肝星状细胞与肝纤维化

1　肝纤维化的基本概念(1)肝纤维化是指各种原因所致的肝脏内纤维结缔组织增生,其特征为大量细胞外基质在Ｄｉｓｓｅ间隙沉积。(2)肝纤维化时不仅细胞外基质含量增加,而且细胞外基质的组成成分也发生了改变,正常肝脏Ｄｉｓｓｅ间隙细胞外基质是构成基底膜的成分,而肝纤维化时细胞外基质为形成纤维的胶原和纤维连接蛋白〔1〕。(3)在各种原因引起的肝纤维化中,肝脏细胞外基质含量均增加,但原因不同的肝纤维化早期,其肝脏增加的细胞外基质分布是不同的,如病毒性肝炎引起的肝纤维化主要分布在门脉区,而酒精引起的肝纤维化主要分布在中央静脉周围…     

肝星状细胞凋亡与肝纤维化

近十年来对肝纤维化形成的机理研究取得了令人鼓舞的进展。越来越多的临床及实验证据表明,肝纤维化是可以逆转的［１］,这一观点逐渐被广泛接受。肝星状细胞（ｈｏｐａｔｉｃｓｔｅｌｌａｔｅｃｅｌｌ,ＨＳＣ）的激活是肝纤维化形成的中心环节［２］,ＨＳＣ在肝纤维化逆转过程中的作用也成为研究热点之一。Ｂｕｒｔ［３］认为,肝纤维化逆转时ＨＳＣ的减少是由于激活状态的ＨＳＣ转化为静止状态。但最新的研究表明,肝纤维化恢复期,激活状态的ＨＳＣ减少主要通过凋亡机制,而不是表型的转化［４］。几位学者分别对ＨＳＣ凋亡的机制进行…     

肝星形细胞表达CYPⅡB2与肝纤维化关系的实验研究

目的探索CYPⅡB2在正常与肝纤维化大鼠肝组织中的表达,评价螺内脂的治疗作用。方法取雄性Wistar大鼠160只,随机分为4组,每组40只。模型组CCl4油0.25ml／100mg皮下注射,每周3次;螺内脂组CCl4油注射的同时予以螺内脂20mg·kg·d-1灌胃,1次/d;马洛替酯组CCl4油注射的同时予以马洛替酯50mg·kg-1·d-1灌胃,1次/d;对照组橄榄油皮下注射。光镜及电镜下动态观察组织学改变,图像分析仪测量胶原面积。RT-PCR和原位杂交检测CYPⅡB2的表达。结果原位杂交及RT-PCR显示CYPⅡB2表达定位于星形细胞胞浆,在纤维化形成时表达增强。第4、6周,螺内脂组肝纤维化分级、胶原面积低于模型组(P<0．05)。第8、10周,螺内脂组与模型组相比差异无显著性(P>0.05)。结论CYPⅡB2在纤维化肝脏的星形细胞中表达增强。螺内脂对早中期肝纤维化具有一定的治疗作用。     

肝星状细胞与肝纤维化

肝纤维化是各种慢性肝病损伤修复过程的共同结果,由于肝内纤维生成和降解失衡,导致过多的胶原在肝内沉积,常伴有炎症、缺血缺氧,最终可发展为肝硬化。目前认为,细胞外基质（ECM）过多产生和沉积是肝纤维化的核心表现,活化的肝星状细胞（HSC）仍是细胞外基质的主要细胞来源。因此,肝星状细胞的活化是肝纤维化发生的中心环节。     

肝星状细胞与肝纤维化

近年来已获公认,肝星状细胞是肝纤维化时细胞外基质（ ｅｘｔｒａｃｅｌｌｕｌａｒ ｍａｔｒｉｘ, ＥＣＭ）过多产生和沉积的主要细胞来源。 １８７６年德国 ｖｏｎ Ｋｕｐｆｆｅｒ首次描述星状细胞（ Ｓｔｅｒｎｚｅｌｌｅｎ）,后来的文献中又称之为 Ｉｔｏ细胞、脂细胞、贮脂细胞、窦周细胞等等。１９９６年Ｈｅｐａｔｏｌｏｇｙ发表了９８位著名国际肝病学家的建议,认为仍以肝星状细胞（ｈｅｐａｔｉｃ ｓｔｅｌｌａｔｅ ｃｅｌｌ, ＨＳＣ）命名为宜,此建议已日益被采纳应用。近年关于星状细胞的研究日多,本文只涉及几个问题：细…     

