Remimazolam Attenuates Neurological Injury After TBI: A Potential Role of α7nAChR-Associated Mitophagy Enhancement and Pyroptosis Suppression in BV2 Cells

Longfei Li, Rugan Bao, Yao Meng, Xiaoyan Li, Hangbing Li, Pengyu Duan, Yonghong Bi, Jiali Chen, Yuling Xing, Lan Luo, Yang Yu, Miao Yu, Muyan Cui, Bing ZhangDepartment of Anesthesiology, Second Affiliated Hospital of Harbin Medical University, Harbin, People’s Republic of ChinaCorrespondence: Bing Zhang, Department of Anesthesiology, Second Affiliated Hospital of Harbin Medical University, No. 246 Xuefu Road, Nangang District, Harbin, 150086, People’s Republic of China, Tel +86 451 86605028, Email [email protected]: Traumatic brain injury (TBI) remains a major cause of disability and mortality worldwide. This study investigated whether remimazolam improves neurological outcomes after experimental TBI and whether these effects are associated with α 7 nicotinic acetylcholine receptor (α 7nAChR) related regulation of mitophagy and pyroptosis.Material and Methods: Computational analyses, LPS/ATP-stimulated BV2 cells, and a mouse model of TBI were used. Molecular docking, molecular dynamics simulations, cellular thermal shift assays, and calcium influx assays were performed to evaluate the potential interaction between remimazolam and α 7nAChR. Mitochondrial function, mitophagy-related markers, NLRP3, ASC, caspase-1, and GSDMD-N were assessed in BV2 cells. Neurological and behavioral outcomes were evaluated using the modified neurological severity score, rotarod test, open-field test, and novel object recognition test, together with histopathological, inflammatory, and molecular analyses of peri-lesional brain tissue. Methyllycaconitine (MLA) and flumazenil were used to assess the involvement of α 7nAChR related signaling and the classical benzodiazepine sensitive GABA_A receptor pathway.Results: Remimazolam showed a predicted interaction with α 7nAChR. In vitro, it enhanced mitophagy, improved mitochondrial function, and reduced the expression of NLRP3, Caspase-1, ASC, and GSDMD-N. In vivo, remimazolam improved neurological and behavioral outcomes, attenuated histopathological brain injury and neuroinflammation, promoted mitophagy and suppressed pyroptosis. MLA and flumazenil partially attenuated these protective effects.Conclusion: Remimazolam attenuates neurological injury in experimental TBI and LPS/ATP-stimulated BV2 cells, partly through α 7nAChR associated mitophagy enhancement and pyroptosis inhibition, while GABA_A receptor signaling may also be involved in these effects. These findings support its potential neuroprotective value in anesthesia and perioperative management.Keywords: traumatic brain injury, remimazolam, α 7nAChR, microglia, mitophagy, pyroptosis