【摘要】 目的探讨中枢nesfatin-1表达下调对SD大鼠肝胰岛素信号通路的影响。方法将雄性SD大鼠随机分为普食喂养+人工脑脊液(a CSF)输注组(NCA组,n=10),普食喂养+Ad-sh GFP输注组(NCG组,n=10),普食喂养+Ad-sh NUCB2输注组(NCN组,n=10),高脂喂养+人工脑脊液(a CSF)输注组(HFA组,n=10),高脂喂养+Ad-sh GFP输注组(HFG组,n=10),高脂喂养+Ad-sh NUCB2输注组(HFN组,n=10)。构建第三脑室微量输注系统进行第三脑室干预,留取普食组大鼠下丘脑、肝脏、脂肪和肌肉组织采用Western印迹测定nesfatin-1表达。采用Western印迹法测定各组大鼠G6Pase及PEPCK的表达水平以和IR、IRS-1、AKT、STAT3及m TOR的蛋白磷酸化水平变化。结果和NCA或NCG组分别相比,NCN组下丘脑nesfatin-1表达显著降低(P<0.05),而外周组织(肝、脂肪及肌肉)nesfatin-1表达无显著差异。和NCA组相比,HFA组的G6Pase、PEPCK表达水平均显著增高,而IR、IRS-1、AKT、STAT3、m TOR的蛋白磷酸化水平均显著降低(P<0.05)。和NCA或NCG组相比,NCN组的G6Pase、PEPCK表达水平均显著增高,而IR、IRS-1、AKT、STAT3、m TOR的蛋白磷酸化水平均显著降低(P<0.05)。和HFA或HFG组相比,HFN组的G6Pase、PEPCK表达水平均显著增高,而IR、IRS-1、AKT、STAT3、m TOR的蛋白磷酸化水平均显著降低(P<0.05)。结论中枢Ad-sh NUCB2输注可下调SD大鼠下丘脑nesfatin-1表达,同时下调机体肝胰岛素信号通路级联反应蛋白水平,可能通过抑制m TOR/STAT3信号通路从而降低机体肝脏糖异生。更多还原

【Abstract】 Objective To investigate the effects of central nesfatin-1 knockdown on hepatic insulin signaling pathway. Methods Male Sprague-Dawley( SD) rats were randomly divided into normal-chow die( NCD) + a CSF( NCA,n = 10),NCD + Ad-sh GFP( NCG,n =10),NCD + Ad-sh NUCB2( NCN,n = 10),high-fat diet( HFD) + a CSF( HFA,n = 10),HFD + Ad-sh GFP( HFG,n = 10),HFD + Adsh NUCB2 groups( HFN,n = 10). After central intervention,NCD-fed rats were sacrificed and the expressions of nesfatin-1 in hypothalamic and peripheral tissues were examined. Other rats were sacrificed and the tissues were quickly taken away. The phosphorylated protein levels of IR,IRS-1,AKT,STAT3 and m TOR,and the protein levels of G6 Pase,PEPCK were evaluated by Western blot. Results After central Ad-sh NUCB2 intervention,hypothalamic nesfatin-1 protein levels was significantly decreased by 66% compared with rats that were given ACF or Ad-sh GFP( P<0. 05). However,no significant differences were found in nesfatin-1 expression in liver,muscle and adipose tissues.Compared with those of NCA group,the protein levels of G6 Pase and PEPCK in HFA group were increased significantly( P<0. 05). However,the phosphorylated protein levels of IR,IRS-1,AKT,STAT3 and m TOR in HFA group were decreased obviously( P<0. 05). Compared with those of NCA or NCG groups,the protein levels of G6 Pase and PEPCK in NCN group were increased significantly( P<0. 05). However,the phosphorylated protein levels of IR,IRS-1,AKT,STAT3 and m TOR in NCN group were markedly decreased( P < 0. 05). Compared with HFA or HFG groups,the levels of G6 Pase and PEPCK in HFN group were increased significantly( P<0. 05). However,the phosphorylated protein levels of IR,IRS-1,AKT,STAT3 and m TOR in HFN group were decreased significantly( P<0. 05). Conclusions Central Ad-sh NUCB2 intervention could decrease hypothalamic nesfatin-1 protein levels significantly. Knockdown of central nesfatin-1 could decrease the phosphorylation of several proteins in insulin signaling cascade. Moreover,central nesfatin-1 knockdown could lighten insulin sensitivity through inhibition of m TOR-STAT3 signaling pathway.更多还原