重视肝纤维化细胞外基质降解中TIMPs的研究

在正常肝脏纤维组织中存在着细胞外基质(ＥＣＭ)的合成与降解的动态平衡 ,肝纤维化及肝硬化时纤维结缔组织的形成 ,是各种不同致病因子导致ＥＣＭ合成与降解的失衡所致。纤维组织的形成不是一个静止过程 ,而是一个动态过程 ,因此 ,研究肝纤维化及早期肝硬化的可逆性 ,在注意胶原合成过程的同时 ,应加强胶原降解过程的研究。1　胶原降解主要由基质金属蛋白酶 (ＭＭＰｓ)介导既往对肝纤维化ＥＣＭ合成与沉积的研究比较深入。ＥＣＭ主要由胶原以及蛋白多糖、糖蛋白等组成 ,肝星状细胞 (ＨＳＣ)是其主要来源。处于“静止”期的ＨＳＣ主要合成Ⅳ…     

肝纤维化

肝纤维化是各种慢性肝病向肝硬化发展的必经阶段。随着肝脏病变的发展,肝细胞坏死,肝实质弥漫性结节再生,纤维组织包绕、分隔,终致肝脏结构改变,发展为不可逆转的肝硬化。因此,近年对肝纤维化的研究颇受肝脏病学家们重视。 一、肝纤维化的机制 1.肝细胞外基质的改变:正常肝脏的结缔组织,即细胞外基质主要有三种成分:胶原(I、Ⅲ、Ⅳ、Ⅴ型)、非胶原糖蛋白(纤维连接蛋白、层粘蛋白、肝连接蛋白)和多糖(氨基多糖和蛋白多糖)。肝纤维化早期,Ⅲ型胶原纤维增多,发展     

肝纤维化形成中MMPs／TIMPs的动态变化及治疗进展

目前已阐明细胞外基质（ECM）合成与降解失衡,特别是后期降解减少是肝纤维化发生的主要机制。肝脏ECM的代谢主要由基质金属蛋白酶（MMP）及其抑制因子（TIMP）共同调节。MMPs促进ECM降解,而TIMPs通过抑制MMPs阻止ECM降解,从而形成或促进肝纤维化。此外,TIMPs还通过抑制肝纤维化发生、发展过程中具核心作用的肝星状细胞（HSC）凋亡而促进肝纤维化的持续发展。     

TIMPs和MMPs与肝纤维化研究进展

肝纤维化是多种慢性肝损伤的共同后果,进一步则发展为肝硬化,其特征是细胞外基质（ECM）产生和降解不平衡,导致间质胶原及其它基质成分积聚。近年来,与基质降解与沉积有关的基质金属蛋白酶（MMPS）及其基质金属蛋白酶组织抑制因子（TIMPS）在肝纤维化的发生发展过程中得到较深入研究。基质金属蛋白酶是降解ECM最主要的酶类,而基质金属蛋白酶组织抑制因子为MMPS的特异性抑制剂,二者与肝内ECM的沉积与降解密切相关。MMPS及TIMPS与肝纤维化的关系越来越受到人们的重视。研究发现通过调节TIMPS与MMPS基因的表达来治疗肝纤维化将是肝纤维化基因治疗的新途径。     

肥胖与肝纤维化

随着人们生活水平的提高，膳食结构和生活行为方式的改变，肥胖症的发生率正在逐步增高，其不仅为高血压、糖尿病、冠心病、胆石症、痛风、猝死的诱因，而且与肝脏相关疾病如脂肪性肝病、肝纤维化和肝硬化等密切相关。早在1997年，世界卫生组织就将肥胖症列为仅次于吸烟和艾滋病的第三大慢性杀手。肥胖者发生2型糖尿病、心血管病、脂肪肝的危险性分别是普通人群的3倍、2～3倍和7倍。     

肝纤维化非创伤性诊断

肝纤维化是各种慢性肝损伤发展为肝硬化的共同病理过程，对其早期诊断可为药物治疗、预防和预后判断等提供重要的参考。长期以来，肝纤维化的确诊离不开肝活组织检查，这种损伤性检查具有明显不足。因此临床上迫切需要寻找简单且易推广的非创伤性诊断指标诊断肝纤维化。目前仅依靠某种或某几类指标诊断肝纤维化显然是不够全面的，而且这些诊断指标必需经过系列的大样本进行验证以便进一步证实其诊断肝纤维化的准确性。近来在肝纤维化非创伤性诊断方面有不少有价值的临床研究，这些结果对临床医生有很重要的参考价值。     

肝纤维化指标与中医辨证分型的关系

我们检测分析了186例肝炎、肝硬变患者血清4项肝纤维化指标与中医证型的关系。 1 临床资料 186例患者均为1998年3月～1999年11月间,我院门诊和住院病人。男134例,女52例;年龄20～70岁,平均年龄36.2±12.1岁;慢性肝炎者152例,肝炎后肝硬变者34例,病     

