锌离子与锌转运体6在APP/PS1转基因小鼠小脑内的分布

 目的 研究游离锌离子和锌转运体6（zinc transporter 6,ZnT6）在APP/PS1转基因小鼠小脑内的分布。方法 应用浸入式金属自显影技术（AMG）和免疫组织化学染色标记游离锌离子、ZnT6和淀粉样前体蛋白（amyloid precursor protein,AYY）,通过免疫荧光染色和共聚焦激光扫描显微镜观察ZnT6和β-淀粉样蛋白（β-amyloid,Aβ）在老年斑内的定位,并分析锌离子、ZnT6与APP和Aβ分布的相关性。结果 游离锌离子、ZnT6和APP免疫阳性反应产物均定位于老年斑内,老年斑主要分布于小脑分子层,浦肯野细胞层和颗粒层分布较少;ZnT6和Aβ荧光双标的结果进一步证实两者共存于老年斑内。结论 APP/PS1转基因小鼠小脑Aβ老年斑内有大量的ZnT6蛋白表达,并聚集着大量的锌离子,提示锌离子可能参与小脑Aβ老年斑的形成,而ZnT6在老年斑内锌离子的聚集过程中起着重要的调节作用。

Distribution of zinc ions and zinc transporter-6 in the APP/PS1 transgenic mouse cerebellum

Objective To investigate the distribution of free zinc ions and zinc transporter-6 (ZnT6) in the APP/PS1 transgenic mouse cerebellum. Methods Immersion autometallography (AMG) and immunohistochemistry were used to analyze the distribution of free zinc ions, amyloid precursor protein (APP) and ZnT6 in the APP/PS1 transgenic mouse cerebellum, respectively. Immunofluorescence and confocal laser scanning microscopy were used to analyze the relation between ZnT6 and Aβ in senile plaques. Results Zinc ions, APP and ZnT6 were mainly located in the amyloid plaques, which were predominately located in the molecular layer. The Purkinje cell layer and granular layer only contained a few plaques. Confocal microscopic results revealed a colocalization of ZnT6 and Aβ in the senile plaques. Conclusions The abundant expression of ZnT6 and accumulation of zinc ions in the β-amyloid plaques of the APP/PS1 transgenic mouse cerebellum, suggesting that zinc ions might be involved in the formation of senile plaques, while ZnT6 might play an important role in the regulation of zinc accumulation during the pathological process of Alzheimer’s disease.