AMP活化蛋白激酶研究进展

能量代谢失衡是肥胖、糖尿病及代谢综合征的主要原因.AMP活化蛋白激酶(AMPK)是一种重要的蛋白激酶,可以调节能量代谢,开启分解代谢途径,如脂肪酸氧化和糖酵解,从而增加ATP的产生,同时关闭合成代谢途径,如多种脂类、蛋白质及糖原的合成,减少ATP的消耗.在增加骨骼肌对匍萄糖的摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.AMPK不仅町以在细胞水平作为"能量调节器",在整体水平还可以通过激素和细胞因子,如瘦素、脂联素和ghrelin调节机体的能量代谢.凼而,阐明AMPK在不同组织细胞及整体水平上调节糖脂代谢的机制是今后该领域的研究热点,也是临床治疗肥胖、2型糖尿病及代谢综合征等疾病的有效靶点.     

腺苷酸活化蛋白激酶与胰岛素抵抗

腺苷酸活化蛋白激酶（AMP-activated protein kinase, AMPK）是一类重要的蛋白激酶,通过改变细胞代谢和调节基因转录恢复细胞ATP水平。AMPK参与了肌肉收缩介导的葡萄糖转运和脂肪酸氧化,抑制肝脏葡萄糖、胆固醇和甘油三酯产生,并具有调节食物摄取和体重的作用。AMPK信号通路是目前具有吸引力的治疗肥胖、胰岛素抵抗、2型糖尿病和其它代谢病的药理靶点。     

抵抗素与肝脏胰岛素抵抗的关系

抵抗素是一种脂肪细胞因子,研究发现高抵抗素水平可诱导肝脏胰岛素抵抗发生,其机制可能是抑制腺苷酸活化蛋白激酶(AMPK)磷酸化,上调糖异生关键酶PEPCK和G6Pase的表达促进糖异生,从而使肝糖输出增多。肝脏是胰岛素作用的重要靶点,也是机体代谢的关键器官。肝脏胰岛素抵抗时,糖脂代谢紊乱加重机体胰岛素抵抗,促进2型糖尿病的发生。AMPK是物质代谢的关键激酶,通过磷酸化作用调节糖脂代谢相关酶的活性以及调节机体的能量平衡。抵抗素通过AMPK调节肝糖代谢这一观点为探讨抵抗素在胰岛素抵抗中的作用提供了新的思路。     

二甲双胍抑制分化型甲状腺癌的作用及机制

二甲双胍是治疗糖尿病的一线药物,晚近其抗肿瘤效应受到广泛关注.研究发现,服用二甲双胍的2型糖尿病患者分化型甲状腺癌(differentiated thyroid cancer,DTC)的风险降低,其机制可能与一方面通过改善胰岛素抵抗、下调促甲状腺激素(thyroid-stimulating hormone,TSH)和激...     

Activation of AMPK/MnSOD signaling mediates anti-apoptotic effect of hepatitis B virus in hepatoma cells

AIM: To investigate the anti-apoptotic capability of the hepatitis B virus(HBV) in the HepG2 hepatoma cell line and the underlying mechanisms.METHODS: Cell viability and apoptosis were measured by MTT assay and flow cytometry, respectively. Targeted knockdown of manganese superoxide dismutase(Mn SOD), AMP-activated protein kinase(AMPK) and hepatitis B virus X protein(HBx) genes as well as AMPK agonist AICAR and antagonist compound C were employed to determine the correlations of expression of these genes.RESULTS: HBV markedly protected the hepatoma cells from growth suppression and cell death in the condition of serum deprivation. A decrease of superoxide anion production accompanied with an increase of Mn SOD expression and activity was found in Hep G2.215 cells. Moreover, AMPK activation contributed to the up-regulation of Mn SOD. HBx protein was identified to induce the expression of AMPK and Mn SOD. CONCLUSION: Our results suggest that HBV suppresses mitochondrial superoxide level and exerts an antiapoptotic effect by activating AMPK/Mn SOD signaling pathway, which may provide a novel pharmacological strategy to prevent HCC.     

