心房颤动患者心房组织AMPK/PGC-1a通路表达改变的研究

目的 探讨心房颤动（房颤）患者心房肌组织中AMPK/PGC-1α信号通路表达是否改变,探究该通路在在房颤过程中的作用。方法 选择2018年12月至2019年11月在我科行心脏手术的患者76例,根据术前24 h动态心电图及病史分为房颤组（AF,41例）和窦性组（SR,35例）,术中切除左心耳组织留存。使用蛋白质印迹法（western blot,WB）检测心耳组织中AMPK、PGC-1α、NRF1、TFAM的表达量水平。免疫组织化学染色定量左心耳组织TFAM水平。Logistic回归分析AMPK、PGC-1α、NRF1、TFAM的表达水平与术后早期房颤之间的关系。结果 WB结果显示,与窦性心率患者相比,房颤患者左心耳组织内的AMPK、PGC-1α、NRF1、TFAM的表达明显降低（AMPK: 0.75±0.27 VS 0.47±0.43, PGC-1α:0.55±0.10 VS 0.35±0.10, NRF1:0.67±0.11 VS 0.46±0.15, TFAM:0.88±0.19 VS 0.58±0.30,P均<0.05）。免疫组化结果显示房颤患者的左心耳TFAM水平较窦性患者明显降低（8.86±2.13 VS 5.95±2.53, P<0.05）。Logistic回归分析显示TFAM为术后早期房颤的影响因素（b=-0.55, P<0.05）补充数据,低水平TFAM会增加术后新发房颤的风险。结论 AMPK/PGC-1α信号通路参与了房颤过程,其表达在房颤心患者房内降低。TFAM为术后早期房颤的相关因素,低水平TFAM会增加术后发生房颤的风险。     

Sheng-jiang powder ameliorates obesity-induced pancreatic inflammatory injury via stimulating activation of the AMPK signalling pathway in rats

AIM To investigate the mechanisms by which Sheng-jiang powder(SJP) ameliorates obesity-induced pancreatic inflammatory injury.METHODS Sprague-Dawley rats were randomized into three groups: normal group(NG), obese group(HLG), or SJP treatment group(HSG). Obesity was induced by feeding a high-fat diet in the HLG and HSG, while the NG received standard chow. Rats were euthanized after 12 wk, and blood and pancreatic tissues were collected for histopathological analyses. Nuclear factor kappa-light-chain-enhancer of activated B cells(NF-κB) and transforming growth factor beta(TGF-β) expression, serum triglyceride and adiponectin levels, and apoptosis in pancreatic acinar cells were assessed. A high-fat AR42 J acinar cell injury model was established using very low-density lipoprotein(VLDL). AR42 J acinar cell culture supernatant, treated with different interventions, was applied to seven groups of pancreatic stellate cells(PSCs). The proliferation of PSCs and the expression of fibronectin and type I collagenase were assessed.RESULTS Compared with the NG, we found higher pathological scores for pancreatic tissues, lower serum adiponectin levels, higher expression levels of NF-κB in pancreatic tissues and TGF-β in pancreatic inflammatory cells, and increased apoptosis among pancreatic acinar cells for the HLG(P 0.05). Compared with the HLG, we found reduced body weight, Lee's index scores, serum triglyceride levels, and pathological scores for pancreatic tissues; higher serum adiponectin levels; and lower expression levels of NF-κB, in pancreatic tissue and TGF-β in pancreatic inflammatory cells for the HSG(P 0.05). The in vitro studies showed enhanced PSC activation and increased expression levels of fibronectin and type I collagenase after SJP treatment. An adenosine 5‘-monophosphate-activated protein kinase(AMPK) inhibitor inhibited PSC activation.CONCLUSION SJP may ameliorate obesity-induced pancreatic inflammatory injury in rats by regulating key molecules of the adiponectin-AMPK signalling pathway.     

AMPK信号通路及其在感染性疾病中的研究进展

腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)是一种AMP依赖性的蛋白激酶,负责调节细胞能量的合成与分解,是细胞生长、繁殖和自噬的关键调节剂。AMPK及其信号通路在病毒、细菌和寄生虫等感染中发挥了重要作用,有望成为一种药物新靶点。本文将对近年来AMPK信号通路在感染性疾病中的研究展开综述。     