肝纤维化标记物的研究进展

肝纤维化是慢性肝病重要的病理特征,也是进一步向肝硬化发展的主要中间环节。早期诊断和防治对阻止肝纤维化发展为肝硬化具有重要意义。肝活检仍是诊断肝纤维化的金标准,但这种创伤性检查具有一定危险性,其本身存在取样误差,也难以重复进行动态观察肝纤维化的程度。为满足临床医疗需要,仍需努力寻求无创伤的诊断方法。研究显示,与肝细胞外间质(ECM)相关的酶和代谢物的检查在对肝纤维化的诊断中具有重要意义,能在某种程度上反映肝内纤维化程度和活动度,本文就近年的研究进展作一阐述。 一、赖氨酰氧化酶(LO)     

肝纤维化诊断与治疗的某些进展

肝病是危害我国劳动人民最严重、最常见的疾病之一,不论是病毒性,还是寄生虫性(主要是血吸虫)肝病的患病率均占全世界之冠.随着分子生物学技术在肝病研究中的应用,业已证明不同的致肝损伤的病因.均可引起肝纤维化.抗肝纤维化已成为治疗各种慢性肝病的中心问题,虽然肝纤维化发生机理尚不清,但肝纤维化的诊断与治疗已有较大的进展.本文扼要介绍这方面的研究进展.     

肝纤维化的血清学诊断

肝纤维化的血清学诊断广州第一军医大学南方医院骆抗先近年来随着肝纤维化研究的逐步深入，肝纤维化的血清学诊断有很大的进展。但其特异性及其在病程中的变化规律，尚未充分阐明，对其诊断意义也还有争议。本文评述现有标志物对临床诊断的应用和限制。（一）肝纤维化标志...     

Expression of TIMP-1 and TIMP-2 in rats with hepatic fibrosis

AIM: To investigate the location and expression of TIMP-1 and TIMP-2 in the liver of normal and experimental hepatic fibrosis in rats. METHODS: The rat models of experimental immunity hepatic fibrosis (n=20) were prepared by the means of immunologic attacking with human serum albumin (HSA),and normal rats (n=10) served as control group. Both immunohistochemistry and in situ hybridization methods were respectively used to detect the TIMP-1 and TIMP-2 mRNA and related antigens in liver. The liver tissue was detected to find out the gene expression of TIMP-1 and TIMP-2 with RT-PCR. RESULTS: The TIMP-1 and TIMP-2 related antigens in livers of experimental group were expressed in myofibroblasts and fibroblasts (TIMP-1: 482±65 vs 60±20; TIMP-2:336±48 vs 50±19, P<0.001). This was the most obvious in portal area and fibrous septum. The positive signals were located in cytoplasm, not in nucleus. Such distribution and location were confirmed bysitu hybridization (TIMP-1/β-actin: 1.86±0.47 vs 0.36±0.08; TIMP-2/β-actin: 1.06±0.22 vs 0.36±0.08,P<0.001). The expression of TIMP-1 and TIMP-2 was seen in the liver of normal rats, but the expression level was very low. However, the expression of TIMP-1 and TIMP-2 in the liver of experimental group was obviously high. CONCLUSION: In the process of hepatic fibrosis, fibroblasts and myofibroblasts are the major cells that express TIMPs.The more serious the hepatic fibrosis is in the injured liver,the higher the level of TIMP-1 and TIMP-2 gene expression.     

TIMP-1表达在实验性大鼠肝纤维化发病中的作用

目的　探讨TIMP 1表达在实验性大鼠肝纤维化发病中的意义及外源性IL 10抗肝纤维化作用的可能机制。方法　 60只SD雄性大鼠随机分为生理盐水对照组 (N组 ,8只 )、CCl4组 (C组 ,2 8只 )和IL 10干预组 (Ⅰ组 ,2 4只 ) ,建立下常对照、CCl4诱导肝纤维化模型及IL 10干预模型。造模第 7周和第 11周 ,采用链霉蛋白酶E、Ⅳ型胶原酶经门静脉原位灌流消化 ,11%Nycodenz密度梯度离心分离肝星状细胞 (HSC)。半定量RT PCR法检测各组HSC的TIMP 1mRNA表达水平 ;免疫细胞化学法检测培养贴壁后HSC的TIMP 1蛋白表达情况。结果　各组均检出TIMP 1的mRNA表达 ;造模第 7周 ,C组与I组的TIMP 1mRNA表达均高于N组 (P <0 .0 1) ,I组低于C组 (P <0 .0 1) ;造模第 11周 ,I组明显低于C组 (P <0 .0 1) ,C组TIMP 1的表达水平较第 7周进一步增加 (P <0 .0 1) ,而I组有所下降 (P <0 .0 5 )。免疫细胞化学法检测各组TIMP 1的蛋白表达变化与mRNA表达变化一致。结论　TIMP 1随着大鼠肝纤维化进展表达逐渐升高 ,IL 10通过抑制TIMP 1的表达 ,起抗纤维化作用     

