Anesthesia and surgery induce changes in endogenous brain protective protein (RNF146) and delirium-like behavior in aged rats.

Background: Postoperative delirium (POD) is a common complication after anesthesia and surgery, especially in the elderly. RNF146 has neuroprotective effects in cerebral ischemia, hypoxia, and chronic neurological diseases. However, whether RNF146 expression is related to the occurrence and development of POD remains unclear. Therefore, in this study, we aimed to determine whether RNF146 is involved in the occurrence of POD.

Methods: (Sprague-Dawley) male rats (18 months old) were splenectomized under sevoflurane anesthesia. The cognitive function of rats at 1, 3, and 7 d after anesthesia and surgery was evaluated. Changes in the expression of neuroinflammatory cytokines, IL-6 and IL-10, and RNF146 were measured in the hippocampus in both control group (con) and anesthesia (AS) group. We examined cognitive outcomes and expression of inflammatory factors and RNF146 in con and AS mice using cluster analysis.

Results: The cognitive ability and mobility of rats after anesthesia and surgery at day 1, 3, and 7 decreased, especially at day 3. Similarly, the expression of neuroinflammatory factors and RNF146 increased after anesthesia and surgery at day 1, 3, and 7, and the increase was highest at day 3. The clustering and correlation analysis of RNF146 expression in the hippocampi of elderly rats revealed a correlation between POD and neuroinflammation resulting from anesthesia and surgery.

Conclusion: Anesthesia and surgery can lead to POD and neuroinflammation. The expression of RNF146 correlates with delirium and neuroinflammation caused by anesthesia and surgery.