Objective To develop and evaluate a mouse model of nonalcoholic steatohepatitis (NASH) induced by a high-fat and high-fructose (HFHFr) diet.Methods Six-week-old C3H mice were randomly divided into groups for HFHFr diet experimental modeling,high fat-only (HF) diet controls,high fructose-only (HFr) diet controls,and standard chow (SC) diet controls.The standard HFHFr diet was modified so that it consisted of 76.5％ standard chow,12％ lard,1％ cholesterol,5％ egg yolk powder,5％ whole milk powder,and 0.5％ sodium cholate,along with 20％ fructose drinking water.At the end of experimental weeks 4,8,and 16,measurements were taken for the NASH-related parameters of body mass,serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST),lipid profile,and wet liver weight (upon sacrifice).In addition,histological changes in the liver were evaluated by hematoxylin-eosin (HE) and oil red O staining.The significance of differences between groups was assessed by statistical analysis,using the methods of t-test,Wilcoxon rank sum test,x2 test,F test or Fisher's test as appropriate.Results As compared to the mice in the SC group at the corresponding time points,the mice in the HFHFr and HF groups showed significantly higher body mass and wet liver weight,as well as more extensive and robust lipid disposition in hepatic tissues as evidenced by oil red O staining.However,HE staining indicated that the HFHFr and HF groups had different degrees of macrosteatosis accompanied with intralobular inflammatory foci,with the former showing more remarkable NASH-related histological changes.Analysis at the end of week 16 showed that about 80％ of the mice in the HFHFr group had developed NASH [nonalcoholic fatty liver disease (NAFLD) activity score (NAS):＞5].The levels of low-and high-density lipoprotein (LDL and HDL) cholesterol,as well as the levels of ALT and AST,were increased from the end of week 4 to the end of week 8 for the HFHFr and HF groups.At the end of week 16,the two groups differed in the extent of increase in total cholesterol and LDL and HDL cholesterol,with only the HFHFr group showing statistically significant changes.Specifically,at the end of week 16,the HFHFr group showed ALT levels of 108.5 ± 93.34 U/L (F=5.099,P =0.005 vs.HF group:44.30 ± 35.71 U/L,HFr group:46.70 ± 17.95 U/L,SC group:24.70 ± 6.57 U/L),AST levels of 316.30 ± 208.98 U/L (F=6.654,P=0.001 vs.HF:132.12 ± 75.43 U/L,HFr:143.30 ± 38.53 U/L,SC:122.60 ± 12.76 U/L),total cholesterol levels of 5.18 ± 0.58 mmol/L (F=72:470,P =0.000 vs.HF:3.94 ± 0.75 mmol/L,HFr:2.30 ± 0.50 mmol/L,SC:2.02 ± 0.24 mmol/L),HDL cholesterol levels of 3.05 ± 0.49 mmol/L (F =25.413,P =0.000 vs.HF:2.65 ± 0.54 mmol/L HFr:1.77 ± 0.47 mmol/L,SC:1.58 ± 0.16 mmol/L),LDL cholesterol levels of 1.11 ± 0.23 mmol/L (F =83.297,P =0.000 vs.HF:0.72 ± 0.17 mmol/L,HFr:0.27 ± 0.04 mmol/L,SC:0.20 ± 0.05 mmol/ L).Conelusion The present study suggests that a mouse model of NASH can be successfully induced by a 16-week modified HFHFr diet.%目的 采用高脂高果糖饮食建立符合人类饮食习惯的非酒精性脂肪性肝炎(NASH)小鼠模型.方法 6周龄C3H野生型小鼠120只按体质量随机分到高脂高果糖组、高脂组、高果糖组、对照组各30只予以相应喂养,4、8、16周末分批处死小鼠,检测体质量、肝湿重、肝功能、脂代谢等NASH相关指标,肝组织HE、油红O染色评价病理学改变.计量资料两组间均数比较用t检验和Wilcoxon秩和检验,多组间均数比较采用方差分析,计数资料采用x2检验和Fisher确切概率法.结果 与同时点对照组比较,高脂高果糖组和高脂组小鼠体质量、肝湿重增加,油红O染色面积、密度增加,HE染色显示随造模时间延长出现不同程度脂肪变伴炎症灶,高脂高果糖组更明显,造模结束时80％非酒精性脂肪性肝病评分≥5,伴窦周纤维化.血清检测示:4周末,高脂高果糖组和高脂组总胆固醇及高、低密度脂蛋白明显增高;8周末,高脂高果糖组和高脂组血清高、低密度脂蛋白增加明显;16周末,高脂高果糖组、高脂组、高果糖组、对照组ALT分别为(108.5±93.34)U/L、(44.30±35.71)U/L、(46.70±17.95)U/L、(24.70±6.57)U/L,F=5.099,P=0.005;AST分别为(316.30±208.98) U/L、(132.12±75.43) U/L、(143.30±38.53) U/L、(122.60±12.76) U/L,F=6.654,P=0.001;总胆固醇分别为(5.18±0.58) mmol/L、(3.94±0.75)mmol/L、(2.30±0.50) mmol/L、(2.02±0.24) mmol/L,F=72.470,P=0.000;高密度脂蛋白分别为(3.05±0.49) mmol/L、(2.65±0.54) mmol/L、(1.77±0.47) mmol/L、(1.58±0.16)mmol/L,F=25.413,P=0.000;低密度脂蛋白分别为(1.11±0.23) mmol/L、(0.72±0.17)mmol/L、(0.27±0.04) mmol/L、(0.20±0.05) mmol/L,F=83.297,P=0.000.高果糖组组织病理学、血清学改变均不明显.结论 高脂高果糖饮食喂饲4、8、16周可诱导小鼠出现可模拟NASH的疾病进程,出现典型的NASH肝组织学和肥胖等代谢表型.
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