基于Galectin-3/C/EBPβ/δ-Secretase信号通路探讨钩藤碱抗阿尔茨海默病的作用及机制
批准号:
82104414
项目类别:
青年科学基金项目(C类)
资助金额:
30.0 万元
负责人:
冼彦芳
依托单位:
学科分类:
中药神经精神药理
结题年份:
2024
批准年份:
2021
项目状态:
已结题
项目参与者:
冼彦芳
中文摘要
钩藤是以“钩藤散”为代表的众多中医临床用以治疗阿尔茨海默病(AD)有效方剂的重要组成药味,钩藤碱是其主要有效成分,但其抗AD作用鲜有报道。本课题组前期研究发现,钩藤碱能显著改善3×Tg-AD小鼠的认知障碍,抑制Aβ沉积、炎症反应、tau蛋白磷酸化、Galectin-3及p-C/EBPβ的蛋白表达,但具体分子机制尚不明。基于Galectin-3/C/EBPβ/δ-Secretase通路介导的神经炎症、淀粉样斑块形成、tau蛋白磷酸化在AD发生发展中扮演重要角色,提出“钩藤碱可能通过调节Galectin-3/C/EBPβ/δ-Secretase通路发挥抗AD作用”的假说。拟采用3×Tg-AD转基因小鼠及BV-2细胞,结合慢病毒转染介导的基因沉默技术,评估钩藤碱抗AD的作用,阐明钩藤碱对Galectin-3/C/EBPβ/δ-Secretase通路的调控机制,为中医药防治AD提供新思路和视角。
英文摘要
Gouteng (Uncariae Ramulus Cum Uncis) is one of the frequently prescribed Chinese herb for the treatment of Alzheimer’s disease (AD) in Chinese medicine practice. Our recent studies have revealed that rhynchophylline (RN) possesses potent anti-AD activities. RN could significantly improve the cognitive deficits, decrease the protein levels of beta amyloid (Aβ)40 and Aβ42, and suppress the phosphrylated tau protein, Galectin-3, PPARγ, phosphrylated C/EBPβ protein expressions of the brain tissues of 3×Tg-AD transgenic mice. However, its detailed mechanism of action remains obscure. Galectin-3/C/EBPβ/δ-Secretase pathway plays a critical role in cognitive impairment, neuroinflammation, formation of senile plaques and tau protein hyperphosphrylation. Based on these promising findings, we hypothesize that RN exerts anti-AD effect via modulation of the Galectin-3/C/EBPβ/δ-Secretase signaling pathway. To present evidence to support the novel hypothesis, 3×Tg-AD transgenic mice, BV-2 microglia cells and behavior tests such as a novel object recognition test, a fear conditioning test and a Morris water maze test, and the techniques such as ELISA kits, western blot, RT-PCR, immunohistochemistry, and lentiviral transfection will be applied to explore the cognitive deficits ameliorating effects of RN in 3×Tg-AD transgenic mice and its molecular mechanisms. We anticipate that the present study would likely elucidate the molecular mechanism underlying the anti-AD effect of RN, and lay a foundation for development of RN as an effective pharmacological therapeutic for clinical treatment of AD in future.
阿尔茨海默病(Alzheimer's disease, AD)严重影响人类健康。钩藤是以“钩藤散”为代表的众多中医临床用以治疗阿尔茨海默病(AD)有效方剂的重要组成药味,钩藤碱(rhynchophylline, RN)是其主要有效成分,但其抗AD作用鲜有报道。本研究拟采用 6月龄雌性3×Tg-AD 转基因小鼠模型,灌胃给与钩藤碱(20, 40 和 80 g/kg)六个月,给药结束后,采用矿场试验、新物体识别试验和水迷宫试验进一步明确 RN 抗AD 的生物活性及其作用机理。结果表明,钩藤碱能显著改善3×Tg-AD 转基因小鼠的认知障碍和焦虑养行为,明显抑制小鼠脑组织IL-6, IL-1β, and TNF-α的水平,及皮层和海马小胶质细胞(Iba-1)、星型胶质(GFAP)细胞的数量和Aβ斑块的沉积。同时,钩藤碱能显著抑制β-分泌酶(BACE1和p-APP(T668)),γ-分泌酶(APH-1) 和δ-分泌酶 (FL-APP)的活性,但提高β-淀粉样降解酶的活性(IDE)。此外,钩藤碱显著减低3×Tg-AD转基因小鼠海马组织中tau蛋白在Thr181、Thr205 和Ser404位点的磷酸化。重要的是,钩藤碱能显著抑制3×Tg-AD转基因小鼠脑组织中Galectin-3, C/EBPβ和AEP蛋白的表达。此外,Galectin-3 基因沉默和钩藤碱均能显著的抑制由Aβ诱导的BV-2 细胞中促炎因子IL-6, IL-1β, 和 TNF-α的释放。更重要的是,钩藤碱干预明显增强Galectin-3 基因沉默抑制Aβ诱导的BV-2 细胞中促炎因子IL-6, IL-1β, 和 TNF-α的释放,。以上研究结果表明,钩藤碱通过抑制Galectin-3/C/EBPβ/δ-Secretase 信号通路的活化,从而抑制神经炎症和Aβ的沉积,发挥抗阿尔茨海默病的作用。本研究结果为钩藤碱抗阿尔茨海默病的作用及其机制提供科学依据,也为中药抗AD的研究提供新的思路和视角。
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