【摘要】 目的：探究替普瑞酮又称香叶基香叶基丙酮，GGA）对脂多糖（LPS）诱导的心功能障碍的治疗作用及机制。方法：（1）取8周龄C57BL/6雄性野生型小鼠和热休克蛋白70(HSP70)羧基末端相互作用蛋白（CHIP）基因敲除小鼠，随机分为对照组、LPS组、LPS+GGA组和GGA组，每组8只。用腹腔注射LPS(25 mg/kg)的方法建立模型，于LPS刺激后1 h给予小鼠腹腔注射GGA(100 mg/kg)。利用小动物超声系统评估小鼠心脏功能；采集各组小鼠血清，检测血清肌酸激酶同工酶（CK-MB）和乳酸脱氢酶（LDH）水平；HE染色观察病理学改变；ELISA检测心脏组织中炎症因子肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的水平；Western blot检测各组心脏组织HSP70、CHIP、核转运蛋白α2(KPNA2)、髓过氧化物酶（MPO）、血管细胞黏附分子（VCAM）和细胞间黏附分子（ICAM）的蛋白表达以及细胞核NF-κB的水平。（2）利用小鼠心肌细胞HL-1，建立LPS刺激的离体细胞炎症模型。ELISA检测细胞上清中TNF-α和IL-6的水平；Western blot检测心肌细胞中HSP70、CHIP和KPNA2蛋白表达；免疫荧光染色观察细胞核NF-κB的表达。结果：（1）GGA有效改善LPS刺激小鼠的心脏功能，显著提高射血分数和左室短轴缩短率（P<0.01），减少血清CK-MB和LDH含量（P<0.01），减轻心肌损伤。（2）GGA显著减少LPS引起的TNF-α和IL-6炎症因子的释放（P<0.01），以及NF-κB的入核，降低心肌组织中KPNA2、MPO、VCAM和ICAM蛋白表达，增加心肌组织和细胞HSP70的水平（P<0.01）。（3）在CHIP基因敲除的心肌细胞和小鼠中，GGA不能抑制LPS引起的炎症反应，失去了改善LPS刺激小鼠心脏功能的作用。结论：GGA能够减轻LPS引起的心功能障碍，其作用机制与升高HSP70的表达，促进CHIP的活化，减少NF-κB的入核，抑制炎症因子的释放有关。CHIP的敲除使GGA丧失了减轻LPS诱导的炎症反应和心肌损伤的作用。更多还原

【Abstract】 AIM:To explore the therapeutic effect of teprenone(geranylgeranylacetone,GGA) on lipopolysaccharide (LPS)-induced cardiac dysfunction and its mechanism.METHODS:(1) Eight-week-old male C57BL/6 wildtype mice and carboxyl terminus of heat shock protein 70 (HSP70)-interacting protein (CHIP) gene knockout mice were randomly divided into control group,LPS group,LPS+GGA group and GGA group,with 8 mice in each group.The model was established by intraperitoneal injection of LPS (25 mg/kg),and 1 h after LPS stimulation,mice were given intraperitoneal injection of GGA (100 mg/kg).The technique of high-resolution ultrasonography system was used to evaluate the cardiac function of mice.The serum of mice from each group were collected to detect the levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH).HE staining was performed to observe histological changes of cardiac tissues.ELISA was used to detect the levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in cardiac tissues.Western blot was used to detect the protein levels of HSP70,CHIP,karyopherin-α 2 (KPNA2),myeloperoxidase (MPO),vascular cell adhesion molecule (VCAM),intercellular cell adhesion molecule (ICAM),and nuclear factor-κB (NF-κB) in cardiac tissues.(2) In vitro cell inflammation model was established using mouse myocardial cells HL-1 stimulated with LPS.ELISA was used to detect the levels of TNF-α and IL-6 in cell supernatants.Western blot was used to detect the protein expression levels of HSP70,CHIP,and KPNA2 in myocardial cells.Immunofluorescence staining was performed to observe the content of nuclear NF-κB.RESULTS:(1) GGA effectively improved cardiac function of LPS-stimulated mice,significantly increased ejection fraction and left ventricular fractional shortening (P<0.01),reduced serum levels of CK-MB and LDH (P<0.01),and alleviated myocardial injury.(2) GGA significantly reduced the release of TNF-α and IL-6 caused by LPS (P<0.01),as well as nuclear translocation of NF-κB,decreased the levels of KPNA2,MPO,VCAM and ICAM in cardiac tissues,and increased the levels of HSP70 in cardiac tissues and cells (P<0.01).(3) In CHIP knockout myocardial cells and mice,GGA failed to inhibit LPS-induced inflammatory response and lost its effect on improving cardiac function.CONCLUSION:The protective effect of GGA against LPS-caused cardiac dysfunction of mice is related to increasing expression of HSP70 and promoting CHIP activation,which inhibits the translocation of NF-κB into nucleus and suppresses inflammatory factor release.CHIP knockout abolishes the effects of GGA on reducing LPS-induced inflammatory response and myocardial injury.更多还原