【摘要】 目的探讨限时摄食可通过升高β羟基丁酸(βOHB)水平而抑制组蛋白去乙酰化酶(HDACs),进而调节α-互养蛋白(SNTA1)表达,改善阿尔兹海默病(AD)模型小鼠脑中水通道蛋白-4(AQP4)极性分布。方法将5月龄APPswe/PS1dE9双转基因小鼠分为AD模型组、AD禁食组,同窝出生的野生型C57/BL6小鼠分为野生对照组、野生禁食组,每组10只,雌雄各半;禁食组小鼠隔日禁食,AD模型组与野生对照组小鼠自由摄食,连续处理5月;采用免疫荧光双标法检测大脑皮质AQP4极性分布情况,qRT-PCR和Westernblotting法检测大脑皮质SNTA1、HDAC1/2mRNA及蛋白表达水平。以终浓度为1mmol/LβOHB预处理人星形胶质细胞瘤(U251)细胞,再以终浓度为2、10μmol/L的β-淀粉样蛋白(Aβ)进行处理,同时设立对照组;此外,以siRNA方法沉默U251细胞HDAC1/2基因,并设立对照组;qRT-PCR和Western blotting法检测细胞SNTA1、HDAC1/2 mRNA及蛋白表达水平。结果限时摄食可改善AD模型小鼠大脑皮质AQP4极性分布的丧失,并可抑制AD模型小鼠大脑皮质SNTA1的降低和HDAC1/2的升高(P<0.01)。βOHB可抑制2、10μmol/L Aβ诱导的U251细胞SNTA1的降低和HDAC1/2的升高(P<0.05或P<0.01)。沉默HDAC1可上调U251细胞SNTA1mRNA和蛋白表达(P<0.01),而沉默HDAC2后SNTA1表达则未见改变。结论βOHB可通过抑制HDAC1表达,介导限时摄食拮抗AD模型小鼠大脑皮质SNTA1表达的降低,从而恢复AQP4的极性分布。[营养学报,2019,41(6):580-586]更多还原

【Abstract】 Objective To investigate the inhibitory effect of time-limited feeding on histone deacetylase(HDACs) by increasing the level of β-hydroxybutyric acid(βOHB), thereby regulating α-mutant protein(SNTA1) and improving aquaporin-4(AQP4) polarity distribution in the cerebral cortex of Alzheimer’s disease(AD) model mice. Methods The APPswe/PS1 dE9 double transgenic mice were divided into the AD model group and AD fasting group while wildtype littermates C57/BL6 mice were divided into the wild control group and wild fasting group. Each group had five males and five females. Mice in fasting group were fed ad libitum every other day and fasted the following day, while mice in the AD model and wild control groups were fed ad libitum for 5 months. Immunofluorescence was performed for AQP4 and CD31 staining to examine AQP4 distribution, qRT-PCR and Western-blot were used respectively to measure the mRNA and protein expressions of SNTA1 and HDAC1/2 in the cerebral cortex of mice. Human U251 gliomia cells were cultured for 3 h with βOHB at a final concentration of 1 mmol/L before being treated with Aβ(at a final concentration of 2, 10 μmol/L) for an additional 12 h. Small interfering RNA was used to silence HDAC1 or HDAC2 expressions. qRT-PCR and Western-blot were separately used to measure the mRNA and protein expression levels of SNTA1 andHDAC1/2 in U251 cells. Results Time-limited feeding inhibited the loss of AQP4 polarity distribution,the decrease of SNTA1 expression and the increase of HDAC1/2 expression in the cerebral cortex of model mice(P< 0.01). βOHB inhibited the decrease of SNTA1 expression and the increase of HDAC1/2 expression in 2 or 10 μmol/L Aβ-exposed U251 cells(P<0.05 or P<0.01). The expression of SNTA1 was increased in HDAC1 silenced U251 cells compared with the control(P<0.01). However, no difference in SNTA1 expressions was found between HDAC2 silenced cells and the control(P > 0.05).ConclusionβOHB may mediate the effect of time-limited feeding on the increase of SNTA1 in the cerebral cortex AD model mice by inhibiting HDAC1, resulting in restoring the polarity distribution of AQP4. [ACTA NUTRIMENTA SINICA, 2019, 41(6):580-586]更多还原