腺苷酸激活蛋白激酶磷酸化障碍导致烧伤后骨骼肌脂质沉积的实验研究  

AMPK phosphorylation disorder induces intramyocellular lipids deposition in mice after burn injury

作　　者：王超[1] 吴丹[1] 王宏宇[1] 胡建红[1] 张勇[1] 彭曦[1] 

机构地区：[1]第三军医大学西南医院全军烧伤研究所、创伤、烧伤与复合伤国家重点实验室,重庆400038

出　　处：《第三军医大学学报》2015年第9期845-850,共6页Journal of Third Military Medical University

基　　金：国家自然科学基金面上项目(81372049)~~

摘　　要：目的探讨影响腺苷酸激活蛋白激酶(AMP activated protein kinase,AMPK)/乙酰辅酶a羧化酶(acetyl Co A carboxylase,ACC)信号通路导致烧伤后骨骼肌脂质沉积(intramyocellular lipids,IMCLs)的分子机制。方法采用30%体表面积Ⅲ度烧伤小鼠模型,将54只BALB/c小鼠按随机数字表法分为正常对照组、AMPK激活剂(acadesine,AICAR)组、烧伤组、烧伤+AICAR组,同位素标记法检测各组小鼠腓肠肌中肉碱脂酰转移酶-1(carnitine palmitoyl transferase-1,CPT1)活性变化,Western blot检测各组小鼠腓肠肌中AMPK-α、p-AMPK-α、ACC及p-ACC表达水平,通过油红O染色和甘油三酯(triglyceride,TG)测定法评估各组小鼠腓肠肌IMCLs情况。结果烧伤后小鼠腓肠肌中ACC表达量较伤前显著升高(P<0.05),而AMPK-α、p-AMPK-α、p-ACC以及CPT1活性均显著降低(P<0.05)。在AICAR作用下,正常小鼠腓肠肌中p-AMPK-α表达显著升高[(1.16±0.08)vs(2.38±0.22),P<0.05],p-ACC表达显著升高[(1.74±0.10)vs(3.72±0.18),P<0.05],CPT1活性显著升高[(2.95±0.39)nmol/(min·mg)vs(6.35±0.68)nmol/(min·mg),P<0.05],TG含量显著降低[(3.88±0.40)mmol/g vs(2.89±0.54)mmol/g,P<0.05]。烧伤+AICAR组小鼠腓肠肌中p-AMPK-α、p-ACC、CPT1活性及甘油三酯含量较烧伤组无显著差异(P>0.05)。正常对照组和AICAR组正常小鼠腓肠肌组织切片油红O染色未见明显脂质沉积,而烧伤组和烧伤+AICAR组烧伤小鼠腓肠肌组织切片油红O染色均显示有大量脂质沉积,两组间并无显著差异(P>0.05)。结论骨骼肌中AMPK磷酸化障碍是烧伤后IMCLs的重要分子机制之一。Objective To determine the effect of AMP activated protein kinase （AMPK）/acetyl CoA carboxylase （ACC） signal pathway on the deposition of intramyocellular lipids （IMCLs） and investigate its underlying mechanisms. Methods Fifty-four BALB/c mice were inflicted with 30% total body surface area full-thickness burns, and then randomly divided into 4 groups, that is, control, acadesine treatment （AICAR, AMPK activator）, burn control, and burn-AICAR treatment groups. First, mitochondria were isolated to test the activity of carnitine palmitoyl transferase-1 （ CPT1 ） in gastrocnemius by isotope labeling. Second, Western blotting was used to detect the expression of ACC, AMPK-ct and theirs phosphorylation in the gastrocnemius. Then IMCLs were evaluated by oil red O dye and triglyceride （TG） contents measurement. Results Burn injury resulted in a markedly increase in ACC content （P 〈 0.05 ）, and significant decrease in CPTI activity and expression of AMPK-a, p-AMPK-a and p-ACC in the gastrocnemius （P 〈 0.05）. After AICAR treatment, the expression of p-AMPK-alpha （ 1.16 ± 0.08 vs 2.38 ± 0.22, P 〈 0.05 ） and p-ACC （1.74 ± 0.10 vs 3.72 ±0.18, P 〈0.05 ） were significantly increased in the gastrocnemius than in sham burn group, the activity of CPTI was significantly increased [2.95±0.39 vs 6.35±0.68 nmol/（ min · mg）, P 〈 0.05 ], and the content of TG was markedly decreased （3.88 ± 0.40 vs 2.89 ± 0.54 mmol/g, P 〈 0.05）. In contrast, the 2 burned groups did not show any marked difference with A1CAR treatment （ P 〉 0.05 ）. Besides, burn injury induced more lipid deposition in the gastrocnemius. This deposition of IMCLs was not be attenuated by AICAR （ P 〉 0. 05 ）. Conclusion AMPK phosphorylation disorder is one of important molecular mechanism for burn-induced IMCLs deposition.

关 键 词：烧伤 骨骼肌脂质沉积 腺苷酸激活蛋白激酶 乙酰辅酶A羧化酶 肉碱脂酰转移酶-1 

分 类 号：R322.74[医药卫生—人体解剖和组织胚胎学] R364.2[医药卫生—基础医学]