苯妥英钠促进心肌梗死后大鼠心室基质金属蛋白酶活性及胶原沉积

目的 研究苯妥英钠对急性心肌梗死(AMI)后大鼠心室基质金属蛋白酶(MMPs)活性和胶原合成的影响及其促进心肌梗死后组织修复的机制.方法 用Wistar大鼠建立AMI模型,将大鼠分成苯妥英钠组、对照组和假手术组,在造模后处死动物,取心室,一部分用组织学方法分析;另一部分采用Gelatin Zymography测定MMPs活性.结果 苯妥英钠组14 d时梗死区厚度大于对照组,非梗死区心肌横断面积小于对照组;AMI后梗死区胶原容积分数苯妥英钠组高于对照组;AMI后苯妥英钠组Ⅰ/Ⅲ型胶原高于对照组(P＜0.05);心室梗死区MMPs活性相对于假手术组明显上调(P＜0.05).结论 苯妥英钠可促进AMI后早期梗死区胶原的合成,MMP-2和MMP-9可能参与了此机制.     

心室重构及心衰时基质金属蛋白酶的活性变化

心室重构引起心肌纤维化和进行性心室扩张 ,最终导致心力衰竭。在心肌中存在能降解有所心脏基质成分的基质金属蛋白酶 (MMPs) ,是重构过程中引起心脏基质降解和心肌纤维化的主要因素。在心室重构和心力衰时MMPs的活性升高 ,使纤维胶原降解、细胞外基质重构和进行性心室扩张。研究MMPs的活性变化对限制心室重构和延缓心衰进展的治疗方面具有指导意义     

糖尿病足患者血清基质金属蛋白酶水平变化

目的:分析糖尿病足患者血清基质金属蛋白酶2(MMP-2)、MMP-9总水平和活性水平变化及临床意义。方法:在本院住院的糖尿病足病患者80例作为糖尿病足组(DF组),同期住院无足病糖尿病患者80例为非糖尿病足组(NDF组),年龄、性别匹配的健康人80例作为对照组(CON组)。ELISA法测定各组血清MMP-2和MMP-9总水平,明胶酶谱法检测各组血清MMP-2、MMP-9活性水平。多因素回归分析影响MMP的危险因素。结果:CON、NDF和DF各组血清MMP-2、MMP-9总水平依次升高(P均<0.05)。DF组和NDF组MMP-2活性高于CON组(P均<0.05),DF组和NDF组水平差异无统计学意义(P>0.05);DF组MMP-9活性水平高于CON组和NDF组(P均<0.05)。多元回归分析显示,DF、糖化血红蛋白(HbA1c)、病程和年龄是MMP-9活性升高的危险因素。结论:糖尿病患者血清MMP-2和MMP-9总水平和活性升高,是DF发生和发展的重要因素。     

基质金属蛋白酶与胎膜早破

胎膜早破（preterm premature of the fetal membranes，PROM）和足月前胎膜早破（P—PROM）是威胁母婴健康的常见并发症。PROM的发生率是10％；P—PROM的发生率是2％-3.5％，30％-40％的早产与此有关，而85％的新生儿发病率和死亡率由早产引起。胎膜破裂后，由于屏障作用消失，将可能引起羊膜腔感染、围产期感染、败血症、新生儿窒息等严重的并发症，如果处理不当可危及母儿安全与健康，因此PROM一直受到产科界的关注。     

耐力运动大鼠跟腱胶原、基质金属蛋白酶1及其抑制剂1的表达

背景：胶原是肌腱细胞外基质中的主要成分,基质金属蛋白酶是降解肌腱细胞外基质蛋白的重要蛋白酶。 目的：观察12周跑台运动对大鼠跟腱胶原、胶原Ⅰ、基质金属蛋白酶1及其抑制剂1表达的影响。 方法：将20只雄性SD大鼠随机分为对照组和运动组。第1周每天运动20 min,速度由12 m/min递增至20 m/min;以后跑台速度均为20 m/min,第2周坡度为5%,时间为30 min,第3~12周坡度为10%,时间为40 min,共运动12周。对照组正常饲养。 结果与结论：末次运动后24 h取大鼠跟腱。与对照组比较,运动组大鼠跟腱前胶原Ⅰα1、基质金属蛋白酶1及其抑制剂1 mRNA的表达明显升高(P < 0.05或P < 0.01),羟脯氨酸的含量也有所增多,但与对照组比较差异无显著性意义(P > 0.05)。表明长期耐力运动可以提高跟腱中胶原的合成和降解能力。     

