Moghazy Hoda M, Abdelhaliem Nesreen G, Mohammed Sherine Ahmed, Hassan Asmaa, Abdelrahman Amany
Department of Physiology, Faculty of Medicine, Sohag University, Sohag, 82524, Egypt.
Department of Histology, Faculty of Medicine, Sohag University, Sohag, Egypt.
Pflugers Arch. 2024 May;476(5):779-795. doi: 10.1007/s00424-024-02933-0. Epub 2024 Mar 27.
The American Diabetes Association guidelines (2021) confirmed the importance of raising public awareness of diabetes-induced cognitive impairment, highlighting the links between poor glycemic control and cognitive impairment. The characteristic brain lesions of cognitive dysfunction are neurofibrillary tangles (NFT) and senile plaques formed of amyloid-β deposition, glycogen synthase kinase 3 beta (GSK3β), and highly homologous kinase tau tubulin kinase 1 (TTBK1) can phosphorylate Tau proteins at different sites, overexpression of these enzymes produces extensive phosphorylation of Tau proteins making them insoluble and enhance NFT formation, which impairs cognitive functions. The current study aimed to investigate the potential contribution of liraglutide and pramlintide in the prevention of diabetes-induced cognitive dysfunction and their effect on the PI3K/AKT/GSK-3β/TTBK1 pathway in type 2 diabetic (T2D) rat model. T2D was induced by administration of a high-fat diet for 10 weeks, then injection of a single dose of streptozotocin (STZ); treatment was started with either pramlintide (200 μg/kg/day sc) or liraglutide (0.6 mg/kg/day sc) for 6 weeks in addition to the HFD. At the end of the study, cognitive functions were assessed by novel object recognition and T-maze tests. Then, rats were sacrificed for biochemical and histological assessment of the hippocampal tissue. Both pramlintide and liraglutide treatment revealed equally adequate control of diabetes, prevented the decline in memory function, and increased PI3K/AKT expression while decreasing GSK-3β/TTBK1 expression; however, liraglutide significantly decreased the number of Tau positive cells better than pramlintide did. This study confirmed that pramlintide and liraglutide are promising antidiabetic medications that could prevent associated cognitive disorders in different mechanisms.
美国糖尿病协会指南(2021年)证实了提高公众对糖尿病所致认知障碍认识的重要性,强调了血糖控制不佳与认知障碍之间的联系。认知功能障碍的典型脑损伤是神经原纤维缠结(NFT)以及由β淀粉样蛋白沉积形成的老年斑,糖原合酶激酶3β(GSK3β)和高度同源的激酶微管相关蛋白tau激酶1(TTBK1)可在不同位点使Tau蛋白磷酸化,这些酶的过表达会使Tau蛋白产生广泛磷酸化,使其不溶并增强NFT形成,从而损害认知功能。本研究旨在探讨利拉鲁肽和普兰林肽在预防糖尿病所致认知功能障碍中的潜在作用及其对2型糖尿病(T2D)大鼠模型中PI3K/AKT/GSK-3β/TTBK1信号通路的影响。通过给予10周高脂饮食,然后单次注射链脲佐菌素(STZ)诱导T2D;除高脂饮食外,用普兰林肽(200μg/kg/天,皮下注射)或利拉鲁肽(0.6mg/kg/天,皮下注射)开始治疗6周。在研究结束时,通过新物体识别和T迷宫试验评估认知功能。然后,处死大鼠以对海马组织进行生化和组织学评估。普兰林肽和利拉鲁肽治疗均显示对糖尿病有同等充分的控制,预防了记忆功能下降,并增加了PI3K/AKT表达,同时降低了GSK-3β/TTBK1表达;然而,利拉鲁肽比普兰林肽更显著地减少了Tau阳性细胞数量。本研究证实,普兰林肽和利拉鲁肽是有前景的抗糖尿病药物,可通过不同机制预防相关认知障碍。