禁食对蛋鸡肝脏腺苷-磷酸激活的蛋白激酶活性的影响

腺苷 -磷酸 (AMP)激活的蛋白激酶 (AMP- acti-vated protein kinase,AMPK)是丝氨酸激酶家族的一员 ,由 AMP和其上游激酶 AMPK激酶所活化 ,对细胞内 AMP/ATP的变化非常敏感 [1] ,被称为真核细胞的“代谢感受器”[2 ]。研究发现在跑步 [3 ,4 ]、电刺激肌肉 [5,6]或禁食应激后 [7] ,大鼠肝脏和肌肉中的AMPK活性升高数倍 ,乙酰辅酶 A羧化酶 (ACC)活性显著下降甚至丧失 ,丙二酸单酰辅酶 A产量降低甚至为零 ,脂肪酸合成受抑。同时 ,AMPK活化后 ,脂肪酸的氧化率显著提高 ,CO2 和酮体生成量明显增加[4 ,8] 。这些均表明 ,AMPK活化…     

二甲双胍通过AMPK/STAT3信号通路抑制星形胶质细胞的反应性

探讨二甲双胍对体外培养的大鼠脊髓星形胶质细胞反应性的作用及机制。方法 使用三因子（TNF-α、IL-1α、C1q）诱导产生反应性星形胶质细胞,RT-qPCR及Westernblot检测补体3（C3）的表达;使用5、10、20 mM浓度的二甲双胍处理,Westernblot检测星形胶质细胞中腺苷酸激活蛋白激酶（AMPK）与信号转导和转录激活因子3（STAT3）磷酸化水平;采用AMPK抑制剂Compound C处理,检测AMPK和STAT3磷酸化水平。结果 形态学及RT-qPCR结果显示：与对照组相比,三因子处理改变了星形胶质细胞形态并显著提高了C3的表达（P＜0.05）,表明成功建立反应性星形胶质细胞模型。RT-qPCR结果及Westernblot结果显示：与对照组相比,二甲双胍对C3表达有明显的抑制作用,呈现浓度依赖性（P＜0.05）。在诱导星形胶质细胞反应性过程中,与对照组相比,AMPK的磷酸化水平显著降低（P＜0.05）,使用不同浓度二甲双胍处理后,AMPK的磷酸化水平显著增加且呈浓度依赖性（P＜0.05）,同时信号传导及STAT3的磷酸化水平显著降低且呈浓度依赖性（P＜0.05）。AMPK抑制剂Compound C处理后显著抑制了二甲双胍导致的AMPK活性升高及STAT3活性降低,同时抑制了C3表达下调（P＜0.05）。结论 二甲双胍通过AMPK/STAT3信号通路抑制星形胶质细胞的反应性     

Vascular Effects of the Polyphenolic Nutraceutical Supplement Taurisolo®: Focus on the Protection of the Endothelial Function

Preservation of vascular endothelium integrity and functionality represents an unmet medical need. Indeed, endothelial dysfunction leads to decreased nitric oxide biosynthesis, which is prodromic of hypertension and hypercoagulability. In this panorama, the nutraceutical supplement Taurisolo^®, a polyphenolic extract from Aglianico cultivar grape, rich in catechin and procyanidins, was evaluated as a vasoprotective, vasorelaxing, anti-hypertensive and anti-coagulant agent in: cell lines, isolated vessels, in vivo models of chronic hypertension and hypercoagulability, and in clinical tests of endothelial reactivity. Taurisolo^® demonstrated to fully protect vascular cell viability from oxidative stimulus at 100 µg/mL and evoke vasorelaxing effects (Emax = 80.6% ± 1.9 and pEC50 = 1.19 ± 0.03) by activation of the Sirtuins-AMPK-pathway. Moreover, Taurisolo^®, chronically administered at 20 mg/Kg/die in in vivo experiments, inhibited the onset of cardiac hypertrophy (heart weight/rat weight = 3.96 ± 0.09 vs. 4.30 ± 0.03), hypercoagulability (decrease of fibrinogen vs. control: p < 0.01) and hypertension (mean of Psys: 200 ± 2 vs. control 234 ± 2 mmHg) and improved endothelial function (Emax = 88.9% ± 1.5 vs. control 59.6% ± 3.6; flow-mediated dilation in healthy volunteers after 400 mg twice daily for 8 weeks vs. baseline: p = 0.019). In conclusion, Taurisolo^® preserves the vascular function against ox-inflamm-ageing process and the consequent cardiovascular accidents.     

芒果苷对胰岛素抵抗HepG2细胞糖脂代谢的影响

目的:分析芒果苷(MGF)对胰岛素抵抗HepG2细胞(IR-HepG2细胞)糖脂代谢的影响,并探讨潜在机制.方法:以人肝癌HepG2细胞为对象,以1 mmol/L棕榈酸+2 mmol/L油酸联合培养建立IR-HepG2细胞模型.以盐酸二甲双胍为阳性对照,分别检测低、中、高浓度MGF(125、250、500μmol/L)...     