血管紧张素Ⅱ对肥厚心肌基质金属蛋白酶及细胞外基质的影响

目的: 探讨血管紧张素Ⅱ(AngⅡ)受体（AT₁,AT₂）拮抗剂对梗死心脏肥厚心肌组织基质金属蛋白酶(MMPs)及细胞外基质成份的影响。方法: 结扎大鼠左冠状动脉建立心肌梗死模型，术前7 d起分别用安慰剂、AT₁受体拮抗剂撷沙坦（valsartan）（10 mg·kg^-1·d^-1）、AT₂受体拮抗剂PD123319（30 mg·kg^-1·d^-1）。术后1、3、7、14 d分别检测室间隔（IS）MMP-2,3,9及其抑制物-1（TIMP-1）蛋白表达，以及细胞基质纤连蛋白（FN）、肌腱蛋白（TN-C）表达，免疫荧光分析FN、TN-C分布。结果: 心肌梗死14 d, IS呈典型的肥厚心肌病变。 手术组大鼠室间隔MMP-2、3、9及TN-C蛋白表达显著高于假手术组（P<0.01），TIMP-1和FN蛋白表达显著降低（P<0.01）; 手术加valsartan组 MMP-2、3、9 和 TN-C 蛋白表达明显低于手术组及手术加PD123319组, 相反， TIMP-1 和FN 蛋白表达显著高于手术组及手术加PD123319组 (P<0.01); 手术组与手术加PD123319组间MMP-2、3、9、TIMP-1、FN、TN-C蛋白表达差异无显著（P>0.05）。结论: AngⅡ参与心肌梗死心肌组织的重塑，通过AT1起作用调节MMPs降解细胞外基质， AT₁受体拮抗剂的心脏保护作用与其抑制MMPs有关。     

大肠癌组织中基质金属蛋白酶-2和基质金属蛋白酶-9的表达

目的：探讨大肠癌组织中基质金属蛋白酶－2（MMP－2）和基质金属蛋白酶－9（MMP－9）的表达与临床病理参数之间的关系。方法：应用免疫组织化学S－P法检测87例大肠癌组织中MMP－2和MMP－9的表达情况。结果：87例大肠癌组织中MMP－2和MMP－9的表达阳性率分别为56．3％和55．2％。MMP－2和MMP－9在侵及肌层的阳性表达率明显低于侵及浆膜层，淋巴结转移阳性组高于淋巴结转移阴性组，差异均有显著性（P＜0．05）。Dukes分期中，C、D期中MMP－2和MMP－9的阳性表达率明显高于A、B期（P＜0．05），而与性别、年龄、肿瘤部位、组织学类型和分化程度均无关（P＞0．05）。结论：MMP－2和MMP－9可能在大肠癌浸润转移过程中发挥重要作用。     

基质金属蛋白酶与肺纤维化

基质金属蛋白酶（MMPS）是一类结构类似、生物学作用相近、金属离子依赖的蛋白酶的总称,是机体内细胞外基质（ECM）降解的主要酶系。MMPS及其组织特异性抑制剂（TIMPS）之间的失衡、MMPS与ECM之间的失衡可能是导致肺组织损伤、重塑和纤维化的重要机制之一。本文试就MMPS与肺纤维化的关系作一简要的综述。     

p38 MAPK及基质金属蛋白酶在心力衰竭病人心肌重构中的意义

目的: 探讨不同程度心力衰竭病人心肌组织丝裂素活化蛋白激酶（p38 MAPK）、基质金属蛋白酶家族（MMP-2、3、9）、细胞外基质（ECM）纤连蛋白（FN）表达与心肌重构的关系。方法: 选择因二尖瓣关闭不全心脏病接受二尖瓣置换术的心力衰竭病人39例，正常对照8例来自意外伤亡的器官捐献者。光镜检查心肌组织病理变化;免疫沉淀法检测心肌组织p38 MAPK磷酸化，及p38 MAPK、MMP-2、3、9蛋白表达; 免疫荧光法检查心肌组织FN的分布。结果: 瓣膜病所致心力衰竭病人心肌组织呈典型的心肌重构病理改变。心力衰竭组心肌 p38 MAPK 磷酸化明显强于对照组（P<0.05），随心功能恶化，其表达逐渐增加（P<0.05或P<0.01）。 心力衰竭组心肌组织MMP-2、3、9蛋白表达明显强于正常对照组，各心力衰竭组与正常对照组相比差异显著（P<0.05或P<0.01）; 相反，心力衰竭组心肌组织FN蛋白表达明显弱于正常组，各心力衰竭组与正常对照组相比差异显著（P<0.05或P<0.01）。结论: 心力衰竭病人通过激活p38 MAPK诱导心肌细胞肥大、坏死，通过MMP-2、3、9表达量的增高降解心肌细胞外基质FN，共同参与心肌重构的病理过程而恶化心功能。     