AMPK regulation of fatty acid metabolism and mitochondrial biogenesis: Implications for obesity

Skeletal muscle plays an important role in regulating whole-body energy expenditure given it is a major site for glucose and lipid oxidation. Obesity and type 2 diabetes are causally linked through their association with skeletal muscle insulin resistance, while conversely exercise is known to improve whole body glucose homeostasis simultaneously with muscle insulin sensitivity. Exercise activates skeletal muscle AMP-activated protein kinase (AMPK). AMPK plays a role in regulating exercise capacity, skeletal muscle mitochondrial content and contraction-stimulated glucose uptake. Skeletal muscle AMPK is also thought to be important for regulating fatty acid metabolism; however, direct genetic evidence in this area is currently lacking. This review will discuss the current paradigms regarding the influence of AMPK in regulating skeletal muscle fatty acid metabolism and mitochondrial biogenesis at rest and during exercise, and highlight the potential implications in the development of insulin resistance.     

AMPK与胰岛素抵抗

腺苷酸活化蛋白激酶(AMPK)是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡。AMPK被激活后在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用。由于在调节糖和脂肪酸代谢方面的作用,AMPK可能为治疗肥胖、胰岛素抵抗和2型糖尿病提供了新的药理靶点。     

小檗碱的降糖作用独立于AMPK的信号通路

目的：研究小檗碱的降糖作用是否依赖于单磷酸腺苷激活蛋白激酶（AMPK）信号途径。方法培养HepG2细胞和C2C12细胞,给予不同浓度小檗碱处理。葡萄糖消耗实验和乳酸生成实验用于检测小檗碱的降糖以及刺激糖酵解的作用。AMPK抑制剂化合物C（Compound C,CC）和显性失活突变型AMPK,即腺病毒负显性AMPK（Ad-DN-AMPK）腺病毒用于抑制AMPK的表达和活性。Western印迹法用于检测AMPK以及乙酰辅酶A羧化酶（ACC）磷酸化水平,以评估AMPK通路的活性。结果小檗碱显著刺激了HepG2细胞和C2C12细胞的葡萄糖消耗和乳酸生成,并表现出剂量依赖性的药物作用。5和10μmol/L的小檗碱显著增加AMPK及其下游蛋白ACC的磷酸化水平。CC和Ad-DN-AMPK腺病毒转染能明显抑制细胞内AMPK信号通路的活性。然而,在AMPK活性被抑制的条件下,小檗碱依然能够显著增加细胞的葡萄糖消耗和乳酸生成。结论小檗碱通过刺激糖酵解而上调细胞的糖代谢,该作用无需AMPK信号通路的参与。即使在AMPK的表达或者活性被抑制的情况下,小檗碱依然能够发挥显著的降糖作用。     

AMPK - Activated Protein Kinase and its Role in Energy Metabolism of the Heart

Adenosine monophosphate - activated kinase (AMPK) plays a key role in the coordination of the heart's anabolic and catabolic pathways. It induces a cellular cascade at the center of maintaining energy homeostasis in the cardiomyocytes.. The activated AMPK is a heterotrimeric protein, separated into a catalytic α - subunit (63kDa), a regulating β - subunit (38kDa) and a γ - subunit (38kDa), which is allosterically adjusted by adenosine triphosphate (ATP) and adenosine monophosphate (AMP). The actual binding of AMP to the γ - subunit is the step which activates AMPK. AMPK serves also as a protein kinase in several metabolic pathways of the heart, including cellular energy sensoring or cardiovascular protection. The AMPK cascade represents a sensitive system, activated by cellular stresses that deplete ATP and acts as an indicator of intracellular ATP/AMP. In the context of cellular stressors (i.e. hypoxia, pressure overload, hypertrophy or ATP deficiency) the increasing levels of AMP promote allosteric activation and phosphorylation of AMPK. As the concentration of AMP begins to increase, ATP competitively inhibits further phosphorylation of AMPK. The increase of AMP may also be induced either from an iatrogenic emboli, percutaneous coronary intervention, or from atherosclerotic plaque rupture leading to an ischemia in the microcirculation. To modulate energy metabolism by phosphorylation and dephosphorylation is vital in terms of ATP usage, maintaining transmembrane transporters and preserving membrane potential. In this article, we review AMPK and its role as an important regulatory enzyme during periods of myocardial stress, regulating energy metabolism, protein synthesis and cardiovascular protection.     

