Effects of lidocaine on neutrophil apoptosis induced by tumor necrosis factor alpha / 中国组织工程研究

ABSTRACT

BACKGROUND: Lidocaine is deemed to can attenuate the inflammatory response, but the mechanisms are poorly understood. Nuclear factor-κB (NF-κB) is a key process of imflammatory response. OBJECTIVE: To determine the effect of lidocaine on activation and apoptosis of NF-κB in human neutrophiis in vitro. DESIGN, TIME AND SETTING: The controlled experiment was conducted at the Jiangsu Provincial Key Laboratory of Anesthesiology from October 2006 to February 2007. MATERIALS: Tumor necrosis factor (TNF)-α (0127:B8) was purchased from Sigma, USA. Peripheral blood samples were obtained from healthy donors after their informed consent. METHODS: Human neutrephilic granulocytes were assigned into five groups: ① saline control, ② TNF-α, ③ TNF-α+ lidocaine 1.0 mmol/L, ④ TNF-α+ lidocaine 2.0 mmol/L, and ⑤ TNF-α+ lidocaine 4.0 mmol/L groups. Incubation wasperformed for 3 hours.MAIN OUTCOME MEASURES: The effects of lidocaine on expression of NF- κB mRNA and I- κB mRNA in the cytosol extracts were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), and content of p65 protein were analyzed by Western blot. Neutrophilic granulocyte apoptosis was detected on flow cytomatry after incubation 12 hours and 24 hours.RESULTS: The expression of NF- κB mRNA in the nuclear extracts was significantly decreased and I- κB mRNA in the cytosoI extracts was markedly increased in the lidocaine group. The expression of NF- κB was significantly better in the 2.0 mmol/L and 4.0 mmol/L lidocaine groups than in the 1.0 mmol/L lidocaine group (P< 0.05). No significant difference was detected between the 2.0 mmol/L lidocaine group and the 4.0 mmol/L lidocaine group (P0.05). Lidocaine could significantly inhibit peripheral blood neutrophilic granulocyte apoptosis induced by TNF-α (p < 0.05). The inhibitory effect was significantly better in the 4.0 mmol/L lidocaine group than in the 1.0 mmol/L lidocaine group (P < 0.05). CONCLUSION: Lidocaine (1.0, 2.0 and 4.0 mmol/L) can down-regulate the expressions of NF- κB subunit p65 mRNA and the content of p65 protein in human polymorphoneclear neutrophils, and can significant reverse the reduction of apoptosis induced by TNF-α.