK3beta the activity was inhibited by chronic treatment with lithium in hippocampal neurons and presented contrary effect on cortical neurons. We observe not statistics significance on tau protein. The treatment at subtherapeutic and therapeutic doses increased the secretion of pro and anti-inflammatory cytokines both in cortical and hippocampal neurons.