A potential cardioprotective role of hepatocyte growth factor in myocardial infarction in rats

OBJECTIVE: Cardiotrophic growth factors with anti-cell death actions on cardiac myocytes have gained attention for treatment of patients with myocardial infarction. Hepatocyte growth factor (HGF) plays a role in tissue repair and protection from injuries, however, the physiological role of HGF in the myocardium has not been well defined. We asked if HGF would afford to the infarcted myocardium. METHODS AND RESULTS: Mature cardiac myocytes prepared from adult rats expressed barely detectable levels of the c-Met/HGF receptor, however, c-Met receptor expression increased during cultivation, which meant that cardiac myocytes are potential targets of HGF. Addition of hydrogen peroxide remarkably decreased the number of viable mature cardiac myocytes in primary culture, whereas treatment with HGF enhanced survival of the cells subjected to the oxidant stress. Although very low levels of c-Met/HGF receptor and HGF mRNA expression were seen in normal rat hearts, both c-Met/HGF receptor and HGF mRNA levels rapidly increased to much higher levels than normal, when the rats were subjected to myocardial infarction. Immunohistochemical analysis of the c-Met receptor indicated that this receptor was expressed in cardiomyocytes localized in the border regions of the viable myocardium and in non-infarcted regions following myocardial infarction. CONCLUSION: The c-Met/HGF receptor is induced in cardiomyocytes following myocardial infarction and HGF exhibits protective effect on cardiomyocytes against oxidative stress. Our working hypothesis is that HGF may afford myocardial protection from myocardial infarction.     

Elevation of vascular endothelial growth factor-A serum levels following acute myocardial infarction. Evidence for its origin and functional significance

Following the onset of acute myocardial infarction (AMI), a number of serum parameters show well-defined changes reflecting myocardial injury. During the consecutive repair phase, compensatory processes are initiated including the formation of a collateral circulation on the basis of angiogenesis and arteriogenesis. An important angiogenic factor is vascular endothelial growth factor-A (VEGF-A), shown to be upregulated in the ischemic myocardium. It is unclear, however, whether acute myocardial ischemia leads to a detectable elevation of VEGF-A serum concentrations. With the use of an immunoradiometric assay, we measured the levels of VEGF-A in the serum of patients after AMI at defined time intervals, of patients with unstable angina pectoris (UAP) and of healthy individuals. In addition, in a small group of patients with subacute myocardial infarction VEGF-A concentrations were measured in coronary sinus blood. The data are given as median followed by the 25th and 75th percentiles. In the group with AMI serum VEGF-A measured 105 [78; 176] pg/ml on day 1 and 114 pg/ml [72; 163] pg/ml on day 3 after onset of AMI. Serum levels of VEGF-A significantly increased on day 7 after AMI to 189 [119; 373] pg/ml (P=0.0103) and on day 10 to 255 [162; 371] pg/ml (P=0.0007). The VEGF-A serum level in healthy controls and in patients with UAP measured 98 [75; 137] pg/ml and 116 [57; 140] pg/ml, respectively. Serum at day 10 after AMI contained VEGF-A at a biologically relevant concentration capable of stimulating proliferation of endothelial cells. Surprisingly, VEGF-A serum levels were similar in samples taken from the coronary sinus with 61 [43; 83] pg/ml. Therefore the main source for VEGF-A in the blood stream is not the infarcted myocardium. However, the number of platelets, a rich source of VEGF-A, is significantly increased after myocardial infarction, i.e. 284 [252; 363] x 10(9)/litre v 220 [177; 250] x 10(9)/litre. In conclusion, the time course of VEGF-A elevation following AMI strongly suggests that VEGF-A plays a role as an endogenous activator of coronary collateral formation in the human heart. The most likely source of the elevated VEGF-A are platelets, rather than the infarcted myocardium.     

