Electroacupuncture inhibits hippocampal neuronal apoptosis and improves cognitive dysfunction in mice with vascular dementia via modulating JNK signaling pathway

Abstract

Background: Nerve cell apoptosis is an important pathological mechanism of vascular dementia (VaD). There are evidences that Electroacupuncture (EA) can reduce cognitive impairment in VaD patients and protect nerve cells. However, the mechanism remains unknown. JNK signaling pathway play an important role in apoptosis. And JNK induces cell apoptosis in two main ways, namely JNK transcription-dependent pathway and JNK transcription-independent route. We focus on whether EA can inhibit apoptosis and alleviate cognitive impairment by regulating JNK signaling pathway.Method: In this study, Bilateral common carotid artery clipping (BCCAo) was used as a method to establish VaD mouse model. Longa scoring method and Morris water maze were used to evaluate whether EA could improve the behavioral score of VaD mice. The neuroprotective effects of EA were evaluated by the Hematoxylin and Eosin (HE) staining, TUNEL and Flow Cytometry (FCM). Western blot and real-time PCR were used to detect the expression of JNK-3, AP-1, P53, Bcl -2, Bax, and Caspase-3.Results: Our findings indicated that EA could improve the behavioral scores of VaD mice. VaD mice treated with EA reduced hippocampal neuronal apoptosis. In addition, EA could reduce the expression of JNK-3, AP-1, P53, Bax and Caspase-3 proteins and mRNA in the hippocampus of VaD mice, and increase the expression of Bcl-2.Conclusion: Our findings suggested that the mechanism of action of EA to treat VaD may be related to its regulation of JNK transcription-dependent pathway and JNK transcription-independent route.