肝星状细胞的活化与肝纤维化

肝纤维化是机体对损伤的一种修复作用，即使可以应用基因或其他疗法彻底消除纤维化，但机体对抑制或消除纤维化后将产生何种反应及后果尚难预测。肝星状细胞（hepatic stellate cells，HSC）是引起肝纤维化的主要细胞，对HSC与其活化型一肌成纤维细胞（myofibroblast，MF）在肝损伤中作用的研究已颇为深入，而HSC激活在肝纤维化发生、发展中的作用甚为重要。     

肝星状细胞在肝纤维化中的作用

肝纤维化是肝硬化的早期阶段,其发生涉及肝内多种细胞,而肝星状细胞在肝纤维化的发生发展中具有重要作用,本文综合国内外最新研究,对肝星状细胞的形态及其在肝纤维化中的作用(活化、信号转导、凋亡等)进行了综述。     

肝星状细胞凋亡与肝纤维化

肝纤维化病理过程中HSC的凋亡机制近来年为人们所认识,并进行了相关的研究,笔者就这一方面的文献作一综述.     

四氯化碳诱导的大鼠肝纤维化肝组织中SHP2表达与在体肝星状细胞活化及增殖的关系

目的 探讨四氯化碳诱导的大鼠肝纤维化肝组织及在体肝星状细胞(HSC)的含SH2结构域的蛋白酪氨酸磷酸酶2(SHP2)表达变化与在体HSC活化及增殖的关系。方法 随机将50只健康雄性SD大鼠分为对照组(10只)、模型组(40只),采用腹腔注射四氯化碳法构建大鼠肝纤维化模型，Masson三色及HE染色检测大鼠肝组织的病理组织学变化，免疫组织化学染色检测大鼠肝组织的α-平滑肌肌动蛋白(α-SMA)及SHP2表达，SHP2与α-SMA免疫荧光双标记检测大鼠肝组织中活化HSC的SHP2表达。结果 与对照组大鼠肝组织的α-SMA阳性表达积分光密度值(IOD)(0.09±0.01)相比，造模不同时间(2周、4周、6周、8周)大鼠纤维化肝组织的α-SMA阳性表达IOD (0.13±0.01、0.18±0.01、0.24±0.02、0.28±0.02)显著增加(P<0.05),并随着造模时间延长逐渐升高(P<0.05),即在体HSC的活化及增殖逐渐加快(α-SMA是HSC的活化标志)。造模不同时间(2周、4周、6周、8周)大鼠纤维化肝组织的SHP2阳性表达IOD (0.23±0.01、0.2...     

肝星状细胞与肝纤维化

肝纤维化是各种慢性肝病共有的病理改变,逆转肝纤维化可阻止大多数慢性肝病进展。肝星状细胞(HSC)是肝内一种具有多功能、变化不定的非实质细胞,HSC活化是肝纤维化发生的中心环节。阐明其关系,有助于以HSC为靶点的肝纤维化方面的研究。     

肝硬化时肝窦毛细血管化形成机制

目的:探讨肠源性内毒素血症在肝窦毛细血管化形成中的作用及其可能机制.方法:♂ Wistar大鼠40只,完全随机分为模型组(n=32)与正常对照组(n=8),采用复合因素致肝硬化大鼠模型.模型组分别在饲养第2,4,6,8周末,正常对照组在实验开始时,经肠系膜上静脉末端穿刺测PVP.肝脏HE、VG染色,肝脏免疫组织化学染色观察α-SMA、LN、TGF-β1的动态表达,测定外周血中的内毒素、TNF-α、ALT的动态变化,采用扫描电镜观察肝窦内皮细胞失窗孔情况.结果:模型组ALT在第2周末达到高峰(57.84±7.57IU/L),随后逐渐下降;内毒素在第2、4、6周末,各点呈递增趋势,到第8周末时略有下降;TNF-α在第2、4周末呈递增趋势,到第6周末时略有下降,第8周末时又逐渐升高,但各点组均较对照组明显升高(均P<0.05);模型组PVP在第2、4周末,各点呈递增趋势,到第6周末时略有下降,第8周末时又逐渐升高;肝窦内皮细胞扫描电镜结果示随着肝纤维化及硬化程度的加重,窗孔逐渐变小、变少至消失;LN、TGF-β1免疫组织化学染色结果示随着病变的发展,与对照组和同指标前一时间组相比阳性表达逐渐增强(均P<0.05).α-SMA免疫组织化学染色在第2、4、6周末,阳性表达逐渐增强,到第8周末时略有下降.结论:肝硬化大鼠发生了肠源性内毒素血症,其可使TGF-β1、TNF-α、LN等合成增多,促进肝窦内皮细胞去窗孔化,间接参与肝窦毛细血管化的形成.     

