Lingo1 in the hippocampus contributes to cognitive dysfunction after anesthesia and surgery in aged mice.

Cognitive impairment caused by anesthesia and surgery is one of the most common complications with multiple etiologies that occurs in elderly patients. The underlying mechanisms are not fully understood, and there is a lack of therapeutic strategies. Increasing evidence has demonstrated that myelin loss, abnormal phosphorylation of the tau protein and neuronal apoptosis are substantial driving factors of cognitive deficits. However, the key regulatory factors involved in the pathology of postoperative cognitive dysfunction require further investigation. Herein, we identified a key regulator, Lingo1, whose expression significantly increased in hippocampal neurons after aged mice underwent unilateral nephrectomy. Elevated Lingo1 expression markedly activated the RhoA/ROCK1 signaling pathway through interactions with NgR and p75NTR, subsequently promoting myelin loss and abnormal phosphorylation of the tau protein. Moreover, the upregulation of Lingo1 in hippocampal neurons further inhibited the EGFR/PI3K/Akt pathway, which may increase neuronal apoptosis. These pathological changes ultimately lead to cognitive impairment in aged mice after surgery. Notably, Lingo1 knockdown significantly reversed pathological changes in the hippocampus and attenuated cognitive decline. In conclusion, our findings highlight that Lingo1 upregulation in hippocampal neurons promotes the occurrence and development of postoperative cognitive dysfunction by regulating myelin loss, abnormal tau phosphorylation and neuronal apoptosis, suggesting that Lingo1 might be a potential target for treating postoperative cognitive dysfunction.