Activation of 5-HT(2C) receptor promotes the expression of neprilysin in U251 human glioma cells.

Abeta accumulation, a hallmark of Alzheimer's disease, promotes the disease progress in multiple facets. Abeta is formed through amyloidogenic cleavage pathway of amyloid precursor protein (APP). Production of Abeta can be decreased via activation of 5-HT2C receptor, which enhances alternative APP non-amyloidogenic cleavage. Besides, as one of the best characterized Aß degrading enzymes, neprilysin (NEP) in AD progress has drawn more and more attention. We investigated whether there exists any connection between 5-HT2C receptor and NEP expression. The mRNA and protein expressions of NEP were increased after treatment of 5-HT2C receptor agonist RO-60-0175 in concentration- and time-dependent manners, and NEP expression was decreased after treatment of 5-HT2C receptor antagonist SB242084 correspondingly. These results suggest that 5-HT2C receptor may inhibit the Abeta formation by promoting NEP expression. The underlying mechanism will be explored in follow-up study and may provide potential target for AD therapy.

Rapid Identification of Alcohol Compounds by Cyclic Chemiluminescence / 分析化学

Rapid discrimination of compounds with similar structures and properties is a hot topic in analytical chemistry. In this study, a cyclic chemiluminescence (CCL) system was designed by using nano-magnesium oxide as catalyst. The effects of reactant concentration, reaction temperature and detection wavelength on CCL analysis were studied. It was found that the CCL signal satisfied the first order exponential decay law. Each reaction had an exponential decay equation (EDE) describing its signal change law. The initial variable A was proportional to the reactant concentration. The decay-coefficient k was a characteristic constant that was independent of the reactant concentration. For iso-butanol, it's A-values versus concentration was linear in 0. 89-14. 24 mg / L, the average of k-value in this range was 32. 0 with a RSD of 2. 2% . Thus, qualitative and quantitative analysis could be conducted according to the A and k values. The system was used to analyze eight kinds of alcohol compounds, and it was found that there were significant differences in the k-values for different alcohols. For example, the k-values for n-butanol, iso-butanol and sec-butanol were 27. 2 ±0. 2, 32. 0±0. 8 and 19. 5±0. 1, respectively.