轻度认知障碍及阿尔茨海默病患者外周血淋巴细胞中蛋白磷酸酯酶-2A的改变

Alterations of protein phosphatase-2A in peripheral lymphocytes in mild cognition impairment and Alzheimer's disease

目的探讨轻度认知功能障碍(MCI)及阿尔茨海默病(AD)患者外周血淋巴细胞蛋白磷酸酯酶-2A(PP-2A)的变化。方法用放射性配体结合试验检测11名健康对照者、11例 MCI 患者及11例 AD 患者外周血淋巴细胞 PP-2A 的活性,并用 Western blot 检测 PP-2A 蛋白的表达。结果 MCI 组外周血淋巴细胞 PP-2A 活性(0.71±0.12)及蛋白表达(0.80±0.05)与健康对照组[分别为(1.01±0.09)和(0.96±0.07)]相比明显降低(均 P<0.01);AD 组 PP-2A 活性(0.64±0.11)及蛋白表达-(0.76+0.06)亦明显降低,与对照组相比差异有统计学意义(均 P<0.01);AD 组 PP-2A 活性及蛋白表达比 MCI 组有降低的趋势,但差异无统计学意义。结论 MCI 及 AD 患者外周血淋巴细胞 PP-2A 的活性及表达降低,在 MCI 的诊断中可能有参考价值,同时亦可能对 AD 的诊断有一定的潜在的意义。

Objective To explore the alterations of protein phosphatase-2A （PP-2A） in lymphocytes in mild cognition impairment （MCI） and Alzheimer＇ s disease （AD）. Methods The activity PP-2A of was measured by 32p liquid seintillography for incorporated radioactivity in control group（ n = 11 ）, the MCI group（n = 11 ）, and the AD group（n = 11 ）. The expression of PP-2A was determined by Western blot. Results In the control group, the activity of PP-2A （ 1.01 ± 0. 09） and the expression of PP-2A （0. 96 ±0. 07） were high while in the MCI group, the activity of PP-2A （0. 71 ±0. 12） and the expression of PP-2A （0. 80 ± 0. 05 ） were decreased （ both P 〈 0. 01 ）, the activity of PP-2A （0. 64 ± 0. 11 ） and the expression of PP-2A （0. 76 ± 0. 06） were also decreased （both P 〈 0. 01 ）in the AD group compared with control group. Conclusion Low levels of activity and expression of PP-2A, which implies a diagnosis in MCI and AD, are induced in lymphoeytes.