Progress of researches on acupuncture treatment of cerebral ischemia-reperfusion injury by regulating autophagy in the ischemic cerebral tissue

Abstract

Excessive autophagy is one of the crucial factors of cerebral ischemia-reperfusion injury (CIRI), which has been demonstrated to be one of the targets for acupuncture treatment of ischemic stroke. In the present paper, we make a review about the development of acupuncture intervention induced improvement of CIRI (such as reducing the infarction area, improving learning-memory ability and motor function) by regulating autophagy in animal studies. Outcomes showed that acupuncture intervention can function in 1) inhibiting CIRI-induced increase of the number of lysosomes and autophagic lysosomes, and relieving structural injury of mitochondria, and reducing the number of autophagosome in the central region of the ischemic cerebral cortex tissue; 2) down-regulating the expression of microtubule-associated protein Ⅱ light chain 3 (LC3Ⅱ) and the ratio of LC3-Ⅱ/LC3-Ⅰ in the ischemic cerebral region, and 3) regulating the expression of Beclin 1 (autophagy-related gene), promoting the expression of P62 (autophagy-related adaptor protein). In addition, acupuncture can also regulate phosphoinositide 3 kinase (PI3K)- protein kinase B (AKT)- mammalian target of rapamycin complex 1(mTOR) signaling at different time-points (down-regulation at the early stage and up-regulation at the later stage), and activating AMP-activated protein kinase (AMPK)-mTOR- UNC51-like kinase-1 signaling to relieve cerebral ischemic injury. These results reveal some mechanisms of acupuncture therapy underlying improvement of CIRI and provide experimental basis for clinical application of acupuncture therapy in the treatment of ischemic stroke.