Mechanisms of Tongdu Tiaoshen acupuncture therapy in protecting against cerebral ischemia reperfusion injury☆

Abstract

Objective: To observe the potential mechanisms of Tongdu Tiaoshen (unblocking the governor vessel and regulating the mind) acupuncture therapy in protecting against cerebral ischemia-reperfusion injury (CIRI).

Methods: SD rats were divided into a sham-operated group, a model group, and a Tongdu Tiaoshen acupuncture group (acupuncture group) randomly, with 12 rats in each group. Middle cerebral artery occlusion models were prepared using the Longa suture-occluded method. In the acupuncture group, acupuncture was operated at “Dazhu (GV14)”, “Shenting (GV24)” and “Baihui (GV20)” for 20 min in each intervention, once daily and for 12 consecutive days. In the sham-operated group and the model group, the rats were grasped and fixed for the same duration as those in the acupuncture group, but without acupuncture intervention. The degree of neurological impairment in rats after intervention was assessed using the Zea Longa method. HE staining was employed to observe the pathological changes in the rat cerebral cortex. Western blotting was used to detect the protein expression levels of apoptosis-associated speck-like protein containing a CARD (ASC), pro-caspase-1, and P2 × 7 receptor (P2 × 7R) in the rat cerebral cortex. ELISA was performed to measure the levels of interleukin (IL)-1β and IL-18 in the rat cerebral cortex. Immunofluorescence was utilized to observe the positive expression of ASC, pro-caspase-1, and P2 × 7R in the rat cerebral cortex.

Results: Compared to the sham-operated group, the model group showed the increase in neurological deficit score (P < 0.01), the cells surrounding the ischemic foci were sparse and loosely distributed under the microscope; the protein expression of ASC, pro-caspase-1 and P2 × 7R were elevated (P < 0.01), their positive expression increased; and the levels of IL-1β and IL-18 rose (P < 0.01). Compared to the model group, in the acupuncture group, the neurological deficit score decreased (P < 0.05), and cellular morphological changes were mild around the ischemic foci observed under microscopy; the protein expression of ASC, pro-caspase-1 and P2 × 7R was reduced (P < 0.01) and their positive expression was declined; and the expression of IL-1β and IL-18 decreased (P < 0.01).

Conclusion: The mechanisms of Tongdu Tiaoshen acupuncture in protecting against CIRI may be associated with down-regulating the expression of P2 × 7R and attenuating inflammatory response.