胱天蛋白酶-3在不同年龄猕猴脑组织中的表达

Expression of caspase-3 in rhesus monkey brains at different ages

目的 对胱天蛋白酶 3在正常衰老的灵长类动物 (猕猴 )脑中的表达和分布状况进行初步探讨。 方法 健康的 4岁及 2 0岁雌性猕猴各 4只 ,经全身麻醉后取脑 ,用免疫组织化学和免疫印迹法观察额叶皮质、海马和小脑胱天蛋白酶 3的表达和分布。 结果 额叶皮质胱天蛋白酶 3的免疫反应性很低 ,而海马的CA1、CA3和CA4区可见低至中度阳性染色的锥体细胞 ,小脑皮质的少数浦肯野细胞呈强阳性染色。在 2 0岁猴上述 3个脑部位中 ,除运动区第V层偶见强阳性染色的大锥体细胞外 ,其余与成年组无差别。免疫印迹显示 ,3个脑区胱天蛋白酶 3含量无明显的脑区或年龄差异。 结论 胱天蛋白酶 3在发育成熟后的猕猴脑内持续表达 ,但表达量及阳性细胞的分布与年龄无关。

Objective To study the in vivo expression patterns of caspase-3 in normally aged primate brain. Methods Fresh brain tissue was taken from 4-year-old and 20-year-old female rhesus monkeys,4 for each age group. In vivo distribution of caspase-3-positive cells and its protein levels in different brain regions were investigated by immunohistochemical and immunoblot means,respectively. Results In the frontal cortex,most neurons lacked detectable caspase-3 immunoreactivity,whereas low to moderate caspase-3 immunostaining was found mainly in pyramidal cells in CA1,CA3 and CA4 subdivisions of hippocampus. And in the cerebellum,a small number of Purkinje cells were strongly stained in their cytosol and dendrites,while their nuclei lacked staining. Age-related changes in caspase-3 expression pattern were not found. Immunostaining of motor cortex in aged monkeys localized strong caspase-3 immunoreactivity to a limited number of large pyramidal cells in layer V. Immunoblotting revealed the 32 000 caspase-3 progenitor in all three brain regions. There were no differences in caspase-3 expression levels as a function of either brain region or age of animals. Conclusions These results suggest that caspase-3 is constitutively expressed in matured primate brain and there is no significant age-related change in its expression.