| 摘要: |
| 目的探讨生酮饮食（KD）对戊四氮（PTZ）点燃大鼠海马损伤及哺乳动物雷帕霉素钯蛋白（mTOR）通路表达的作用机制。方法将55只雄性SD大鼠隔日腹腔注射PTZ制作癫痫动物模型直至完全点燃，另5只大鼠（空白对照组）腹腔注射0.9%氯化钠溶液。完全点燃后的44只大鼠随机分成4组，即正常食物（ND）+PTZ组、ND+PTZ+雷帕霉素（RAP）组、KD+PTZ组、KD+PTZ+RAP组，每组11只，均予侧脑室置管并再次给予隔日腹腔注射PTZ，共5次；其中ND+PTZ+RAP组、KD+PTZ+RAP组给药前30min侧脑室注射RAP，ND+PTZ组、KD+PTZ组予以等量人工脑脊液。观察并比较5组大鼠癫痫发作等级，海马区神经元密度，海马区pS6、S6、pAkt、Akt、pAMPK、AMPK的表达（采用Westernblot法检测）。结果KD+PTZ组大鼠癫痫发作等级明显低于ND+PTZ组（P＜0.01）；KD+PTZ+RAP组发作等级明显低于ND+PTZ组及ND+PTZ+RAP组（均P＜0.05）。海马CA1区神经元密度：KD+PTZ组明显大于ND+PTZ组（P＜0.05），KD+PTZ+RAP组大于ND+PTZ+RAP组（P＜0.05），ND+PTZ+RAP组大于ND+PTZ组（P＜0.05）。与空白对照组相比，ND+PTZ组pS6/S6、pAkt/Akt蛋白表达增加（均P＜0.05），其余4组pAMPK/AMPK蛋白表达均增高（均P＜0.05）；与ND+PTZ组相比，KD+PTZ组pS6/S6、pAkt/Ak蛋白表达均降低（均P＜0.05），pAMPK/AMPK蛋白表达增高（P＜0.05）；与ND+PTZ组相比，ND+PTZ+RAP组pS6/S6、pAkt/Akt蛋白表达均明显降低（均P＜0.05）；与KD+PTZ组相比，KD+PTZ+RAP组pS6/S6、pAkt/Akt蛋白表达明显降低（均P＜0.05）；与ND+PTZ+RAP组相比，KD+PTZ+RAP组pS6/S6蛋白表达明显下降（P＜0.05），pAMPK/AMPK增高（P＜0.05）。结论KD具有抗癫痫发作、减少神经元丢失的作用，这种保护作用可能与其对mTOR通路的抑制有关，且其上游可能通过抑制Akt通路的磷酸化、激活AMPK通路的磷酸化来调节mTOR通路。 |
| 关键词: 生酮饮食 哺乳动物雷帕霉素钯蛋白信号通路 癫痫 海马 神经保护 |
| DOI：10.12056/j.issn.1006-2785.2017.39.12.2016-1784 |
| 分类号: |
| 基金项目:国家自然科学基金项目（81301113、81302938）；浙江省自然科学基金项目（LY16H270002） |
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| Ketogenic diet attenuates hippocampus injury in pentylenetetrazol-kindled seizure and its relation to mammalian target of rapamycin pathway suppression in rats |
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JIANG Yan, WANG Baohui, JIA Mengmeng, LU Yuqiang, QIU Tao, ZHANG Zhengxiang, HOU Qun
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Zhejiang Hospital of Traditional Chinese Medicine
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| Abstract: |
| Objective To investigate the effect of ketogenic diet on hippocampus injury in pentylenetetrazol-kindled seizure and its relation to mammalian target of rapamycine (mTOR) pathway in rats. Methods The PTZ-kindled seizure model was induced by intra-ventricular infusion of 35mg/kg pentylenetetrazol (PTZ) in male Sprague-Dawley (SD) rats. Forty four rats, in which the seizure was fully kindled, were divided into 4 groups with 11 rats in each group. Rats in ND+PTZ and ND+PTZ+RAP groups were fed with normal diet, while those in KD+PTZ and KD+PTZ+RAP were fed with ketogenic diet. The mTOR pathway inhibitor rapamycin(RAP) was given to rats in ND+PTZ+RAP and KD+PTZ+RAP groups by intra-ventricular infusion 30min before PTZ injection. The seizure stages and the neuron in hippocampal CA1, CA3 and DG regions were counted. And the expressions of pS6, S6, pAkt, Akt, pAMPK and AMPK were detected by Western blot. Results The seizure stage of the kindled rats in the KD+PTZ group was lower than that of ND+PTZ group significantly (P＜0.05). The stages of KD+PTZ+RAP group were lower than those of ND+PTZ and ND+PTZ+RAP groups significantly (P＜0.05). The density of neuron in hippocampal CA1 subarea in KD+PTZ group was higher than ND+PTZ group significantly (P ＜0.05), and the density of KD+PTZ+RAP was higher than ND+PTZ+RAP group (P＜0.05). Additionally, the density of ND+PTZ+RAP was higher than ND+PTZ (P＜0.05). Western blot result shows that the expression of phosphor-S6 to total S6(pS6/S6) and phosphor-Akt to total Akt(pAkt/Akt) was increased in ND+PTZ
group compared to control (P＜0.05). The expression levels of phosphor-AMPK to total AMPK (pAMPK/AMPK) in all kindled
groups were higher than those of non-kindled control groups (P＜0.05). Compared to the ND+PTZ group, the expression levels of pS6/S6 and pAkt/Akt were decreased (P ＜0.05), while the pAMPK/AMPK was increased in KD+PTZ group (P ＜0.05). Compared to the KD+PTZ group, the expression of pS6/S6 and pAkt/Akt in KD+PTZ+RAP group were decreased (P＜0.05). Similarly, compared to the ND+PTZ group, the expression of pS6/S6 and pAkt/Akt in ND+PTZ+RAP group was also significantly decreased (P ＜0.05). Moreover, compared to ND+PTZ+RAP, the expression level of pS6/S6 in KD+PTZ+RAP group was decreased significantly (P＜0.05), while the expression level of pAMPK/AMPK was increased (P＜0.05). Conclusion Our study
indicated that ketogenic diet has the anti-seizure and neuronal protective effect in PTZ kindled rat model, which may be related to the mTOR pathway suppression. Moreover, the mTOR pathway is modulated by both the inhibition of Akt and activation of AMPK pathway |
| Key words: Ketogenic diet mTOR signaling pathway Seizure Hippocampus Neuroprotection |