肥胖小鼠脂肪组织缺氧对脂联素表达的转录抑制作用

目的观察缺氧对脂肪细胞脂联素mRNA和蛋白表达的影响,探讨肥胖小鼠脂肪组织缺氧导致脂肪组织脂联素表达下降的机制。方法采用实时定量聚合酶链反应（qRT—PCR）和蛋白免疫印迹法（Western blotting）检测遗传型肥胖小鼠（ob／ob,12周）和高脂饮食肥胖小鼠（HFD,53周）的附睾旁脂肪中脂联素mRNA和蛋白的表达;用小鼠3T3-L1脂肪细胞系为模型,采用RT—PCR和荧光素酶报告基因方法检测缺氧处理后脂联素和过氧化物酶体增殖物激活受体（PPAR）-mRNA的表达和稳定性、脂联素启动子的活性;用Western blotting和荧光素酶报告基因检测缺氧对PPAR-γ在核蛋白中集聚以及PPAR-γ转录因子活性的影响。组间数据比较采用t检验。结果（1）缺氧时两种肥胖小鼠的脂肪组织中脂联素mRNA和蛋白的表达均显著下降（P〈0．01）;333-L1脂肪细胞系在缺氧8h和24h后,脂联素mRNA表达量分别下降至0．65±0．05和0．29±0．05,较对照组（1．00±0．04）明显降低,差异有统计学意义（t=11．548、24．893,均P〈0．01）,但缺氧对脂联素mRNA的稳定性并没有影响;荧光素酶报告基因方法表明,脂联素启动子的活性受到缺氧的抑制。（2）在两种肥胖小鼠的脂肪组织中,PPAR-γmRNA和蛋白的表达均明显下降（P〈0．01）;小鼠333-L1脂肪细胞系在缺氧8h和24h后,PPAR- γmRNA的表达量分别下降至0．72±0．09和0．54±0．07,与对照组（1．00±0．09）相比,差异有统计学意义（t：5．134、9．876,均P〈0．01）;PPAR一1蛋白的核转位以及PPAR一^y转录因子活性也受到缺氧的抑制。结论肥胖小鼠脂肪组织缺氧抑制了脂联素的表达,抑制作用可能发生在转录水平;其机制可能是通过抑制PPAR-γmRNA的表达和PPAR-γ转录因子的活性而实现的。     

抵抗素对内皮细胞一氧化氮生成的影响及其AMPK信号机制

目的研究抵抗素对人脐静脉内皮细胞（HUVEC）一氧化氮生成的影响及其信号机制。方法不同浓度人抵抗素（0-100ng／ml）干预HUVEC24h。DAF-2DA染色,激光共聚焦显微镜观察各组一氧化氮生成改变,Western-Blot检测各组eNOS、AMPK磷酸化水平改变。结果15、50、100ng／ml抵抗素干预HUVEC24h后,3组的一氧化氮生成分别为4．014-0．69、3．76±0．71、3．73±0．45,与对照组一氧化氮生成（4．89±0．58）相比显著降低（P〈0.05）;50ng／ml组添加AMPK特异激动剂A／CAR后,一氧化氮生成（5．08±0．70）显著升高（P〈0.01）。各抵抗素干预组的AMPK和eNOS磷酸化水平均明显降低;而添加AMPK特异激动剂AICAR后,伴随AMPK的激活,eNOS磷酸化水平也显著增高（P〈0．05）。结论抵抗素在内皮细胞可通过对AMPK的抑制进而导致eNOS失调,降低内皮一氧化氮的生成。     

Age-related changes in human left and right atrial conduction

INTRODUCTION: Advancing age is an independent risk factor for atrial fibrillation (AF), which is considered to be initiated by ectopic triggers and maintained by an arrhythmogenic substrate. It is not known whether substrate changes produce this age-related increase in propensity toward AF. We addressed the hypothesis that advancing age is associated with changes in biatrial electrophysiology even in patients with no history of atrial arrhythmias. METHODS AND RESULTS: Patients with left-sided accessory pathways and requiring routine electrophysiological studies were recruited. Electroanatomic mapping was performed in the left and right atria of 23 patients (age ranging from 17 to 75 years) with structurally normal hearts and no history of AF during sinus rhythm and pacing. Unlike previous studies, a trigonometric method was used to quantify wavefront propagation velocities (WPV) precisely in the direction of propagation. Refractoriness was measured at 2 cycle lengths, at three different atrial sites. Both right (r =-0.77, P < 0.0001) and left (r =-0.79, P < 0.001) atrial WPV demonstrated strongly inverse correlation with age. Furthermore, left and right WPVs were highly correlated (r = 0.66, P < 0.01), with velocities being 6.4 +/- 2.2 cm/sec higher in the right atria (P < 0.01). Refractoriness was significantly correlated with increasing age only at the septum (r = 0.53, P < 0.01). Left atrial wavelength was inversely correlated with increasing age (r =-0.56, P = 0.03). P wave duration was associated with age (r = 0.42, P = 0.04) and left atrial size (r = 0.44, P = 0.04) but not atrial WPV. CONCLUSION: Aging human atria demonstrate progressive decline in WPV and increase in septal refractoriness. These age-related changes in biatrial electrophysiology are likely to be important factors in the age-related increase in AF prevalence.     