AMPK在保护血管功能中研究进展

腺苷酸活化蛋白激酶(AMPK)是一种丝氨酸/苏氨酸蛋白激酶,它是细胞内能量感受器并且参与了细胞和全身器官的能量代谢调节。AMPK的激活有许多潜在的抗动脉粥样硬化的效果,包括减少炎症细胞黏附在内皮上,减少脂质氧化引起的脂质累计和炎症细胞的增殖,刺激细胞抗氧化保护的基因表达和一氧化氮形成的酶。除了用于心血管和代谢性疾病的药物如他汀类,二甲双胍和噻唑烷二酮类之外,中医药宝库中也有许多涉及了AMPK的激活。总的来说,AMPK的激活与维护血管健康有密不可分的关系。综述了AMPK在保护血管功能中作用及机制的研究进展。     

丹参酮ⅡA在3T3-L1脂肪细胞中促进脂联素的组装(英文)

目的:研究丹参酮IIA对3T3-L1脂肪细胞中脂联素表达和蛋白多聚化的作用。方法:用油红染色鉴定3T3-L1脂肪细胞的分化状态。用Real-time PCR检测基因的mRNA表达水平。用2%15%梯度SDS-PAGE及Western blot检测脂联素三种聚体。用siRNA技术进行基因沉默。结果:本研究发现传统中药丹参中的萘醌二萜类成分丹参酮IIA在脂肪细胞中激活AMPK通路,同时抑制脂肪细胞分化,降低脂联素的表达。而在前体脂肪细胞分化过程或成熟脂肪细胞中加入丹参酮IIA进行处理,均明显促进脂联素的多聚化,增加高聚体的浓度。抑制AMPK通路能够解除丹参酮IIA对脂联素的作用。结论:丹参酮IIA通过激活AMPK在3T3-L1脂肪细胞中促进脂联素的组装。     

Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-α-stimulated monocytes to endothelial cells and suppressed the TNF-α induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-α-induced nuclear factor-κB activation, which was attenuated by pretreatment with N^G-nitro-l-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease.     

牛蒡子苷对L6骨骼肌细胞中腺苷酸活化蛋白激酶信号通路的影响

目的：探讨牛蒡子苷在L6骨骼肌细胞中对葡萄糖消耗和腺苷酸活化蛋白激酶（ AMP?activated protein kinase, AMPK）信号通路的调节作用。方法用含2％胎牛血清的1640培养基诱导L6骨骼肌细胞分化,直至细胞生长出肌管,分化完成后的L6骨骼肌细胞用含有不同浓度牛蒡子苷的培养基培养24 h后,采用葡萄糖氧化酶法检测细胞葡萄糖消耗,western blot法检测AMPK的亚单位AMPKα和磷酸化腺苷酸活化蛋白激酶（ p?AMP?activated protein kinase,p?AMPKα）的蛋白表达水平;以real?time PCR法检测过氧化物酶体增生物激活受体γ共激活因子1α（ peroxisome?proliferator?activated receptorγcoactiva?tor?1α,PGC?1α） mRNA表达水平。结果牛蒡子苷浓度为1000 g／L 时,可增加 L6骨骼肌细胞的葡萄糖消耗,差异显著（ P＜0．01）;与对照组相比,牛蒡子苷呈浓度依赖性的增强L6骨骼肌细胞中p?AMPKα蛋白表达水平;并以相同的趋势增强PGC?1α mRNA表达水平。结论牛蒡子苷增加L6骨骼肌细胞的葡萄糖消耗,并激活AMPK／PGC?1α信号通路,具有潜在的改善胰岛素抵抗的作用。     

补阳还五汤通过AMPK/mTOR/ULK1信号通路调控自噬减轻大鼠脑缺血/再灌注损伤

目的探讨补阳还五汤抗大鼠脑缺血/再灌注损伤的AMPK/mTOR/ULK1自噬信号通路机制。方法用改良线栓法建造大鼠左侧脑缺血模型,各组大鼠每24 h给药1次,共3次。再灌注72 h后观察大鼠神经损伤情况和脑梗死体积改变;尼氏染色法和TUNEL染色法观察神经细胞形态、数量以及凋亡情况;Western blot检测自噬蛋白和AMPK/mTOR/ULK1自噬信号通路相关蛋白表达情况。结果补阳还五汤改善大鼠神经功能缺陷,减少脑梗死体积和神经细胞凋亡,减轻脑组织病理损伤;抑制AMPK磷酸化活化,解除AMPK对下游mTOR和ULK1的抑制,促进二者磷酸化激活,抑制细胞自噬。AMPK激动剂Metformin提高细胞自噬水平,同时逆转了补阳还五汤抗大鼠脑缺血/再灌注损伤作用。结论补阳还五汤介导AMPK/mTOR/ULK1自噬信号通路对脑缺血/再灌注损伤大鼠发挥神经保护作用。