AMPK-能量代谢感受器与可激活AMPK相关的药物研究进展

单磷酸腺苷活化蛋白激酶（AMPK）可以感受细胞能量代谢变化,调节细胞的葡萄糖、脂肪酸的代谢过程。AMPK与细胞生长、生存和多种代谢信号途径关系密切,研究发现AMPK信号途径涉及炎症、肿瘤和代谢疾病。本文综述AMPK的功能与炎症、肿瘤、代谢类疾病的关系和诸如水杨酸、二甲双胍等药物激活AMPK的研究进展。     

Oxidative stress: A cause and therapeutic target of diabetic complications

Oxidative stress is defined as excessive production of reactive oxygen species (ROS) in the presence of diminished anti‐oxidant substances. Increased oxidative stress could be one of the common pathogenic factors of diabetic complications. However, the mechanisms by which hyperglycemia increases oxidative stress are not fully understood. In this review, we focus on the impact of mitochondrial derived ROS (mtROS) on diabetic complications and suggest potential therapeutic approaches to suppress mtROS. It has been shown that hyperglycemia increases ROS production from mitochondrial electron transport chain and normalizing mitochondrial ROS ameliorates major pathways of hyperglycemic damage, such as activation of polyol pathway, activation of PKC and accumulation of advanced glycation end‐products (AGE). Additionally, in subjects with type 2 diabetes, we found a positive correlation between HbA1c and urinary excretion of 8‐hydroxydeoxyguanosine (8‐OHdG), which reflects mitochondrial oxidative damage, and further reported that 8‐OHdG was elevated in subjects with diabetic micro‐ and macro‐ vascular complications. We recently created vascular endothelial cell‐specific manganese superoxide dismutase (MnSOD) transgenic mice, and clarified that overexpression of MnSOD in endothelium could prevent diabetic retinopathy in vivo. Furthermore, we found that metformin and pioglitazone, both of which have the ability to reduce diabetic vascular complications, could ameliorate hyperglycemia‐induced mtROS production by the induction of PPARγ coactivator‐1α (PGC‐1α) and MnSOD and/or activation of adenosine monophosphate (AMP)‐activated protein kinase (AMPK). We also found that metformin and pioglitazone promote mitochondrial biogenesis through the same AMPK–PGC‐1α pathway. Taking these results, mtROS could be the key initiator of and a therapeutic target for diabetic vascular complications. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00013.x, 2010)     

AMP活化蛋白激酶的抗氧化作用

AMP活化蛋白激酶(AMPK)广泛参与细胞代谢,在调节细胞能量代谢过程中起重要作用.另外,AMPK还可以调节机体抗氧化能力,通过调节机体抗氧化防御系统蛋白的表达,如硫氧化还原蛋白(TRX)、NAD(P)H氧化酶、二氧化锰超氧化物歧化酶(MnSOD)、过氧化物酶体增殖物活化受体协同刺激因子(PGC)-1α等,减少机体活性...     

高糖条件下腺苷酸活化蛋白激酶对大鼠胃平滑肌细胞能量代谢调控机制的研究

目的探讨高糖条件下腺苷酸活化蛋白激酶(AMPK)对大鼠胃平滑肌细胞能量代谢调控机制的影响。方法制备并确定糖尿病胃轻瘫(DGP)大鼠模型,实验分为正常对照(NC)组和DGP组,抗体芯片观察AMPK磷酸化通路的变化,确定能量代谢相关功能蛋白;SeahorseXFe细胞能量代谢分析系统观察2-脱氧-D-葡萄糖(2-DG)与化合物C(Compound C)对高糖条件下大鼠胃平滑肌细胞耗氧率(OCR)与细胞外酸化率(ECAR)的影响;沉默AMPK后,观察高糖条件下大鼠胃平滑肌细胞能量代谢相关功能蛋白变化。结果高糖条件下AMPK抑制大鼠胃平滑肌细胞OCR的基础呼吸、最大呼吸值、三磷酸腺苷产量(P<0.05),促进大鼠胃平滑肌细胞ECAR的糖酵解水平和能力(P<0.01)。抗体蛋白芯片发现18个磷酸化差异抗体,涉及与能量代谢相关蛋白包括:p53、Ca²⁺/CaM依赖性蛋白激酶Ⅱ(CaMKⅡ)、Ca²⁺/CaM依赖性蛋白激酶Ⅳ(CaMKⅣ)、磷脂酰肌醇特异性磷酯酶C-β3(PLC-β3)、蛋白激酶A(PKA)、乙酰CoA羧化酶1(ACC1)、真核延伸因子2(eEF2)、真核延伸因子激酶2(eEF2K)。与HG(24 h)组比较,HG(48 h)组p53、ACC1、eEF2表达升高(P<0.05或P<0.01),PLC-β3表达降低(P<0.01)。与HG(48 h)组比较,HG(48 h)+siRNA组p53、ACC1表达降低(P<0.01)。与HG(24 h)组比较,HG(48 h)组p-CaMKⅡThr³⁰⁵/CaMKⅡ与p-CaMKⅣThr^196/200/CaMKⅣ比值升高(P<0.01)。与HG(48 h)组比较,HG(48 h)+siRNA组p-CaMKⅡThr³⁰⁵/CaMKⅡ比值降低(P<0.01)。HG(48 h)组PKA活性高于HG(24 h)组(P<0.01)。结论高糖条件下AMPK通过调控p53、ACC1、eEF2、CaMKⅡ、CaMKⅣ、PLC-β3及PKA生物学作用,抑制大鼠胃平滑肌细胞线粒体代谢途径及促进糖酵解途径。     