Methodologic research on TIMP—1,TIMP—2 detection as a new diagnostic index for hepatic fibrosis and its significance

AIM: To set up a new method to detect tissue inhibitors of metalloproteinase-1 and -2(TIMP-1 and TIMP-2) in sera of patients with hepatic cirrhosis, and to investigate the expression and location of TIMP-1 and TIMP-2 in liver tissue of patients with hepatic cirrhosis, and the correlation between TIMPs in liver and those in sera so as to discuss whether TIMPs can be used as a diagnosis index of hepatic fibrosis. METHODS: The monoclonal antibodies (McAbs) of TIMP-1 and TIMP-2 were used to sensitize erythrocytes, and solid-phase absorption to sensitized erythrocytes (SPASE) was used to detect TIMP-1 and TIMP-2 in the sera of patients with hepatic cirrhosis. Meanwhile, with the method of in situ hybridization and immunohistochemistry, we studied the mRNA expression and antigen location of TIMP-1 and TIMP-2 in the livers of 40 hepatic cirrhosis patients with pathologic diagnosis. RESULTS: With SPASE, they were 16.4% higher in the acute hepatitis group, 33.3% higher in the chronic hepatitis group, and the positive rates were 73.6% and 61.2% respectively in sera of hepatic cirrhosis patients, which were remarkably higher than those in chronic hepatitis and acute hepatitis group (P<0.001). In 40 samples of hepatic cirrhosis tissues, all of them showed positive expression of TIMP-1 and TIMP-2 mRNA detected with immunohistochemistry or in situ hybridization (positive rate was 100%). Expression of TIMPs in different degrees could be found in liver tissue with cirrhosis. TIMPs were located in cytoplasm of liver cells of patients with hepatic cirrhosis. There was a significant correlation between serum TIMPs level and liver TIMPs level. CONCLUSION: SPASE is a useful method to detect the TIMP-1 and TIMP-2 in sera of patients with hepatic cirrhosis, and TIMP-1 and TIMP-2 can be considered as a useful diagnostic index of hepatic fibrosis, especially TIMP-1.     

慢性肝病患者血清基质金属蛋白酶-2和基质金属蛋白酶-2组织抑制因子与肝纤维化指标的关系

目的 观察慢性乙型病毒性肝炎（乙肝）和乙肝后肝硬化患者血清中的基质金属蛋白酶-2（MMP-2）、基质金属蛋白酶-2组织抑制因子（TIMP-2）和肝纤维化指标（HA、LN、ⅣC）及其相关性。方法 检测36例慢性乙肝、36例乙肝后肝硬化和20例对照组的血清MMP-2及TIMP-2,同时检测上述肝病患者血清肝纤维化指标。分析MMP-2、TIMP-2和肝纤维化指标之间的相关性。结果 慢性乙肝重度、肝硬化A级、B级、C级患者血清MMP-2、TIMP-2分别较对照组、慢性乙肝轻度、中度明显升高（P〈0．001）;而慢性乙肝轻度、中度患者MMP-2、TIMP-2与对照组比较无显著性差异（P〉0．05）。慢性乙肝轻、中度之间MMP-2、TIMP-2比较无明显差异（P〉0．05）。血清MMP-2、TIMP-2水平分别与HA、LN、ⅣC有良好相关性;MMP-2与后三者的r值分别为0．928、0．909和0．826;TIMP-2与后三者的r值分别为0．688、0．556和0．644,P值均〈0．001。结论 TIMP-2、MMP-2在慢性肝病患者血清中明显升高,并且分别与肝纤维化血清学指标（HA、LN、ⅣC）有良好的相关性。MMP-2和TIMP-2可作为评价纤维化的指标之一。     

MMP-1、TIMP-1及其在肝纤维化中的作用

基质金属蛋白酶(MMP)和金属蛋白酶组织抑制因子(TIMP)是细胞外基质(ECM)合成和降解调节中的两个重要的因素。其中MMP-1主要降解细胞外基质的主要成分Ⅰ、Ⅲ型胶原,TIMP-1可抑制MMP-1的活性。肝纤维化时MMP-1活性下降,而TIMP-1活性不断升高。研究显示,二者活性失衡是导致肝纤维化进展的重要因素。它们的来源结构、活性的调节及功能成为目前的研究热点。     