基质细胞衍生因子1对骨关节炎软骨Ⅱ型胶原及分泌基质金属蛋白酶的影响*

背景：基质细胞衍生因子1/趋化因子受体4信号通路在骨关节炎的发病中起关键作用。 目的：观察外源性基质细胞衍生因子1对骨关节炎软骨Ⅱ型胶原及分泌基质金属蛋白酶的影响。 方法：分别取因骨关节炎行膝关节置换患者软骨组织块40块,作为实验组;取因创伤性截肢患者膝关节的正常软骨块40块,作为对照组;置入DMEM培养液中,加入79,392 μg/L外源性基质细胞衍生因子1,分别培养48 h和96 h。 结果与结论：实验组与对照组培养48,96 h后,各时间段Ⅱ型胶原免疫组织化学染色皆呈阳性,但高浓度基质细胞衍生因子1培养液条件下时间越长Ⅱ型胶原降解越严重;实验组与对照组同一时间段同浓度基质细胞衍生因子1培养液条件下基质细胞衍生因子1水平无明显差异(P > 0.05);高浓度基质细胞衍生因子1培养液条件下同一时间段实验组比对照组中促使软骨释放基质金属蛋白酶多(P < 0.05)。提示基质细胞衍生因子1可通过基质细胞衍生因子1/趋化因子受体4信号通路调节骨关节炎软骨基质金属蛋白酶表达并致软骨Ⅱ型胶原降解。     

Semiquantitative analysis of collagen types in the hypertrophied left ventricle

Cardiac fibrosis is a characteristic feature of left ventricular hypertrophy. The aim of this study was to develop a simple and accurate method to analyse collagen accumulation, taking into account the variation in cardiac muscle fibre orientation and nonuniform collagen distribution. This technique was used to determine the amount and types of collagen that accumulate during pressure overload cardiac hypertrophy. These data were correlated with myocyte size, and with the diastolic stress–strain relationship of the intact myocardium. Myocyte size was significantly increased in the hypertrophied hearts, compared with age and sex matched controls (control 363±25 μm² vs experimental 244μm²; mean± S.E. , P < 0.05). No overall collagen accumulation was observed in the hypertrophied hearts, but a significant increase in collagen I was found with a reduction in the amount of collagen III in experimental animals. Since no increase in diastolic stiffness of the hearts was observed, these results indicate that an increase in the overall collagen content of the heart, rather than the upregulation of a specific type, may be necessary to cause diastolic dysfunction.     

ET-NO系统与心肌胶原代谢的关系

目的：探讨心肌缺血缺氧状态下局部内皮素（ＥＴ）和一氧化氮（ＮＯ）与心肌胶原代谢的关系。方法：应用异丙肾上腺素（ＩＳＰ）注射大鼠，造成心肌缺血缺氧和心肌坏死模型。检测血清内ＧＯＴ、ＣＫ、ＬＤＨ、ＥＴ含量，并检测心肌组织匀浆内ＥＴ、ＮＯ含量变化和胶原蛋白含量以及细胞外间质（ＥＣＭ）的增殖情况。结果：注射ＩＳＰ后，血清ＧＯＴ、ＣＫ、ＬＤＨ活性增加，与此同时，心肌匀浆内ＥＴ含量上升和ＮＯ含量下降，ＥＣＭ效应细胞增殖和心肌胶原含量升高。结论：心肌缺血缺氧后，心肌局部合成释放ＥＴ增加，ＮＯ合成减少，胶原蛋白含量增加，说明ＥＴ等生物因子与心肌间质胶原代谢变化相关     

无细胞胶原基质的研究进展

天然胶原类组织,经过脱细胞处理后,降低免疫原性,可作为组织工程的支架材料,本文就脱细胞的方法以及无细胞胶原基质的研究进展作一综述。     

别嘌呤醇降低大鼠心肌非梗死区胶原重塑

目的探讨黄嘌呤氧化酶抑制剂别嘌呤醇对大鼠非梗死区心肌胶原重塑的影响。方法结扎冠脉前降支制作大鼠心肌梗死模型,随机分为假手术组,心肌梗死组和别嘌呤醇组,每组分别于7、14、21和28d时测定心肌组织胶原含量,Ⅰ、Ⅲ型胶原容积分数(CVF)、mRNA的改变及Ⅰ/Ⅲ型胶原比值,黄嘌呤氧化酶(XO)和清除活性氧活力。28d时另检测XO蛋白表达及左心室病理改变。结果心肌梗死组心肌胶原含量,Ⅰ、Ⅲ型CVF及mRNA升高,Ⅰ/Ⅲ型胶原比值先下降后升高,XO活力增加,清除活性氧活力降低(P<0.05或P<0.01)。别嘌呤醇组明显缓解了上述指标的变化。结论别嘌呤醇能够降低非梗死区胶原沉积和Ⅰ/Ⅲ型胶原比值,改善心肌梗死后心肌胶原重塑。     