Hemodynamic changes in hepatic sinusoids of hepatic steatosis mice

BACKGROUND Fatty liver(FL) is now a worldwide disease. For decades, researchers have been kept trying to elucidate the mechanism of FL at the molecular level, but rarely involve the study of morphology and medical physics. Traditionally, it was believed that hemodynamic changes occur only when fibrosis occurs, but it has been proved that these changes already show in steatosis stage, which may help to reveal the pathogenesis and its progress. Because the pseudolobules are not formed during the steatosis stage, this phenomenon may be caused by the compression of the liver microcirculation and changes in the hemodynamics.AIM To understand the pathogenesis of hepatic steatosis and to study the hemodynamic changes associated with hepatic steatosis.METHODS Eight-week-old male C57 BL/6 mice were divided into three groups randomly(control group, 2-wk group, and 4-wk group), with 16 mice per group. A hepatic steatosis model was established by subcutaneous injection of carbon tetrachloride in mice. After establishing the model, liver tissue from mice was stained with hematoxylin and eosin(HE), and oil red O stains. Blood was collected from the angular vein, and hemorheological parameters were estimated. A two-photon fluorescence microscope was used to examine the flow properties of red blood cells in the hepatic sinusoids.RESULTS Oil red O staining indicated lipid accumulation in the liver after CCl_4 treatment.HE staining indicated narrowing of the hepatic sinusoidal vessels. No significant difference was observed between the 2-wk and 4-wk groups of mice onmorphological examination. Hemorheological tests included whole blood viscosity(mPas, γ = 10 s-1/γ = 100 s-1)(8.83 ± 2.22/4.69 ± 1.16, 7.73 ± 2.46/4.22 ±1.32, and 8.06 ± 2.88/4.22 ± 1.50), red blood cell volume(%)(51.00 ± 4.00, 42.00 ±5.00, and 40.00 ± 3.00), the content of plasma fibrinase(g/L)(3.80 ± 0.50, 2.90 ±0.80, and 2.30 ± 0.70), erythrocyte deformation index(%)(44.49 ± 5.81, 48.00 ±15.29, and 44.36 ± 15.01), erythrocyte electrophoresis rate(mm/s per V/m)(0.55 ±0.11, 0.50 ± 0.11, and 0.60 ± 0.20), revealing pathological changes in plasma components and red blood cells of hepatic steatosis. Assessment of blood flow velocity in the hepatic sinusoids with a laser Doppler flowmeter(mL/min per100 g)(94.43 ± 14.64, 80.00 ± 12.12, and 67.26 ± 5.92) and two-photon laser scanning microscope(μm/s)(325.68 ± 112.66, 213.53 ± 65.33, and 173.26 ± 44.02)revealed that as the modeling time increased, the blood flow velocity in the hepatic sinusoids decreased gradually, and the diameter of the hepatic sinusoids became smaller(μm)(10.28 ± 1.40, 6.84 ± 0.93, and 5.82 ± 0.79).CONCLUSION The inner diameter of the hepatic sinusoids decreases along with the decrease in the blood flow velocity within the sinusoids and the changes in the systemic hemorheology.     

Anatomo-pathologic study of hepatic toxicity in intra-arterial hepatic chemotherapy

Intra-arterial hepatic chemotherapy is effective in the treatment of colorectal or endocrine carcinomas liver metastasis. However it is potentially toxic for the healthy liver. To check this, we studied non tumoral liver specimens in 14 patients treated by intra-arterial chemotherapy with 5 fluorouracil, 5 fluoro-2 deoxyuridine and an association of 5 fluorouracil and streptozotocin. The main hepatic lesions observed were: sclerosing cholangitis, central vein (dilatation and fibrosis) and moderate hepatocellular necrosis or cholestasis in the centrolobular area. Thus intra-arterial hepatic chemotherapy has important toxic effects on healthy liver, even if clinical and biological liver disturbances are minimal in most cases. Caution must be exercised in using this method.     

