Effects of TLR3 and TLR9 Signaling Pathway on Brain Protection in Rats Undergoing Sevoflurane Pretreatment during Cardiopulmonary Bypass.

Zhou Nan,Cao Huijuan,Zhang Tiezheng,Chen Keyan,Zhou Jin

doi:10.1155/2017/4286738

Zhou Nan, Cao Huijuan + Show 3 more

Open Access

https://doi.org/10.1155/2017/4286738

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Abstract

Objective To investigate the effects of TLR3 and TLR9 signaling pathway on brain injury during CPB in rats pretreated with sevoflurane and its possible molecular mechanism. Methods SD rats were randomly assigned to sham group, CPB group, and Sev group. Brain tissue was obtained at before CPB (T0), at CPB for 30 minutes (T1), 1 hour after CPB (T3), and 3 hours after CPB (T5). ELISA was used to measure S100-β and IL-6. Western blot was utilized to determine TLR3 and TLR9 expression. TUNEL was applied to detect neuronal apoptosis. Results Compared with CPB group, at T1, at termination after 1 hour of CPB (T2), T3, 2 hours after CPB (T4) and T5, S100-β and IL-6 decreased in Sev group. Compared with CPB group, IFN-β were increased in Sev group, except T0. Compared with CPB group, TLR3 expression increased, and TLR9 and NF-κB decreased in Sev group. The apoptotic neurons were less in Sev group than in CPB group (P < 0.05). Conclusion Sevoflurane intervention can activate TLR3 and TLR9 signaling pathway, upregulate TLR3 expression and downstream TRIF expression, decrease TLR9 expression, and downregulate downstream NF-κB expression in CPB rat models, thereby mitigating brain injury induced by inflammatory response during CPB.

Highlights

The emergence, application, and popularization of cardiopulmonary bypass (CPB) have led to the switch of cardiovascular surgery and significantly improve the survival rate of patients [1]
Compared with the CPB group, serum and brain IL-6 concentrations significantly diminished in the Sev group at T1–T5 (P < 0.05)
Compared with the CPB group, TLR3 expression significantly increased at T1, T3, and T5 in the sevoflurane pretreatment group (P < 0.05; Figure 4)

Summary

Introduction

The emergence, application, and popularization of cardiopulmonary bypass (CPB) have led to the switch of cardiovascular surgery and significantly improve the survival rate of patients [1]. The disadvantage associated with CPB is its damage to other systems in the body. Researchers have developed various measures to reduce CPB damage to the body and significantly improve patient survival and reduce the incidence of other systemic complications, but the incidence of complications of the nervous system is relatively constant; for example, the incidences of stroke and encephalopathy are approximately 2%–5% and 10%–30%, respectively [2].

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