The enamel protein ODAM promotes mineralization in a collagen matrix

ABSTRACT

Purpose/aim of the study: Odontogenic ameloblast-associated protein (ODAM) is predominantly expressed during the maturation stage of enamel formation and interacts strongly with amelotin (AMTN). AMTN is involved in enamel mineralization, but the effect of ODAM on mineralization has not been investigated. This study determined whether ODAM was able to induce hydroxyapatite (HA) mineralization in modified simulated body fluid (SBF) and in a collagen matrix in vitro. Materials and methods: To monitor the kinetics of calcium phosphate mineralization, recombinant human (rh) ODAM protein in SBF buffer was incubated at 37°C and a light-scattering assay was conducted at intervals. To investigate the nucleation of ODAM in collagen matrix, the ODAM-impregnated collagen hydrogel was incubated in SBF buffer for 24 hours. Bovine serum albumin (BSA) was used as negative control. Mineral deposits were visualized using electron microscopy. Results: The presence of rh-ODAM protein in SBF resulted in higher light-scattering values after 18–24 hours. Calcium phosphate precipitates were observed on the surface of the ODAM-treated, but not BSA-treated collagen hydrogel after 24 hours in SBF. TEM and SAED analyses showed that these crystals consisted of needle-like HA. Conclusion: Similar to AMTN, ODAM is able to promote HA nucleation in a dose-dependent manner in SBF, and even outside of its biological context in vitro.     

Fibrillolysis and electrophoretic determination of actin and myosin in hypertrophied human myocardium

Summary Destructive myofibrillar lesions, particularly degenerative fibrillolysis in hypertrophied hearts, were studied with the electron microscope in left ventricular myocardium samples obtained from autopsies with post mortem periods not exceeding 195 min. The contractile protein composition of these samples was determined electrophoretically. 18 cases were studied, grouped as follows: Group I, composed of 5 cases showing normal hearts which were employed in the determination of normal electrophoretic values. Group II: 10 cases with hypertrophic hearts, 1 of them showing contraction bands and decreased myosin, 6 others with fibrillolytic lesions of which 3 presented a decrease in myosin and 3 possesed normal myosin values. None of the cases showed a decrease in actin values. Group III was composed of 3 cases of hearts with normal weights that showed ultrastructural alterations of the myofibrils: 1 with myofibrillar disarray and normal electrophoretic values, 1 with incomplete contraction bands and normal protein values and 1 with focal myofibrillar disgregation and myosin decrease.It is concluded that in some cases of degenerative fibrillolytic lessions a decrease of myosin occurs. The method employed does not rule out that apparently normal actin and myosin values might be due to the pressence of contractile proteins in a denatured state that does not affect their electrophoretic mobility.Supported by Dirección de Investigaciones, grant No 65/78, Catholic University of ChileFormerly Fellow of the Alexander von Humboldt Foundation     

Extracellular matrix profiles in the progression to heart failure. European Young Physiologists Symposium Keynote Lecture-Bratislava 2007

The myocardial extracellular matrix (ECM), which preserves the geometry and integrity of the myocardium, is a dynamic structure whose component proteins are maintained by a finely controlled homeostatic balance between deposition and degradation. One of the key targets in cardiology is the elucidation of the molecular mechanisms which mediate pathological remodelling of this matrix causing the transition from compensatory hypertrophy to congestive decompensated heart failure. In response to injury or increased workload, cardiac remodelling including myocyte hypertrophy, develops as the heart attempts to compensate for increased wall stresses. Persistence of these stresses over extended time periods leads to disruption of ECM homeostasis resulting in irreversible maladaptive cardiac remodelling, ventricular dilatation and finally heart failure. ECM remodelling is regulated by the matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs). Clinical studies and experimental models of cardiac disease states have reported alterations in the balance between the MMPs and TIMPs in the failing heart and crucially at intermediate time points in the progression to failure. This article reviews the recent clinical, genetic and experimental approaches employed to compare ECM, MMP and TIMP profiles in healthy, compensated and failing hearts and identifies common themes in the perturbation of ECM homeostasis in the transition to heart failure.