Effect of hepatocyte growth factor on left ventricular remodeling after acute myocardial infarction in canine

Background and objectives To investigate the effect of hepatocyte growth factor (HGF) on left ventricular (LV) remodeling after acute myocardial infarction (AMI). Methods AMI was produced by ligation of proximal left anterior descending coronary artery(LAD) in 12 mongrel canines. These animals were randomized into 2 groups. In HGF group (n=6), canines were injected with pcDNA3-HGF lml (about 300ug) at the margin of infarcted myocardium; in control group (n=6) canines were injected with equal volume of normal saline. Cardiac function and left ventricular remodeling were evaluated with echocardiography at 1, 4, 8 weeks after MI. LV myocardium specimens were obtained at 8 weeks and stained with hematoxylin and eosin for histological examination or with sirius red to assess the collagen content. Results Compared with control group, LVEF in HGF group was significantly higher at 4 weeks (49.61+6.66 vs 39.84+6.39; P＜0.05) and at 8 weeks (51.57+8.53 vs 40.61+7.67; P＜0.05) after AMI, while LVESV was significantly lower in HGF group than that in control group at 8 weeks after AMI (18.98+3.47 vs 25.66+5.86; P＜0.05). Posterior left ventricular wall thickness decreased significantly from 1 wk to 8 wks after AMI in control group, while remained unchanged in HGF group. Compared with control group, histological examination showed more neovascularization and less scar, and sirius red staining indicated higher volume of type Ⅲ collagen (7.10±4.06% vs 3.77±1.09%; P＜0.05) and lower collagen Ⅰ/Ⅲ ratio value (1.11±0.52 vs 2.94±2.48; P＜0.05)in HGF group. Conclusion HGF gene transfer might improve cardiac function and LV remodeling after acute myocardial infarction by stimulating angiogenesis, reducing fibrosis, and reducing myocardial scarring.     

Hepatocyte growth factor production may be related to the inflammatory response in patients with acute myocardial infarction.

Hepatocyte growth factor (HGF) is a well-known powerful proliferative factor of vascular endothelial cells and it has been reported that plasma HGF concentrations are increased in acute myocardial infarction (AMI), although the mechanisms are not yet well delineated. Serum HGF levels and C-reactive protein (CRP) were measured in 22 patients with unstable angina pectoris (UAP) (15 males, 7 females; class IIb or IIIb of the Braunwald classification), 60 patients with AMI (37 males, 23 females; average time from the onset of symptoms to admission 4.6+/-0.7h, range, 0.5-12h), and 20 normal subjects. Immediate angioplasties were performed in 51 patients with AMI, and the time course of the HGF levels were measured in 31 patients among them. Heparin dramatically increased the HGF level and it declined to the normal range 18h after heparin injection. Blood samples were taken before heparin treatment, or at least 24h after. Serum HGF levels on admission was significantly increased in UAP (mean+/-SE: 0.30+/-0.03ng/ml, p<0.01), and AMI (0.27+/-0.02ng/ml, p<0.01) compared with the normal subjects (0.19+/-0.01 ng/ml). Even in the early stage (within 3 h of onset of symptoms to admission, average time was 1.8+/-0.1 h), serum HGF levels were already elevated (0.25+/-0.02 ng/ml, p<0.05). There was no significant difference between the HGF levels in UAP and AMI. Fifty-one of the 60 patients with AMI underwent immediate percutaneous transluminal coronary angioplasty and blood samples were obtained from 31 of them on days 7, 14, and 21 after MI. Serum HGF levels peaked on day 7 (0.34+/-0.04ng/ml, p<0.01) and there was a weak relationship between peak creatine kinase and serum HGF levels at that time. A statistically significant correlation was found between peak CRP and serum HGF levels on day 7 (r=0.62: p<0.001). Serum HGF levels decreased to nearly normal by day 21 (0.22+/-0.01 ng/ml). The study shows that serum HGF levels during the early stage of AMI increased significantly and peaked by day 7 after the onset, at which time there was a strong correlation with peak CRP levels. These data suggest that HGF production may be related to the inflammatory response in AMI.     

Serum hepatocyte growth factor predicts ventricular remodeling following myocardial infarction.

Hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) stimulate endothelial cell proliferation and induce angiogenesis, but the timing and significance of their release in patients with acute myocardial infarction (AMI) are unknown in relation to future left ventricular remodeling. Venous blood samples were obtained at admission and up to 3 weeks later in 40 patients with AMI and in 40 age- and sex-matched control subjects. Blood samples were also taken from the coronary sinus (CS) in 20 patients on day 7 following AMI. Left ventricular end-diastolic volume in the subacute (1 week) and chronic (3 months) phases was assessed by left ventriculography to identify the remodeling group (n=15), which was defined as an increase in left ventricular end-diastolic volume index > or =5 ml/m(2) relative to the baseline value. Serum HGF and VEGF concentrations were higher in newly admitted patients with AMI than in the controls (HGF, 0.33 +/-0.09 vs 0.24+/-0.08 ng/ml, p<0.01; VEGF, 92.2+/-43.1 vs 67.2+/-29.8 pg/ml, p<0.01), peaking on day 7 (HGF, 0.41+/-0.12; VEGF, 161.7+/-76.9), and gradually decreasing between days 14 and 21. The HGF concentration in the CS did not differ from the concentration in the periphery, but the VEGF concentration was significantly more abundant in the CS than in the peripheral sample on day 7 (p<0.05). The serum HGF concentration on day 7 was higher in the remodeling group than in the nonremodeling group (0.47 +/-0.13 vs 0.36+/-0.09 ng/ml, p<0.01), but there was no difference between the groups on admission, day 14 and day 21. The serum VEGF concentration did not differ between the remodeling and nonremodeling groups at any time. Thus, the serum HGF concentration on day 7 after AMI is mostly from noncardiac sources and predicts left ventricular remodeling.     

Serial changes in serum VEGF and HGF in patients with acute myocardial infarction

The time course of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) release in patients with acute myocardial infarction (AMI) is unknown. Blood samples were obtained at the time of admission and 3, 7, 14 and 21 days later in 32 patients with AMI and 30 control patients. Serum VEGF and HGF, as well as C-reactive protein (CRP) and amyloid A protein (SAA), were determined. Both serum VEGF and HGF levels on admission in patients with AMI were higher than control values and peaked on day 7. VEGF levels in patients with preinfarction angina were higher than in patients with no preinfarction angina, whereas the HGF level did not differ. Both CRP and SAA levels peaked on day 3, and the CRP level on day 3 correlate with both VEGF and HGF levels on day 7. We hypothesized that the serum VEGF level is associated with preinfarction ischemia and the increase in VEGF and HGF on day 7 of AMI may represent a response to acute inflammation.     

骨髓干细胞介导的人肝细胞生长因子基因转染在兔心肌梗死组织中的表达

目的:观察以骨髓干细胞(BMSCs)介导的人肝细胞生长因子(hHGF)基因转染在兔心肌梗死组织中能否稳定表达.方法:家兔16只,复制急性心肌梗死(AMI)模型.随机分为2组:移植组:BMSCs加hHGF移植,对照组.另外随机选取8只兔作为假手术组.AMI术后3 d,抽取股骨骨髓1.5 ml,分离BMSCs培养.于对数生长期加入5-溴脱氧尿苷孵育24 h,以标记移植细胞.构建pcDNA3.1-hHGF重组表达载体,移植前用脂质体包裹表达载体转染BMSCs,孵育24 h.AMI术后14 d,行自体细胞移植,对照组接受等量的无血清培养基注射,假手术组只开胸,不注射.细胞移植后28 d,检测左心室血流动力学指标;取心肌组织,RT-PCR检测hHGFmRNA的表达;酶联免疫吸附法(ELISA)测定心肌组织中HGF的含量.结果:与假手术组比较,心肌梗死后28d,对照组左心室功能降低,但BMSCs加hHGF组左心心室功能有改善;RT-PCR结果显示移植组有hHGFmRNA表达,ELISA测定HGF含量移植组高于对照组.结论:AMI组织中HGF含量降低,转染HGF的BMSCs能在AMI组织中生存并能表达分泌HGF,其左心室功能有改善.     

