Zhou Zhou, Chen Xiaomei, Li Fuqiang, Tang Cuilan
Department of Anesthesiology, The Second Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou 310005, China.
Zhonghua Gan Zang Bing Za Zhi. 2015 Jan;23(1):64-8. doi: 10.3760/cma.j.issn.1007-3418.2015.01.015.
To investigate the effects and mechanisms of the inflammatory reaction related to nonalcoholic steatohepatitis (NASH) and induced by activation of the cholinergic anti-inflammatory pathway.
A mouse model of NASH was established by feeding a high-fat and high-sugar diet.Activation of the cholinergic anti-inflammatory pathway was achieved by nicotine administration to the NASH modeled mice and normal controls. Liver biopsies were taken and the concentrations of cytokines were measured. Isolated liver primary Kupffer cells and RAw264.7 cells were cultured, pre-treated or not with lipopolysaccharide (LPS) and exposed to nicotine, after which the supernatant concentrations of IL-6 and TNFa were determined by ELISA. The protein expression levels of phosphorylated (p)-NF-kB and I k B were detected in primary cultured Kupffer cells by western blotting.
The mouse model of NASH was successfully established, as evidenced by findings from liver biopsy and serum liver function tests. The degree of liver inflammation in the NASH mice decreased after nicotine administration, and the level of serum TNFa also significantly decreased. The levels of serum TNFa were 21.95+/-0.8 pg/mL in nicotine-treated mice and 38.07+/-1.7 pg/mL in the non-nicotine-treated NASH mice (P less than 0.05). The nicotine treatment also significantly reduced the concentration of TNFa in the culture supernatants of Kupffer cells after LPS stimulation; moreover, the supernatant level of TNFa decreased significantly after the nicotine treatment (Pless than 0.05). LPS stimulation of the RAw264.7 cells led to an increased level ofp-NF-kB and a reduced level ofI-kB, suggesting that the NF-kB pathway had been activated; different doses of nicotine pre-treatment led to down-regulation of the p-NF-kB level and up-regulation of the I-kB level, both in dose-dependent manners.
Activating the cholinergic anti-inflammatory pathway inhibits the NASH-related inflammatory reaction, and the mechanism for this inhibition involves the NF-kB signaling pathway.
探讨胆碱能抗炎通路激活诱导的与非酒精性脂肪性肝炎（NASH）相关的炎症反应的影响及机制。
通过高脂高糖饮食建立NASH小鼠模型。对NASH模型小鼠和正常对照小鼠给予尼古丁以激活胆碱能抗炎通路。取肝脏组织活检并检测细胞因子浓度。分离培养肝脏原代库普弗细胞和RAW264.7细胞，用脂多糖（LPS）预处理或不预处理，然后暴露于尼古丁，之后通过酶联免疫吸附测定法（ELISA）测定白细胞介素-6（IL-6）和肿瘤坏死因子α（TNFα）的上清液浓度。通过蛋白质免疫印迹法检测原代培养的库普弗细胞中磷酸化（p）-核因子κB（NF-κB）和IκB的蛋白表达水平。
肝脏活检和血清肝功能检查结果证明成功建立了NASH小鼠模型。给予尼古丁后，NASH小鼠的肝脏炎症程度降低，血清TNFα水平也显著降低。尼古丁处理组小鼠血清TNFα水平为21.95±0.8皮克/毫升，未用尼古丁处理的NASH小鼠血清TNFα水平为38.07±1.7皮克/毫升（P<0.０5）。尼古丁处理还显著降低了LPS刺激后库普弗细胞培养上清液中TNFα的浓度；此外，尼古丁处理后TNFα的上清液水平显著降低（P<0.０5）。LPS刺激RAW264.7细胞导致p-NF-κB水平升高和IκB水平降低，表明NF-κB通路被激活；不同剂量的尼古丁预处理均导致p-NF-κB水平下调和IκB水平上调，且均呈剂量依赖性。
激活胆碱能抗炎通路可抑制与NASH相关的炎症反应，这种抑制作用的机制涉及NF-κB信号通路。
