6-Shogaol Alleviates Post-Cardiopulmonary Resuscitation Brain Injury in Rats by Regulating the miRNA-26a-5p/DAPK1

This study aims to investigate the neuroprotective effect of 6-shogaol (6-SH) in rats after cardiopulmonary resuscitation (CPR), and to explore the molecular mechanism by which it regulates the miRNA-26a-5p/DAPK1 to inhibit excessive Autophagy and calcium overload. A rat model of cerebral ischemia-reperfusion injury after cardiac arrest and CPR was established by asphyxia. Sham, CPR, and CPR + 6-SH groups were set up. DAPK1 overexpression and miRNA-26a-5p inhibition were also performed. Neurological function was evaluated using the Neurological Deficit Score (NDS). Hematoxylin-eosin staining was used to assess pathological damage in brain tissue. Immunofluorescence was used to observe the expression of Autophagy markers. Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot (WB) were used to detect the expression of autophagy- and calcium overload-related genes and proteins. A dual-luciferase reporter assay was conducted to verify the targeting relationship between miRNA-26a-5p and DAPK1. Molecular docking was used to analyze the binding interaction between 6-SH and miRNA-26a-5p. The results show that 6-SH significantly reduces brain injury and improves neurological function after CPR. It decreases the expression of autophagy-related proteins (Vps34, Beclin1, LC3) and the calcium overload marker (NMDAR2B). Further mechanistic studies show that 6-SH inhibits DAPK1 expression and attenuates excessive Autophagy and calcium overload. In addition, 6-SH binds to miRNA-26a-5p and upregulates its expression, which in turn suppresses DAPK1. When miRNA-26a-5p is inhibited, the effects of 6-SH on DAPK1, Autophagy, and calcium overload are partially reversed. In conclusion, 6-SH attenuates brain injury after CPR by regulating the miRNA-26a-5p/DAPK1 to suppress excessive Autophagy and calcium overload.