Objective: To observe effects of tanshinone (Tan) IIA on the apoptosis and expressions of p53 and pp53 in brain tissues of rats with Alzheimer's disease (AD).
Methods: Thirty male Sprague-Dawley rats were randomized into 3 groups: Sham, AD, and Tan IIA groups. The AD models were established by injecting Aβ into the hippocampus of rats. Brain tissues were collected and paraffin sections were prepared to assess pathological changes. The expression of p53 and pp53 was detected by immunohistochemical staining and Western blot. Apoptosis was detected by TUNEL assay.
Results: There was no Aβ staining in the sham group, and the difference of Aβ staining between the AD group and the Tan IIA group was not significant (P>0.05). The expressions of p53 and pp53 were significantly higher in the AD group than those in the control group (P<0.05). The number of apoptotic cells in the AD group was significantly higher than that in the sham groups (P<0.05). Treatment of Tan IIA for AD rats significantly reduced the numbers of apoptotic cells (P<0.05).
Conclusion: Aβ can increase the expression of p53 and pp53, and the number of apoptotic cells. Tan IIA treatment may inhibit apoptosis by down-regulation of p53 and pp53 in rats, and in turn to protect neurons.
目的：观察丹参酮IIA(tanshinone IIA，Tan IIA)对β-淀粉样蛋白(Aβ)诱导的阿尔茨海默病(Alzheimer’s disease，AD)模型大鼠脑组织中p53与磷酸化p53(phosphate p53，pp53)表达以及细胞凋亡的影响。方法：将30只雄性SD大鼠随机分为假手术组、AD模型组和Tan IIA治疗组。在大鼠海马内注射Aβ建立AD动物模型，采用免疫组织化学法和Western印迹检测AD大鼠脑组织p53与pp53的表达水平，TUNEL法检测大鼠脑组织中的细胞凋亡。结果：Aβ在假手术组中无表达；而在AD模型组和Tan IIA治疗组均有表达且两组间差异无统计学意义(P>0.05)，证明AD模型建造成功。AD模型组p53与pp53的表达水平明显高于假手术组(P<0.05)和Tan IIA治疗组(P<0.05)。AD模型组凋亡细胞数显著多于假手术组(P<0.05)和Tan IIA治疗组(P<0.05)。结论：Aβ引起脑组织p53与pp53的表达明显增高，凋亡细胞增多；Tan IIA可能是通过降低大鼠p53与pp53的表达而抑制细胞的凋亡，从而起到神经保护作用。.