Hepatocyte growth factor prevents ventricular remodeling and dysfunction in mice via Akt pathway and angiogenesis

This study determines the effect of hepatocyte growth factor (HGF) on post-infarction left ventricular (LV) remodeling and cardiac function. In mice, on day 1 after myocardial infarction (MI), HGF (0.45 mg/kg per day) was injected into the tail vein for 7 days (n = 12). In the control mice (n = 12), 0.9% sodium chloride was injected instead of HGF. Hemodynamic data were obtained in vehicle treated control and HGF-treated hearts 4 weeks after the onset of MI. In the HGF-treated group, cardiac function was well preserved as indicated by LV pressure-volume relationship. These mice exhibited better LV systolic and diastolic function. The infarcted LV wall in HGF-treated heart was thicker as compared to vehicle treated group. Fibrosis and infarct size of the ventricular wall was significantly reduced in the HGF-treated hearts. 5-Bromo-2'-deoxy-uridine (BrdU) and Ki67 positive cardiomyocytes were observed in the border area of the HGF-treated infarcted hearts. c-Met and c-kit positive cardiomyocytes were observed in the border area and epicardium. Angiogenesis was significantly enhanced in HGF-treated hearts as determined by vessel density per unit area. A significant reduction in apoptosis in the HGF-treated hearts was observed compared with control hearts, and was strongly associated with increased Akt activation. Treatment with HGF improved heart function through angiogenesis, ventricular wall thickening, and hypertrophy of cardiomyocytes. The antiapoptotic effect of HGF was mediated by activation of PI3-kinase/Akt pathway.     

PCI术后AMI患者非梗死区冠脉血流储备的变化及其对左室功能的影响

目的 观察和分析急性心肌梗死（AMI）患者PCI术后非梗死区冠脉血流储备（CFR）的变化及其对左室功能的影响。方法 22名AMI患者PCI术后1周行二维超声心动图和多巴酚丁胺负荷实时心肌声学造影（MCE）检查,测量左室功能和梗死区、非梗死区CFR,比较非梗死区CFR与梗死区及正常对照组CFR;根据非梗死区CFR值将患者分为两组,比较两组远期左室功能的变化。结果 非梗死区CFR值与正常对照组相比明显下降,非梗死区CFR与左室舒张末期容积呈负相关。结论 AMI后非梗死区心肌同样存在微循环功能障碍,非梗死区CFR值能预测AMI后远期左室功能。     

Activation of Notch-mediated protective signaling in the myocardium

The Notch network regulates multiple cellular processes, including cell fate determination, development, differentiation, proliferation, apoptosis, and regeneration. These processes are regulated via Notch-mediated activity that involves hepatocyte growth factor (HGF)/c-Met receptor and phosphatidylinositol 3-kinase/Akt signaling cascades. The impact of HGF on Notch signaling was assessed following myocardial infarction as well as in cultured cardiomyocytes. Notch1 is activated in border zone cardiomyocytes coincident with nuclear c-Met following infarction. Intramyocardial injection of HGF enhances Notch1 and Akt activation in adult mouse myocardium. Corroborating evidence in cultured cardiomyocytes shows treatment with HGF or insulin increases levels of Notch effector Hes1 in immunoblots, whereas overexpression of activated Notch intracellular domain prompts a 3-fold increase in phosphorylated Akt. Infarcted hearts injected with adenoviral vector expressing Notch intracellular domain treatment exhibit improved hemodynamic function in comparison with control mice after 4 weeks, implicating Notch signaling in a cardioprotective role following cardiac injury. These results indicate Notch activation in cardiomyocytes is mediated through c-Met and Akt survival signaling pathways, and Notch1 signaling in turn enhances Akt activity. This mutually supportive crosstalk suggests a positive survival feedback mechanism between Notch and Akt signaling in adult myocardium following injury.     

