High-frequency repetitive transcranial magnetic stimulation protects against cerebral ischemia/reperfusion injury in rats: Involving the mitigation of ferroptosis and inflammation.

BACKGROUND AND AIM: Repetitive transcranial magnetic stimulation (rTMS) has been found to attenuate cerebral ischemia/reperfusion (I/R) injury. However, its effects and mechanism of action have not yet been clarified. It has been reported that cerebral I/R injury is closely associated not only with ferroptosis but also with inflammation. Hence, the current study aimed to investigate whether high-frequency rTMS attenuates middle cerebral artery occlusion (MCAO)-induced cerebral I/R injury and further to elucidate the mediatory role of ferroptosis and inflammation. METHODS: The protective effects of rTMS on experimental cerebral I/R injury were investigated using transient MCAO model rats. Neurological scores and pathological changes of cerebral ischemic cortex were assessed to evaluate the effects of rTMS on cerebral I/R injury. The involvement of ferroptosis and that of inflammation were examined to investigate the mechanism underlying the effects of rTMS. RESULTS: High-frequency rTMS remarkably rescued the MCAO-induced neurological deficits and morphological damage. rTMS treatment also increased the mRNA and protein expression of glutathione-dependent peroxidase 4, decreased the mRNA and protein levels of acyl-CoA synthetase long-chain family member 4 and transferrin receptor in the cortex. Moreover, rTMS administration reduced the cerebrospinal fluid IL-1ß, IL-6, and TNF-α concentrations. CONCLUSION: These findings implicated that high-frequency rTMS alleviates MCAO-induced cerebral I/R injury, and the underlying mechanism could involve the inhibition of ferroptosis and inflammation. Our study identifies rTMS as a promising therapeutic agent for the treatment of cerebral I/R injury. Moreover, the mechanistic insights into ferroptosis and inflammation advance our understanding of it as a potential therapeutic target for diseases beyond cerebral ischemia stroke.

[Effect of electroacupuncture at "Shuigou" (GV26) and "Baihui" (GV20) on autophagy of hippo-campal neurons in rats with cerebral ischemia-reperfusion injury].

OBJECTIVE: To explore the effect of electroacupuncture (EA) at "Shuigou"(GV6) and "Baihui"(GV20) on autophagy of hippocampal neurons in cerebral ischemia-reperfusion (I/R) injury rats. METHODS: Forty-eight healthy male SD rats were randomly divided into sham operation, model and EA groups, with 16 rats in each group. The rat model of cerebral I/R injury was established by occlusion of the middle cerebral artery (MCAO). Rats of the EA group received EA at GV26 and GV20 for 20 min, once daily for 5 days. The neurological function of rats in each group was evaluated by Longa neurological function score. The cerebral infarction volume was measured by TTC staining. The levels of IL-6, IL-18 and TNF-α in cerebrospinal fluid were detected by ELISA. Real-time PCR and Western blot were respectively used to detect the expressions of autophagy-related proteins AMPK, Beclin-1, VPS34 and LC3B. RESULTS: Compared with the sham operation group, neurological function scores of rats in the model group were significantly increased (P<0.01); the volume of cerebral infarction was significantly increased (P<0.01); the contents of IL-6, IL-18 and TNF-α in cerebrospinal fluid were increased (P<0.01, P<0.05); the mRNA expression levels of AMPK, Beclin-1, VPS34 and LC3B were significantly increased (P<0.01); the protein expressions of AMPK, Beclin-1, VPS34 and the ratio of LC3B-Ⅱ/LC3B-Ⅰ were increased (P<0.01, P<0.05). After intervention and in comparison with the model group, the neurological function scores were decreased (P<0.05); the cerebral infarct volume were decreased (P<0.05); the contents of IL-6, IL-18 and TNF-α in cerebrospinal fluid were decreased (P<0.05); the mRNA expressions of AMPK, Beclin-1, VPS34 and LC3B were significantly decreased (P<0.01); the protein expressions of AMPK, Beclin-1, VPS34 and the ratio of LC3B-Ⅱ/LC3B-Ⅰ were decreased (P<0.05, P<0.01). CONCLUSION: EA can improve the neurological function and alleviate the degree of nerve injury in rats with cerebral I/R injury, which may be related to inhibiting the autophagy level of hippocampal neurons.