Progressive hepatic decompensation with terminal hepatic coma in sarcoidosis

Digestive Diseases and Sciences - In a case of sarcoidosis with portal hypertension, progressive hepatic decompensation terminated in hepatic coma. The difficulties encountered in the diagnosis of...     

Inhibitors of hepatic DNA synthesis in fulminant hepatic failure

In certain etiological groups of patients with fulminant hepatic failure, poor survival may be due to lack of liver regeneration.In vitro experiments have shown that fulminant hepatic failure serum is cytotoxic to rabbit hepatocytes and inhibits DNA synthesis on short-term incubation with isolated regenerating rat hepatocytes. When fulminant hepatic failure serum is injected into partially hepatectomized rats at the time of maximal DNA synthesis, [³H]thymidine incorporation into hepatic DNA is reduced significantly. The effect is greater with sera obtained from patients with fulminant hepatic failure due to non-A, non-B hepatitis or an adverse drug reaction and is associated with a<10,000-dalton fraction. No stimulation of DNA synthesis is observed with injection of the >10,000-dalton serum fraction into normal rats. In preliminary experiments, no increase in epidermal growth factor production has been found in liver failure. Overall, the substances present in fulminant hepatic failure serum appear to be inhibitory rather than stimulatory for liver cell regeneration.Presented at the Proceedings of the International Meeting on Normal and Neoplastic Growth in Hepatology, Bari, Italy, June 1989.     

Prognostic value of hepatic volumetry in fulminant hepatic failure

Serial hepatic volumetry calculated from the liver area on abdominal computed tomography was performed in 19 patients with fulminant hepatic failure to determine a relationship between liver volume and prognosis. All patients received intensified artificial liver support comprised of plasma exchange and hemodiafiltration using high-performance membranes, and 10 patients survived. Liver volume was significantly larger in survivors than in nonsurvivors, both in an initial volumetry performed at the onset of coma and in subsequent volumetry performed 10–20 days after the onset of coma. The difference became more significant in the subsequent volumetry because of the recovery of liver size in some of the survivors and progressive liver shrinkage in all nonsurvivors. All patients with a liver volume greater than 656 ml at 10–20 days after the onset of coma survived, whereas all but one patient with a liver volume less than that died. Multivariate analysis revealed only liver volume in subsequent volumetry had discriminatory power upon prognosis among six prognostic factors. These observations imply that in order to obtain an accurate prediction of fulminant hepatic failure by hepatic volumetry, serial studies at least until 10–20 days after the onset of coma are necessary.     

Striking variability of hepatic copper levels in fulminant hepatic failure

Two cases of acute hepatic failure are reported in which the diagnosis of Wilson's disease was considered because of low serum ceruloplasmin, low serum copper levels and high 24 h urinary copper. Case 1 had Kayser-Fleischer rings, haemolysis and a high 24 h urinary copper, and so Wilson's disease was confidently diagnosed. Case 2 had high urinary copper excretion, but [64Cu] study indicated a 24:2 h ratio of 0.7 and made the diagnosis of Wilson's disease uncertain. Both patients underwent orthotopic hepatic transplantation, and multiple biopsies were taken from the resected specimen in order to estimate hepatic copper levels. In both cases, hepatic copper levels revealed considerable variation: 0.8-5.2 mumol/g dry wt (case 1) vs 0.02-12.65 mumol/g dry wt (case 2). In case 1, only two of 14 levels were within the diagnostic range for Wilson's disease (greater than 4 mumol/g dry wt), whereas hepatic copper levels in case 2 were in the Wilsonian disease range in three of 16 specimens. These results were in contrast to uniformly high hepatic copper levels in one patient with established cirrhosis secondary to Wilson's disease and two cases of primary biliary cirrhosis. This report indicates that hepatic copper levels vary greatly in acute liver failure, and that estimates from a single biopsy specimen may be misleading as to the cause of the underlying liver disease.     

数字连接试验等对亚临床肝性脑病诊断的意义

选择无肝硬化基础的肝功能衰竭患者,检测其并发亚临床肝性脑病(SHE)的情况,以了解肝功能与SHE的关系。1.对象:2001年7月至2002年1月本院住院患者,排除有肝硬化基础病例,选择肝功损害严重(总胆红素>171μmol/L)的病毒性肝炎患者32例,男30例,女2例,年龄20～58岁,平均36.53±10.60岁,凝血酶原活动度(PTA)<40％者10例。