肥胖者网膜脂肪组织中脂联素、肿瘤坏死因子α mRNA表达及其与胰岛素抵抗相关性的研究

19例肥胖者和24例非肥胖者的网膜脂肪研究显示，肥胖者脂联素（APN）基因表达降低，肿瘤坏死因子α（TNF-α）基因表达增加，两者表达呈负相关。肥胖、胰岛素抵抗为网膜脂肪APN、TNF-α基因表达的独立影响因素。     

风湿性心脏病慢性心房颤动患者右心耳肝细胞生长因子及其受体的表达

目的观察风湿性心脏病慢性心房颤动(简称房颤)患者右心耳肝细胞生长因子(HGF)及受体(c-Met)表达的变化。方法将术中获取右心耳的27例风湿性瓣膜病患者分为2组,其中窦性心律(简称窦律)组8例,慢性房颤组19例,另选先天性心脏病患者8例(均为窦律)作为对照组,以β-肌动蛋白(β-actin)为内参照基因,采用实时荧光定量聚合酶链式反应(RealtimePCR)技术测定心房组织中HGF、c-MetmRNA的含量,用免疫组织化学方法评价HGF及c-Met的蛋白表达情况。结果与对照组和窦律组比较,慢性房颤组HGF表达显著下降(P<0.01)。而风心窦律组与对照组无差异。c-MetmRNA的表达三组无差异。结论慢性房颤患者心房组织HGF的表达显著降低,而其受体c-Met在房颤患者心房组织中未见明显变化。     

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.     

Ischemia-related changes of fat-mass and obesity-associated protein expression in the gerbil hippocampus

Metabolic Brain Disease - Fat-mass and obesity-associated protein (Fto) plays important roles in energy metabolism. It also acts as a demethylase and is most abundantly found in the brain. In the...     

脂联素mRNA在肥胖症患者腹部皮下与网膜脂肪组织中表达水平的研究

目的探讨肥胖症患者腹部皮下脂肪组织与大网膜脂肪组织脂联素的表达水平及与BMI、WHR、血脂、胰岛素敏感性的关系。方法用半定量RT-PCR方法检测19例肥胖症患者(BMI≥25·0kg/m2)和28例非肥胖症患者(BMI<25·0kg/m2)腹部皮下与大网膜脂肪组织脂联素mRNA的表达水平,并测量BMI、WHR、BP,FPG、FIns、血脂和胰岛素抵抗指数(HOMA-IR)。结果(1)肥胖组大网膜脂肪组织脂联素mRNA表达水平显著低于非肥胖组(P<0·05),肥胖组大网膜脂肪组织脂联素mRNA水平显著低于皮下脂肪组织(P<0·05)。(2)肥胖组FIns、HOMA-IR、BP、TG与VLDL-C均高于非肥胖组(P<0·05~P<0·01)。(3)非肥胖组中网膜脂肪组织脂联素mRNA表达量与BMI(r=-0·513,P<0·05)、VLDL-C(r=-0·733,P<0·01)显著负相关。结论肥胖症患者网膜脂肪组织脂联素mRNA表达水平显著降低,它可能在肥胖相关的代谢综合征的发病中起一定作用。     

Postconditioning protects human atrial muscle through the activation of the RISK pathway