Changes of serum hepatocyte growth factor in coronary artery disease

Hepatocyte growth factor (HGF) is an endothelial cell specific growth factor involved in the repair of endothelial cells and collateral formation, however, the role for coronary artery disease is still unknown. We measured serum HGF level in various coronary artery diseases to examine the clinical significance. Serum HGF level was measured using the enzyme-linked immunosorbent assay method in patients with stable effort angina pectoris (n = 26), old myocardial infarction (n = 18), unstable angina pectoris (UAP; n = 10) and acute myocardial infarction (AMI; n = 21). As a control group, we selected 11 patients with neurocirculatory asthenia. Blood samples from peripheral veins were collected at cardiac catheterization before heparin administration. In the AMI group, blood samples were also collected at 48, 72 hr, 1, 2, 3 and 4 weeks from the peripheral veins and 48 and 72 hr after reperfusion from the coronary sinus. Serum HGF level was significantly higher in the UAP (0.41 +/- 0.12 ng/ml, p < 0.001) and AMI groups (0.38 +/- 0.26 ng/ml, p < 0.05) compared to the control group (0.19 +/- 0.09 ng/ml). Serum HGF level peaked 48 hr after reperfusion in both the peripheral veins (0.42 +/- 0.16 ng/ml) and coronary sinus (0.58 +/- 0.23 ng/ml) in the AMI group, with a significantly higher level in the coronary sinus than the peripheral veins (p < 0.05). No significant correlation between peak HGF level in the peripheral veins and peak creatine kinase (CK), CK-MB, ejection fraction and cardiac index was observed. Serum HGF was elevated in acute coronary syndrome, indicating advanced endothelial cell damage. HGF is produced, at least partially, in the heart in patients with AMI. Serum HGF level may be useful to detect endothelial cell damage rather than myocardial cell damage.     

Hepatocyte growth factor ameliorates the progression of experimental autoimmune myocarditis: a potential role for induction of T helper 2 cytokines

Hepatocyte growth factor (HGF) plays a role in cell protection, antiapoptosis, antifibrosis, and angiogenesis. However, the role of HGF in the immune system is not well defined. We examined the influence of HGF on T cells and the effects of HGF therapy in acute myocarditis. Lewis rats were immunized on day 0 with cardiac myosin to establish experimental autoimmune myocarditis (EAM). Human HGF gene with hemagglutinating virus of the Japan-envelope vector was injected directly into the myocardium on day 0 or on day 14 (two groups of treated rats). Rats were killed on day 21. Expression of c-Met/HGF receptor in splenocytes and myocardial infiltrating cells was confirmed by immunohistochemical staining or FACS analysis. Myocarditis-affected areas were smaller in the treated rats than in control rats. Cardiac function in the treated rats was markedly improved. An antigen-specific T cell proliferation assay was done with CD4-positive T cells isolated from control rats stimulated with cardiac myosin. HGF suppressed T cell proliferation and production of IFN-gamma and increased production of IL-4 and IL-10 secreted from CD4-positive T cells in vitro. Additionally, TUNEL assay revealed that HGF reduced apoptosis in cardiomyocytes. HGF reduced the severity of EAM by inducing T helper 2 cytokines and suppressing apoptosis of cardiomyocytes. HGF has potential as a new therapy for myocarditis.     

急性心肌梗塞病人肝细胞生长因子的产生

目的     

抗心肌肌凝蛋白抗体亲大鼠梗塞心肌特性的研究

目的　探讨抗心肌肌凝蛋白单克隆抗体 (antimyosinantibody ,AMA)亲梗塞心肌的特点。方法　心肌梗死大鼠静脉注射放射性锝 99m标记的抗心肌肌凝蛋白单克隆抗体 (99mTc AMA) ,观察注射时间 ,梗死时间和梗塞区对梗塞心肌摄取AMA的影响。结果　注射后 2h梗塞心肌开始摄取AMA ,以后摄取逐渐增加 ,2 4h达到高峰。心肌梗死后 2 0d ,梗塞心肌持续摄取AMA ,期间心肌梗死后 1～ 5d摄取最强 ,梗塞中央区以及梗塞区内层摄取强于其他梗塞区域。结论　急性心肌梗死大鼠梗塞心肌特异性地摄取AMA ,注射AMA后摄取迅速、持久 ,受心肌梗死时间影响较小 ,梗塞中央区内层心肌摄取最强 ,AMA具有亲梗塞心肌的特性。     

Early Anti-inflammatory and Pro-angiogenic Myocardial Effects of Intravenous Serelaxin Infusion for 72 H in an Experimental Rat Model of Acute Myocardial Infarction

