Electro-acupuncture Suppresses Ferroptosis to Alleviate Cerebral Ischemia-Reperfusion Injury Through KAT3B-Mediated Succinylation of ACSL4.

Abstract

Electro-acupuncture (EA) is identified as an effective therapeutic method for cerebral ischemia/reperfusion injury (CIRI), which is a combination of Chinese traditional acupuncture and modern electro-therapy. However, the downstream molecular mechanisms of EA in CIRI process remains largely unknown. The purpose of the present study is to unveil the therapeutic effect of EA on CIRI rat and its regulatory mechanisms. At first, we constructed middle cerebral artery occlusion (MCAO) rat models and then treated them with EA to observe the pathological changes. The results indicated that EA decreased the infarct volume (43.81 ± 3.34 vs 15.96 ± 2.22) and the neurological scores (3.33 ± 0.52 vs 1.67 ± 0.52) and suppressed the apoptosis in MCAO model rats. For ferroptosis analysis, EA decreased the Fe2 + (0.08 ± 0.01 vs 0.06 ± 0.01), MDA (36.61 ± 4.29 vs 21.72 ± 2.79), and LPS (5.25 ± 0.69 vs 2.89 ± 0.42) contents and increased the GSH (4.94 ± 1.04 vs 11.69 ± 1.88) content in MCAO model rats. We next detected whether succinylation mediated EA-treated I/R injury. According to immunoprecipitation and western blot analysis, EA treatment could lower both levels of succinylation and KAT3B in MCAO rats. Moreover, mechanism experiments unveiled that KAT3B promoted the succinylation of the ferroptosis-related protein ACSL4 at K661 site and thus stabilizing ACSL4. Finally, EA-treated MCAO rats were further injected with KAT3B expression vector. The results showed that KAT3B overexpression increased the infarct volume (31.44 ± 3.92 vs 7.94 ± 2.84) and the neurological scores (2.67 ± 0.51 vs 1.33 ± 0.51) and promoted the apoptosis in EA treated MCAO model rats. For ferroptosis analysis, KAT3B overexpression increased the Fe2 + (0.08 ± 0.01 vs 0.05 ± 0.01), MDA (29.24 ± 4.30 vs 22.06 ± 1.89), and LPO (5.07 ± 0.45 vs 2.88 ± 0.49) contents and decreased the GSH (7.86 ± 1.09 vs 11.06 ± 1.76) content in EA treated MCAO model rats. Collectively, our study demonstrates that EA plays a therapeutic role in CIRI through suppressing KAT3B-induced stabilization of ACSL4 to inhibit ferroptosis. These findings contribute to our understanding of the molecular mechanisms underlying the neuroprotective effects of EA and open new avenues for the development of innovative therapeutic strategies for CIRI.