Effects of electro-acupuncture on Noxa and caspase-3 expression in hippocampal CA1 region of a vascular dementia rat model

Yanzhen Zhu; Qiang Wu; Ling Lin

摘要：BACKGROUND: Noxa, a pro-apoptotic member of the Bcl-2 protein family, has been shown to induce the mitochondrial pathway of apoptosis and to mediate hypoxic cell death in a rat model of cerebral ischcmia.This suggests that Noxa could participate in apoptosis during vascular dementia (VD).OBJECTIVE,: To detect Noxa and caspase-3 expression after electro-acupuncture in VD rats to further validate the mechanism of electro-acupuncture-induced effects in the treatment of VD.DESIGN, TIME AND SETTING: A randomized, controlled study was performed at the Center for the Neurobiology of Fujian Medical University between January 2006 and March 2007.MATERIALS: A total of forty adult, male, Sprague Dawley rats were included in this study. The following equipment was used: confocal laser scanning microscope (SpS, Leica, Germany), water matte (Bejing Suntendy Science and Technology Co., Ltd., China), and SDZ-Ⅱ electronic acupuncture treatment instruments (Suzhou Medical Appliance Factory, China).METHODS: Thirty-eight rats with sufficient learning and memory abilities were selected by Morris water maze criteria. Twelve rats received sham-surgery; the remaining 26 rats were used to establish a VD model by bilateral occlusion of the common carotid arteries. The rats that survived the occlusion procedure were randomly assigned into an electro-acupuncture group (n = 11) and a VD model group (n = 12).MAIN OUTCOME MEASURES: Neuropathological changes were observed with hematoxylin-eosin staining of the hippocampus and expression of Noxa and caspasc-3 in the hippocampal CAI region was analyzed by confocal laser scanning microscope following immunofluorescence staining.RESULTS: Expressions of Noxa and caspase-3 in the electro-acupuncture group and sham-operated group were less than in the VD model group (P < 0.01). Electro-acupuncture reduced the amount of apoptotic neurons in hippocampal CA1 area of rats with VD. The average latency in the Morris water maze test was significantly shorter, and escape strategies improved from edge and random searches to more linear swim pathways in the electro-acupuncture group compared with the VD model group (P < 0.01).CONCLUSION: Electro-acupuncture can improve learning and memory ability and inhibit the occurrence of apoptosis by blocking expression of Noxa and caspase-3 in the hippocampal CA1 region of VD rats.