抑制金属蛋白酶组织抑制因子-2在肝组织中的表达对大鼠肝纤维化发展的影响

我们前期应用反义寡核苷酸技术，以金属蛋白酶组织抑制因子（TIMP）-1基因为靶基因，研究发现抑制TIMP-1的表达可阻止大鼠肝纤维化的发展。肝纤维化时，肝内增生的胶原蛋白主要为Ⅰ、Ⅲ型胶原，Ⅳ型胶原的增生沉积并不占主要地位，但Ⅳ型胶原过度沉积可使肝血窦毛细血管化，肝血流和结构改变，从而加剧肝脏病变。TIMP-2是肝组织内Ⅳ型胶原酶，即基质金属蛋白酶-2（MMP-2）的主要抑制因子，     

血清TIMP-2水平对肝纤维化诊断价值的研究

目的评价HBV感染者血清TIMP-2水平对肝纤维化诊断的临床应用价值。方法采用ELISA法测定498例HBV感染者和100例正常对照者血清TIMP-2,采用放射免疫分析法检测HA、PCⅢ、CⅣ和LN,和采用全自动酶法测定丙氨酸氨基转移酶（ALT）。结果与健康正常人比,HBV感染者五项指标均有不同程度的升高,除慢性HBV携带者PCⅢ、CⅣ、LN、ALT和慢性肝炎轻度患者CⅣ水平与对照组比无统计学差异外,其余各组均与对照组比有显著性差异（P〈0.05）;从急性肝炎至肝硬化患者血清TIMP-2水平依次进行性升高,其中慢性HBV携带者与急性肝炎患者血清TIMP-2水平分别为78.56±26.23ng/ml和92.65±21.93ng/ml,两者相比差异显著（P〈0.01）。血清TIMP-2与HA、PCⅢ、CⅣ和LN呈显著正相关（P〈0.05）,与ALT也呈正相关（P〈0.05）。结论本文检测的肝纤维化指标均可不同程度地反映肝脏的纤维化程度,其中以血清TIMP-2较为可靠和有效。     

双甲五灵胶囊与肝纤维化血清TIMP-1的变化及临床疗效观察

目的观察自行研制的中药双甲五灵胶囊治疗慢性肝炎患者前后血清基质金属蛋白酶组织抑制剂1(TIMP1)的变化及意义,并观察双甲五灵胶囊治疗的临床疗效。方法将226例慢性肝炎患者随机分为双甲五灵胶囊治疗组和对照组,观察两组治疗半年前后临床症状、体征、肝功能、血清透明质酸(HA)、Ⅲ型前胶原(PCⅢ)、Ⅳ型胶原(CⅣ)、层粘连蛋白(LN)以及TIMP1的变化,并进行统计学处理。结果双甲五灵胶囊治疗组与对照组比较,治疗组患者临床症状、体征、肝功能及血清肝纤维化指标明显好转(P<0.01)。结论双甲五灵胶囊可使患者血清中TIMP1水平明显降低,用于防治肝纤维化有效。双甲五灵胶囊对防治慢性肝炎肝纤维化有一定效果。     

Alpha-2-macroglobulin and hepatic fibrosis

Alpha-2-macroglobulin (A₂M) is a proteinase inhibitor. Cells synthesizing A₂M are in first-order hepatocytes and in second-order activated Ito cells (in culture starting at day 4–5 after seeding). This study was undertaken in 525 alcoholic patients with different histological stages of alcoholic liver disease to assess if the A₂M could improve the diagnostic value of PGA index for detection of cirrhosis or fibrosis among drinkers, particularly in patients without clinical symptoms of liver failure and portal hypertension, and to assess the specific correlation of serum A₂M with the score of liver fibrosis adjusted for steatosis and alcoholic hepatitis and thereafter adjusted for GGT, PT, and ApoA1, the three components of the PGA index. In 525 alcoholic patients, we have demonstrated the independent diagnostic value of A₂M. The predictive values of the weighted score, using linear discriminant function combining PT, GGT, ApoA1 and A₂M of the PGAA score and of the PGA score were assessed in a training step and validated in a second step. Then, 316 alcoholic clinically asymptomatic patients were studied. In these patients, the discriminant function permitted correct classification of 72% of patients. The PGAA index had comparable diagnostic value with 70% of patients correctly classified. On the other hand, the PGA index including only PT, GGT, and ApoA1 had classified correctly less patients (65%) than the discriminant function and the PGAA index (P<0.01). For a value of 7, PGAA had 79% specificity and 89% sensitivity for the diagnosis of cirrhosis. A₂M was positively correlated with the grade of fibrosis (r=0.39P<0.01). The correlation persisted whatever the degree of steatosis and the degree of alcoholic hepatitis and after adjustment for GGT, PT, and ApoA1. When liver biopsy is not possible, PGAA could be useful for the diagnosis of asymptomatic cirrhosis among drinkers.