目的：探讨α7烟碱型乙酰胆碱受体（α7nAChR）基因敲除对非酒精性脂肪性肝炎（ NASH）小鼠肝脏炎症的影响。方法2014年6月—2015年5月，选取40只 SPF 级雄性6周龄 C57BL/6J 小鼠和40只 SPF 级雄性6周龄α7nAChR基因敲除小鼠，采用随机数字表法分为 C57普通饲料组、C57高脂高糖组、基因敲除普通饲料组、基因敲除高脂高糖组，每组20只。C57普通饲料组、基因敲除普通饲料组小鼠给予普通饲料喂养，C57高脂高糖组、基因敲除高脂高糖组小鼠给予高脂饲料喂养同时饮用20%果糖饮用水，喂养24周，建立 NASH 小鼠模型；小鼠饲养期间定期称量体质量，并且尾静脉取血检测丙氨酸氨基转移酶（ ALT）、天冬氨酸氨基转移酶（ AST）、三酰甘油（TG）、总胆固醇（TC）水平。21周时 C57高脂高糖组、基因敲除高脂高糖组小鼠给予400μg/ kg 烟碱腹腔注射；C57普通饲料组、基因敲除普通饲料组小鼠给予等量0.9%氯化钠溶液腹腔注射，均1次/ d，共3周。24周后处死小鼠，眼球取血，酶联免疫吸附试验（ELISA）法检测血清炎性细胞因子白介素6（IL-6）、肿瘤坏死因子α（TNF-α）水平，观察小鼠肝脏外观变化及肝脏湿重，肝脏病理切片染色观察炎症程度和脂肪变性情况。结果第12、15、18、21、24周时，C57高脂高糖组、基因敲除高脂高糖组小鼠体质量较 C57普通饲料组、基因敲除普通饲料组升高（P <0.05）；第12、15、18、21、24周时，基因敲除高脂高糖组小鼠体质量较 C57高脂高糖组升高（P <0.05）。C57高脂高糖组、基因敲除高脂高糖组小鼠第8、16、24周时血清 ALT、AST、TG、TC 水平，第24周时血清 IL-6、TNF-α水平、肝脏湿重较 C57普通饲料组、基因敲除普通饲料组升高（P <0.05）；基因敲除高脂高糖组小鼠第8、16、24周时血清 ALT、AST 水平，第16、24周时血清 TG、TC 水平，第24周时血清 IL-6、TNF-α水平、肝脏湿重较 C57高脂高糖组升高（P <0.05）。病理切片苏木素-伊红（HE）、油红染色结果显示：C57普通饲料组、基因敲除普通饲料组小鼠炎症程度和脂肪变性均不明显，C57高脂高糖组、基因敲除高脂高糖组小鼠在第8 周开始出现轻微炎症和脂肪变性，以小脂滴为主，到第16、24周，炎症和脂肪变性逐渐加重，脂肪变性以中、大滴为主，基因敲除高脂高糖组小鼠肝脏组织炎症程度和脂肪变性均明显重于 C57高脂高糖组小鼠。结论α7nAChR基因敲除能够明显加重 NASH 小鼠的肝脏炎症。%Objective To investigate the effect of α7nAChR gene knockout on the liver inflammation of non - alcoholic steatohepatitis(NASH)mice. Methods From June 2014 to May 2015,40 SPF male 6 - week - old C57BL/ 6J mice and 40 SPF male 6 - week - old α7nAChR gene knockout mice were selected. The mice were divided into C57 mice normal diet group (group 1),C57 mice high fat and fructose diet group( group 2),gene knockout mice normal diet group( group 3),gene knockout mice high fat and fructose diet group(group 4),with 20 rats in each group. Group 1 and group 3 were fed up with either normal feed,group 2 and group 4 were fed up with high - fat feed plus 20% fructose drinking water,24 weeks to generate an NASH model. The body weight of the mice during the feeding period was measured on a regular basis,and blood was sampled from the caudal vein to detect the levels of ALT,AST,TG and TC. In week 21,group 2 and group 4 were given 400 μg/ kg nicotine by intraperitoneal inJection,and group 1 and group 3 were given the same volume of 0. 9% sodium chloride solution by intraperitoneal inJection for one time per day for 3 weeks. 24 weeks later,the mice were killed. Blood was sampled from eyeball to detect the levels of IL-6 and TNF-α by ELISA method,the changes of color and liver wet weight were recorded,and liver pathological section staining was conducted to observe inflammation degree and fatty degeneration. Results In week 12,15, 18,21 and 24,group 2 and group 4 were higher than group 1 and group 3 in body weight(P < 0. 05). In week 12,15,18, 21 and 24,group 4 was higher than group 2 in body weight(P < 0. 05). Group 2 and group 4 had higher ALT,AST,TG and TC levels in week 8,16 and 24 and higher IL-6 and TNF-α levels and higher liver wet weight in week 24 than group 1 and group 3(P < 0. 05);group 4 had higher ALT and AST levels in week 8,16 and 24,higher TG and TC levels in week 16 and 24, higher IL-6 and TNF-α levels and higher liver wet weight in week 24 than group 2(P < 0. 05). The pathological section of HE and oil red staining showed that group 1 and group 3 had no obvious inflammation degree and fatty degeneration,and group 2 and group 4 showed slight inflammation and fatty degeneration which was mainly manifested as small fat drops in week 8 and showed severer inflammation and fatty degeneration which featured medium or large small fat drops in week 16 and 24,and group 4 had severer inflammation degree and fatty degeneration than group 2. Conclusion α7nAChR gene knockout can significantly aggravate the liver inflammation in NASH mice.
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