Exercise-induced AMPK activity in skeletal muscle: Role in glucose uptake and insulin sensitivity

The energy/fuel sensor 5′-AMP-activated protein kinase (AMPK) is viewed as a master regulator of cellular energy balance due to its many roles in glucose, lipid, and protein metabolism. In this review we focus on the regulation of AMPK activity in skeletal muscle and its involvement in glucose metabolism, including glucose transport and glycogen synthesis. In addition, we discuss the plausible interplay between AMPK and insulin signaling regulating these processes.     

AMP活化蛋白激酶研究进展

能量代谢失衡是肥胖、糖尿病及代谢综合征的主要原因.AMP活化蛋白激酶(AMPK)是一种重要的蛋白激酶,可以调节能量代谢,开启分解代谢途径,如脂肪酸氧化和糖酵解,从而增加ATP的产生,同时关闭合成代谢途径,如多种脂类、蛋白质及糖原的合成,减少ATP的消耗.在增加骨骼肌对匍萄糖的摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.AMPK不仅町以在细胞水平作为"能量调节器",在整体水平还可以通过激素和细胞因子,如瘦素、脂联素和ghrelin调节机体的能量代谢.凼而,阐明AMPK在不同组织细胞及整体水平上调节糖脂代谢的机制是今后该领域的研究热点,也是临床治疗肥胖、2型糖尿病及代谢综合征等疾病的有效靶点.     

The 60-kDa heat shock protein regulates energy rearrangement and protein synthesis to promote proliferation of multiple myeloma cells

To investigate the cellular mechanisms of multiple myeloma (MM), we used liquid chromatography-tandem mass spectrometry for proteomics analysis of CD138⁺ plasma cells from patients with MM and healthy controls. We found that the 60-kDa heat shock protein (HSP60, also known as HSPD1) was significantly upregulated in myeloma cells. HSP60 is an important chaperone protein that regulates the homeostasis of mitochondrial proteins and maintains mitochondrial function. Knockdown (KD) of HSP60 in myeloma cells resulted in inhibition of proliferation and reduced the quality of the mitochondria. Mitochondrial stress tests showed that HSP60 KD inhibited glycolysis and mitochondrial activity. Metabolomics showed a decrease in glycolysis and tricarboxylic acid cycle metabolites, and inhibited the formation of creatine and phosphocreatine by the reaction of S-adenosylmethionine (SAM) with amino acids mediated by demethyladenosine transferase 1, mitochondrial (TFB1M) and reduced energy storage substances. Moreover, HSP60 silencing influenced the synthesis of ribonucleotides and nicotinamide adenine dinucleotide phosphate (NADPH) by the pentose phosphate pathway to inhibit cell proliferation. HSP60 KD inhibited 5' adenosine monophosphate-activated protein kinase (AMPK), which inhibited the key enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), effecting the metabolism of fatty acids by inhibiting malonyl-coenzyme A. Our data suggest that reduced HSP60 expression alters metabolic reprogramming in MM, inhibits tumour progression and reduces mitochondrial-dependent biosynthesis, suggesting that HSP60 is a potential therapeutic target for MM treatment.     

AMP活化蛋白激酶研究进展

能量代谢失衡是肥胖、糖尿病及代谢综合征的主要原因.AMP活化蛋白激酶(AMPK)是一种重要的蛋白激酶,可以调节能量代谢,开启分解代谢途径,如脂肪酸氧化和糖酵解,从而增加ATP的产生,同时关闭合成代谢途径,如多种脂类、蛋白质及糖原的合成,减少ATP的消耗.在增加骨骼肌对匍萄糖的摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.AMPK不仅町以在细胞水平作为"能量调节器",在整体水平还可以通过激素和细胞因子,如瘦素、脂联素和ghrelin调节机体的能量代谢.凼而,阐明AMPK在不同组织细胞及整体水平上调节糖脂代谢的机制是今后该领域的研究热点,也是临床治疗肥胖、2型糖尿病及代谢综合征等疾病的有效靶点.