AUTHOR=Wang Xiu-Lian , Zeng Ji , Feng Jin , Tian Yi-Tao , Liu Yu-Jian , Qiu Mei , Yan Xiong , Yang Yang , Xiong Yan , Zhang Zhi-Hua , Wang Qun , Wang Jian-Zhi , Liu Rong 

TITLE=Helicobacter pylori filtrate impairs spatial learning and memory in rats and increases β-amyloid by enhancing expression of presenilin-2

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=6

YEAR=2014

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2014.00066

DOI=10.3389/fnagi.2014.00066

ISSN=1663-4365

ABSTRACT=<p><italic>Helicobacter pylori (H. pylori)</italic> infection is related with a high risk of Alzheimer's disease (AD), but the intrinsic link between <italic>H. pylori</italic> infection and AD development is still missing. In the present study, we explored the effect of <italic>H. pylori</italic> infection on cognitive function and β-amyloid production in rats. We found that intraperitoneal injection of <italic>H. pylori</italic> filtrate induced spatial learning and memory deficit in rats with a simultaneous retarded dendritic spine maturation in hippocampus. Injection of <italic>H. pylori</italic> filtrate significantly increased Aβ<sub>42</sub> both in the hippocampus and cortex, together with an increased level of presenilin-2 (PS-2), one key component of γ-secretase involved in Aβ production. Incubation of <italic>H. pylori</italic> filtrate with N2a cells which over-express amyloid precursor protein (APP) also resulted in increased PS-2 expression and Aβ<sub>42</sub> overproduction. Injection of <italic>Escherichia coli</italic> (<italic>E.coli</italic>) filtrate, another common intestinal bacterium, had no effect on cognitive function in rats and Aβ production in rats and cells. These data suggest a specific effect of <italic>H. pylori</italic> on cognition and Aβ production. We conclude that soluble surface fractions of <italic>H. pylori</italic> may promote Aβ<sub>42</sub> formation by enhancing the activity of γ-secretase, thus induce cognitive impairment through interrupting the synaptic function.</p>