Ischemic postconditioning (IPost) has been demonstrated to reduce myocardial injury in patients undergoing primary coronary angioplasty for an acute myocardial infarction.Pre-clinical animal studies suggest that pro-survival protein kinases of the Reperfusion Injury Salvage Kinase (RISK) pathway such as Akt and Erk1/2 mediate the cardioprotective effect of IPost.Whether IPost can protect human myocardial tissue ex vivo and whether it recruits the RISK pathway in human myocardium are both not known. To investigate this, atrial appendages were harvested from patients undergoing cardiac surgery. From these samples atrial trabeculae were isolated and mounted on a superperfusion apparatus and subjected to 90 min of hypoxia followed by 120 min of reoxygenation at the end of which function expressed as a percentage of the recovery of baseline contractile function was determined.Atrial trabeculae were randomized to control, hypoxic preconditioning (HPre), hypoxic postconditioning comprising either four 30-s (HPost-30) or 60-s (HPost-60) episodes of alternating hypoxia and reoxygenation, and HPost in the presence or absence of UO126 (a MEK1/2 inhibitor) or LY294002 (a PI3K inhibitor).HPre and HPost-60 improved the recovery of baseline contractile function (45.4±3.2% with HPre and 45.2±2.2% with HPost-60 vs 26.7±2.1 % in control: N≥ 6/group: P<0.05), whereas HPost-30 failed to cardioprotect (28.3±3.4% with HPost-30 vs 26.7±2.1 % in control: N≥ 6/group: P>0.05). The cardioprotective effect of HPost-60 was abolished in the presence of either LY (28.1±2.5% with HPost-60+LY vs 45.2±2.2% with HPost-60: N≥ 6/group: P<0.05) or UO (32.7±1.8% with HPost-60+UO vs 45.2±2.2% with HPost-60:N=7/group: P<0.05). The kinase inhibitors alone had no effect on functional recovery (28.2±3.6% with LY and 30.1±4.8% with UO vs 26.7±2.1 % in control: N≥ 5/group: P>0.05). In conclusion, we demonstrate for the first time that postconditioning protects human myocardium ex vivo and that this effect is dependent on the activation of the RISK pathway.     

风湿性心脏瓣膜病心房颤动患者心房结构重构及胶原的表达

目的检测风湿性心脏瓣膜病心房颤动患者心房结构重构及胶原的表达,探讨胶原在心房结构重构中的意义。方法选择行开胸心脏手术的风湿性心脏瓣膜病患者39例,将持续性心房颤动患者24例为房颤组,窦性心律患者15例为窦律组。取患者心房组织标本,应用HE染色及Masson染色进行组织学检查;免疫组织化学法检测心房组织中Ⅰ型、Ⅲ型胶原蛋白的表达。结果房颤组患者较窦律组左心房内径明显增大。房颤组患者心房有肌溶解、心肌肥厚及广泛间质纤维化的改变。与窦律组比较,房颤组患者的左、右心房组织胶原容积分数均明显增大,左、右心房Ⅰ型胶原蛋白的表达明显增加(P0.05),而Ⅲ型胶原蛋白表达无明显差异(P0.05)。结论心房颤动患者心房结构发生明显的病理改变,其中心房间质纤维化为主要特征,左心房改变最为明显。     

Anatomical diversity and age-related histological changes in the human right atrial posterolateral wall.

AIMS: Recent clinical observations suggest that the right atrial posterolateral wall structures originate ectopic beats and function as anatomical obstacles. Because atrial arrhythmias increase in incidence after middle age, we investigated histological diversity and age-related changes in right atrial posterolateral wall. METHODS AND RESULTS: Twenty-six autopsied hearts (mean 65.2 years, 16 men and 10 women) were studied. The entire posterolateral right atrium was cut serially. We determined the distribution of the sinoatrial node and localized it in relation to the crista terminalis and sinus venosus. We also compared histopathological changes in these tissues between three groups consisting of 31- to 50-year-old, 51- to 70-year-old and 71- to 90-year-old hearts. Total mean length of the crista terminalis, the sinoatrial node, and the sinus venosus was 46 mm, 21 mm and 29 mm, respectively, and showed no age-related changes, but the distribution of the sinoatrial node was varied. Mean muscular volume of the sinus venosus was significantly reduced in the two older groups, though that of the crista terminalis showed no age related-changes. CONCLUSION: Histological diversity of the sinoatrial node and age-related changes in the sinus venosus beneath the sinoatrial node may enhance histological heterogeneity and hence arrhythmogenicity.     

Epicardial right atrial free wall mapping in chronic atrial fibrillation: Documentation of repetitive activation with a focal spread--a hitherto unrecognised phenomenon in man