Sprague Dawley rats were subjected to acute myocardial infarction (AMI) by permanent ligation of the left anterior descending coronary artery. At the time of AMI, a subcutaneous mini-osmotic pump was implanted and animals were randomized into three groups, according to the intravenous therapy received during the first 72 h: placebo-treated (saline), serelaxin10-treated (SRLX10 = 10 μg/kg/day), or serelaxin30-treated (SRLX30 = 30 μg/kg/day). Treatment with SRLX30 reduced the expression of inflammatory cytokines and chemokines, as well as the infiltration of macrophages, and increased the expression of pro-angiogenic markers and vessel density in the infarcted myocardium after 7 days. SRLX30 did not reduce early myocardial fibrosis but reduced myocardial levels of sST2 and galectin-3. No significant effects were observed with SRLX10 treatment. A significant correlation was observed between plasma levels of serelaxin and effect measures. The results suggest serelaxin has a protective effect in early processes of cardiac remodeling after AMI.     

Clinical significance of serum HGF and c-Met expression in tumor tissue for evaluation of properties and treatment of hepatocellular carcinoma

BACKGROUND/AIMS: To develop a prognostic marker for evaluation of intrahepatic metastasis (IM) of hepatocellular carcinoma (HCC), the ligand-stimulated receptor activity of c-Met due to hepatocyte growth factor (HGF) was estimated. METHODOLOGY: For specimens from 30 HCC patients, who were operated on at the Department of Surgical Oncology, Gifu University School of Medicine, for 2 recent years, the induction value of HGF and c-Met were estimated by western blot. RESULTS: Firstly, the serum HGF levels were significantly higher in invasive gross type or in IM-positive tumors. Secondly, the mean expression value of HGF protein in tumors was 0.56 +/- 0.35, which was not different from non-tumor tissue, 0.59 +/- 0.40. And there was no significant differences based on tumor profiles. Thirdly, the value of c-Met in tumor tissue, 1.36 +/- 0.12, was clearly higher than in non-tumor tissue, 1.07 +/- 0.06. The c-Met expressions were significantly higher in the invasive type of HCC as determined by gross type, vessel invasion, IM presence and histological type. Finally, in individual studies about the relationship between the level of serum HGF and c-Met expression in tumor tissue, the presence of IM could be easily detected. Furthermore, the level of serum HGF after hepatectomy was significantly higher than the preoperative value, and individual studies with c-Met expression were associated with early recurrence. CONCLUSIONS: The induction of c-Met might be important to evaluate the progression of HCC, especially to caution for the presence of IM.     

miR-126及VEGF在大鼠心肌梗死交界区表达的动态变化

目的 观察大鼠心肌梗死(MI)后MI交界区微小RNA-126(miR-126)及血管内皮生长因子（VEGF）表达的动态表达变化,初步探讨miR-126及VEGF对缺血局部血管新生的影响。方法 雄性SD大鼠结扎冠状动脉左前降支建立急性心肌梗死模型组(AMI组),另设假手术对照组(Sham组),每组30只。于术后7 d、14 d和28 d分别处死10只大鼠,进行MI面积百分比测定,实时荧光定量PCR法检测心梗交界区miR-126、VEGF mRNA表达水平,免疫组织化学方法检测各组大鼠MI交界区VEGF蛋白的表达。结果 Sham组术后7 d、14 d和28 d心肌组织 miR-126 mRNA和VEGF mRNA的表达均无明显区别,AMI组术后7 d、14 d和28 d,MI交界区mir-126 mRNA表达与相应的Sham组相比,均有不同程度的下降(P<0.01),而VEGF mRNA的表达则均有不同程度的增高(P<0.01);在AMI组,随着MI时间的延长,miR-126和VEGF mRNA的表达均逐渐升高,且在AMI 14 d达到高峰（P<0.05）。VEGF 的蛋白表达情况与其基因表达基本一致。结论 大鼠MI后VEGF mRNA及其蛋白的表达明显升高的同时伴随miR-126基因表达的降低,随着缺血时间延长,miR-126 mRNA表达有所恢复。     

