Wang Yuan, Wang Qiang, Luo Di, Zhao Pu, Zhong Sha-Sha, Dai Biao, Wang Jia-Jyu, Wan Yi-Tong, Liu Zhi-Bin, Yang Huan
College of Acu-moxibustion and Massage, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, 712046, China.
Department of Traditional Chinese Medicine, Baotou Medical College, Baotou, Inner Mongolia Autonomous Region, 014040, China.
Chin J Integr Med. 2023 May;29(5):448-458. doi: 10.1007/s11655-023-3592-5. Epub 2023 Jan 7.
To investigate the molecular mechanisms underlying the beneficial effect of electroacupuncture (EA) in experimental models of Alzheimer's disease (AD) in vivo.
Senescence-accelerated mouse prone 8 (SAMP8) mice were used as AD models and received EA at Yingxiang (LI 20, bilateral) and Yintang (GV 29) points for 20 days. For certain experiments, SAMP8 mice were injected intravenously with human fibrin (2 mg). The Morris water maze test was used to assess cognitive and memory abilities. The changes of tight junctions of blood-brain barrier (BBB) in mice were observed by transmission electron microscope. The expressions of fibrin, amyloid- β (Aβ), and ionized calcium-binding adapter molecule 1 (IBa-1) in mouse hippocampus (CA1/CA3) were detected by reverse transcription-quantitative polymerase chain reaction (qRT-PCR), Western blot or immunohistochemical staining. The expression of fibrin in mouse plasma was detected by enzyme-linked immunosorbent assay. The expressions of tight junction proteins zonula occludens-1 and claudin-5 in hippocampus were detected by qRT-PCR and immunofluorescence staining. Apoptosis of hippocampal neurons was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining.
Fibrin was time-dependently deposited in the hippocampus of SAMP8 mice and this was inhibited by EA treatment (P<0.05 or P<0.01). Furthermore, EA treatment suppressed the accumulation of Aβ in the hippocampus of SAMP8 mice (P<0.01), which was reversed by fibrin injection (P<0.05 or P<0.01). EA improved SAMP8 mice cognitive impairment and BBB permeability (P<0.05 or P<0.01). Moreover, EA decreased reactive oxygen species levels and neuroinflammation in the hippocampus of SAMP8 mice, which was reversed by fibrin injection (P<0.05 or P<0.01). Mechanistically, EA inhibited the promoting effect of fibrin on the high mobility group box protein 1 (HMGB1)/toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nicotinamide adenine dinucleotide phosphate (NADPH) signaling pathways (P<0.01).
EA may potentially improve cognitive impairment in AD via inhibition of fibrin/A β deposition and deactivation of the HMGB1/TLR4 and RAGE/NADPH signaling pathways.
探讨电针（EA）对阿尔茨海默病（AD）体内实验模型有益作用的分子机制。
将快速老化痴呆模型小鼠8（SAMP8）作为AD模型，针刺迎香（双侧LI 20）和印堂（GV 29）穴，连续治疗20天。在某些实验中，给SAMP8小鼠静脉注射人纤维蛋白（2 mg）。采用Morris水迷宫试验评估认知和记忆能力。通过透射电子显微镜观察小鼠血脑屏障（BBB）紧密连接的变化。采用逆转录-定量聚合酶链反应（qRT-PCR）、蛋白质免疫印迹法或免疫组织化学染色检测小鼠海马体（CA1/CA3）中纤维蛋白、淀粉样β蛋白（Aβ）和离子钙结合衔接分子1（Iba-1）的表达。采用酶联免疫吸附测定法检测小鼠血浆中纤维蛋白的表达。采用qRT-PCR和免疫荧光染色检测海马体中紧密连接蛋白闭合蛋白-1和克劳丁-5的表达。采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）染色检测海马神经元凋亡。
纤维蛋白在SAMP8小鼠海马体中呈时间依赖性沉积，电针治疗可抑制这种沉积（P<0.05或P<0.01）。此外，电针治疗可抑制SAMP8小鼠海马体中Aβ的积累（P<0.01），而纤维蛋白注射可逆转这种抑制作用（P<0.05或P<0.01）。电针改善了SAMP8小鼠的认知障碍和血脑屏障通透性（P<0.05或P<0.01）。此外，电针降低了SAMP8小鼠海马体中的活性氧水平和神经炎症，而纤维蛋白注射可逆转这种作用（P<0.05或P<0.01）。机制上，电针抑制了纤维蛋白对高迁移率族蛋白B1（HMGB1）/Toll样受体4（TLR4）和晚期糖基化终末产物受体（RAGE）/烟酰胺腺嘌呤二核苷酸磷酸（NADPH）信号通路的促进作用（P<0.01）。
电针可能通过抑制纤维蛋白/Aβ沉积以及HMGB1/TLR4和RAGE/NADPH信号通路失活来改善AD的认知障碍。
