Stellate ganglion block improves postoperative cognitive dysfunction in aged rats by SIRT1-mediated white matter lesion repair

Abstract

Abstract Background Postoperative cognitive dysfunction is a common complication of the central nervous system after surgery, especially in elderly patients. White matter lesions cause cognitive impairment. Although stellate ganglion block (SGB) is an effective intervention for postoperative cognitive dysfunction, the exact mechanism remains unclear. The SIRT1 signaling pathway is involved in the process that SGB alleviates postoperative cognitive dysfunction. However, the underlying mechanisms that SGB improves postoperative cognitive dysfunction through SIRT1 in aged rats and its association with white matter lesion repair are yet to be elucidated. Methods To simulate a surgery-induced cognitive dysfunction-like condition, 20-month-old aged male Sprague-Dawley rat was subjected to splenectomy to induce cognitive impairment. Cognitive function was assessed by Morris water maze test. Western blotting was used to determine SIRT1 and NF-κB expression levels in the hippocampus and white matter under different circumstances. Immunohistochemistry was used to examine SIRT1 expression in white matter. The morphology of neural cells in white matter was observed by HE staining. NF-κB activity was measured by EMSA. The serum and white matter TNF-α, IL-6 and IL-10 levels were determined by ELISA. Results After splenectomy, the expression of SIRT1 in the rat hippocampus and white matter was dramatically decreased, NF-κB activity was enhanced, the levels of TNF-α, IL-6 and IL-10 in serum and white matter were increased, and rat showed significant cognitive impairment. After treatment with stellate ganglion block, activation of SIRT1 mediated by the SIRT1/NF-κB signaling pathway alleviated neuroinflammation, reversed white matter injury, and ameliorated surgery-induced cognitive dysfunction. Conclusion In conclusion, we provide strong evidence to demonstrate that postoperative cognitive dysfunction in elderly patients is associated with white matter injury, and stellate ganglion block can improve postoperative cognitive impairment in the older by reversing white matter lesion by activating SIRT1.