急性心肌梗死患者PCI后白介素-6与10的变化及其意义

目的：探讨血白细胞介素-6（IL-6）及IL-10浓度在急性心肌梗死（AMI）患者急诊介入治疗后的变化及其意义。方法：选择60例行急诊经皮冠状动脉介入术（PCI）治疗患者（AMI组）和30例冠状动脉造影正常者（正常对照组）,采用酶联免疫吸附法（ELISA）检测PCI术后第1d及第7d患者的血清IL-6及IL-10的含量,并与正常对照组进行比较分析。结果：与正常对照组相比,AMI组PCI术后患者的血清IL-6[（110.34±26.01）pg/ml比（156.97±68.58）pg/ml]、IL-10[（18.21±4.0）ng/ml比（19.94±10.01）ng/ml]水平及IL-6/IL-10比值[（6.73±2.04）比（10.99±8.24）]明显升高（P〈0.05）,且IL-6与IL-10呈正相关（r=0.44,P〈0.05）;结论：急性心肌梗死后血清白细胞介素-6、白细胞介素-10水平升高,可能参与急性心肌梗死的发生和发展。     

Secretory type II phospholipase A(2) binds to ischemic myocardium during myocardial infarction in humans.

OBJECTIVE: An increase of circulating secretory Phospholipase A(2) (sPLA(2)) is a risk factor for coronary artery disease. We hypothesized that this reflects participation of sPLA(2) in local inflammatory reactions ensuing in ischemic myocardium. Therefore, we studied the course of circulating sPLA(2), in patients with acute myocardial infarction (AMI) or unstable angina pectoris (UAP), and investigated the presence of sPLA(2) in infarcted myocardial tissue. METHODS: Plasma samples of 107 patients with AMI or UAP, collected on admission and at varying intervals thereafter, were tested for the presence of sPLA(2) and C-reactive protein (CRP). Cumulative release values of these parameters were calculated, which allowed for comparison of the results rearranged in time according to the onset of symptoms. By immunohistochemistry we studied the presence of sPLA(2) and CRP in myocardial tissue of 30 patients who died subsequent to AMI. RESULTS: Levels of sPLA(2) became elevated during the disease course in 66 of the 87 patients with AMI, and were higher than those of the patients with UAP of whom 8 of the 20 had elevated levels. By immunohistochemistry sPLA(2) was found to be localized in the infarcted myocardium, particularly in its borderzone, from 12 h after the onset of AMI. Positive staining for sPLA(2) was more extensive than that for CRP. CONCLUSIONS: The localization pattern of sPLA(2) in infarcted myocardium as well as its plasma course, in relation to those of CRP, are in line with a supposed pro-inflammatory role during AMI for sPLA(2) as a generator of lysophospholipids serving as ligands for CRP.     

肝细胞生长因子对犬急性心肌梗死后左心室重构的影响

目的探讨肝细胞生长因子(hepatocyte growth factor,HGF)对急性心肌梗死后左心室重构的影响。方法将12只杂种犬结扎左冠状动脉前降支,复制急性心肌梗死模型,随机分为2组:对照组和治疗组,每组6只。治疗组于梗死心肌周围注射pc-DNA3-HGF基因1 ml,对照组给予等量的生理盐水。分别于术后1、4、8周进行超声心动图检查,检测心功能、左心室重构指标。术后8周取心肌组织行HE染色及天狼猩红染色,图像分析系统测定Ⅰ、Ⅲ型胶原含量。结果术后4周时,治疗组左心室射血分数(LVEF)明显高于对照组(P<0.05)。8周时,LVEF明显升高,左心室舒张末容积较对照组降低(P<0.05)。对照组组内比较显示左心室后壁厚度显著降低(P=0.04)。HE染色可观察到治疗组梗死心肌周围毛细血管较对照组增多,而对照组瘢痕形成明显。天狼猩红染色显示治疗组Ⅲ型胶原含量高于对照组,Ⅰ/Ⅲ型胶原比例低于对照组(P<0.05)。结论HGF可能通过减少胶原的沉积及促进血管增生,减少心肌坏死及瘢痕形成,从而改善心功能及急性心肌梗死后的左心室重构。