米诺环素体外抗Aβ25-35对大鼠皮质神经元毒性初步研究

 目的研究米诺环素对Aβ25-35导致大鼠皮质神经元毒性的保护作用。方法培养大鼠皮质神经元，复制Aβ25-35诱导的神经元毒性模型。通过测定LDH的活性观察米诺环素对Aβ25-35产生的细胞死亡的影响，采用Hoechest 33258核染色后相差显微镜下细胞形态的变化以及DNA琼脂糖凝胶电泳观察米诺环素对Aβ25-35产生的细胞凋亡的影响，并通过底物测定观察米诺环素对Aβ25-35导致的胱冬氨酸酶3（caspase3）活性的变化。结果米诺环素能明显对抗Aβ25-35诱导的神经元毒性，减少LDH的释放，促进神经元存活。同时还能明显的对抗Aβ25-35引起的神经元染色质浓缩、核固缩和DNA片段化的作用。此外，米诺环素也能明显抑制Aβ25-35诱导的神经元caspase3活性的升高。结论米诺环素能抑制Aβ25-35诱导的神经元凋亡，这种作用可能是通过抑制caspase3的活性来实现的。

Preliminary study on minocycline against β-amyloid protein 25-35-induced toxicity in vitro

OBJECTIVE To study the protective effect of minocycline on beta-amyloid protein 25-35(Aβ25-35)-induced toxicity in cultured rat cortical neurons．METHOD S The toxicity model was established by treated neurons with Aβ25-35 in cultured rat cortical neurons．Cell death was determined by the release of cellular lactate dehydrogenase (LDH). Apoptosis was evaluated by Hoechest 33258 staining and DNA gel electrophoresis．The activity of caspase3 was assayed by fluorescent substrat．RESULTS Minocycline reduced the level of LDH in the medium of the neurons treated with Aβ25-35 and kept the survival of neurons．Aβ25-35 induced nuclic condensation and DNA fragment in neurons at 24 h.These effects were attenuated by minocycline．In addition，the activity of caspase3 was increased in neurons after treated with Aβ25-35. The activity of caspase3 was inhibited．CONCLUSION Minocycline inhibited Aβ25-35-induced apoptosis in cultured cortical neurons．The effects of minocycline might be through inhibiting the activation of caspase3 induced by Aβ25-35.