BACKGROUND: Previous studies have shown that atrial fibrillation of recentonset in man is based on a varying number of simultaneouslypresent activation waves re-entering either themselves or eachother. In the present study, right atrial activation duringchronic atrial fibrillation in man was studied. METHODS AND RESULTS: In 16 patients with chronic atrial fibrillation multiple epicardialrecordings of 8 s each were made at the right atrial posteriorfree wall and at the appendage using a 20x35 mm electrode arraywith 56 bipolar measurement points. The preferable activationpattern of each recording and the propagation direction, cyclelength and conduction velocity of individual activation waveswithin each recording were determined. Activation was characterizedby unorganised activation with several simultaneously presentactivation waves: inconsistent preferable activation pattern(n=5), predominantly organised activation with either frequentepisodes of uniform activation; consistent preferable activationpattern (n=7) or frequent episodes of activation with focalspread; focal preferable activation pattern (n=4). Random re-entrywas frequently documented in recordings with the inconsistentpreferable activation pattern and less frequently in recordingswith the consistent and focal preferable activation pattern.Complete re-entry circuits were rarely documented. The medianfibrillation cycle length was 146, 159 (P<0·05) and165 ms (not significant) and the mean conduction velocity duringuniform activation was 64, 67 and 83 cm.s^–1 (not significant)in recordings with the inconsistent, consistent and focal preferableactivation pattern, respectively. CONCLUSIONS: During chronic atrial fibrillation in man, right atrial freewall activation ranges from disorganised activation with multipleco-existing activation waves to predominantly organised activationcharacterized by either uniform activation consistent with thepresence of large re-entry circuits or repetitive activationof unknown mechanism and focal spread.     

Melatonin regulates the activities of ovary and delays the fertility decline in female animals via MT1/AMPK pathway

Female fertility irreversibly declines with aging, and this is primarily associated with the decreased quality and quantity of oocytes. To evaluate whether a long‐term of melatonin treatment would improve the fertility of aged mice, different concentrations of melatonin (10^?3, 10^?5, 10^?7 mol/L) were supplemented into drinking water. Melatonin treatments improved the litter sizes of mice at the age of 24 weeks. Mice treated with 10^?5 mol/L melatonin had the largest litter size among other concentrations. At this optimal concentration, melatonin not only significantly increased the total number of oocytes but also their quality, having more oocytes with normal morphology that could generate more blastocyst after in vitro fertilization in melatonin (10^?5 mol/L)‐treated group than that in the controls. When these blastocysts were transferred to recipients, the litter size was also significantly larger in melatonin treated mice than that in controls. The increases in TAOC and SOD level and decreases in MDA were detected in ovaries and uterus from melatonin‐treated mice compared to the controls. Melatonin reduced ROS level and maintained mitochondrial membrane potential in the oocytes cultured in vitro. Mechanistically studies revealed that the beneficial effects of melatonin on oocytes were mediated by MT1 receptor and AMPK pathway. Thereafter, MT1 knocking out (MT1‐KO) were generated and shown significantly reduced number of oocytes and litter size. The expression of SIRT1, C‐myc, and CHOP were downregulated in the ovary of MT1‐KO mice, but SIRT1 and p‐NF‐kB protein level were elevated in response to disturbed redox balance. The results have convincingly proven that melatonin administration delays ovary aging and improves fertility in mice via MT1/AMPK pathway.     

肥胖患者大网膜脂肪脂联素mRNA表达及相关因素的研究

选择43例择期外科手术患者，用RT-PCR法检测大网膜脂肪组织脂联素表达水平。发现肥胖患者的大网膜脂肪组织中脂联素表达明显降低，腹型肥胖、胰岛素抵抗以及肿瘤坏死因子-α是大网膜脂肪组织脂联素表达水平的主要影响因素。     

Association of the adiponectin rs266729 C>G variant and coronary heart disease in the low risk 'Golden Years' type 1 diabetes cohort

The C-allele of rs266729 is associated with CHD, while the G-allele of rs17300539 is associated with metabolic traits. We examined these in type 1 diabetes. For rs266729, the C-allele was associated with 8-fold increase in CHD. For rs17300539, the G-allele was associated with increases in triglycerides and waist circumference.     

AMPK signalling and the control of substrate use in the heart

All mammalian cells rely on adenosine triphosphate (ATP) to maintain function and for survival. The heart has the highest basal ATP demand of any organ due to the necessity for continuous contraction. As such, the ability of the cardiomyocyte to monitor cellular energy status and adapt the supply of substrates to match the energy demand is crucial. One important serine/threonine protein kinase that monitors cellular energy status in the heart is adenosine monophosphate activated protein kinase (AMPK). AMPK is also a key enzyme that controls multiple catabolic and anabolic biochemical pathways in the heart and indirectly plays a crucial role in regulating cardiac function in both physiological and pathophysiological conditions. Herein, we review the involvement of AMPK in myocardial fatty acid and glucose transport and utilization, as it relates to basal cardiac function. We also assess the literature amassed on cardiac AMPK and discuss the controversies surrounding the role of AMPK in physiological and pathophysiological processes in the heart. The work reviewed herein also emphasizes areas that require further investigation for the purpose of eventually translating this information into improved patient care.