Improved detection of hepatocyte proliferation using antibody to the pre-replication complex: an association with hepatic fibrosis and viral replication in chronic hepatitis C virus infection

Summary. To test the hypothesis that hepatitis C virus (HCV) might induce hepatocyte proliferation directly, thereby predisposing HCV carriers to cirrhosis and hepatocellular carcinoma, we have used a new method to identify proliferating hepatocytes, employing a novel monoclonal antibody to minichromosome maintenance (Mcm) proteins, essential components of the pre-replication complex. Antibody to Ki-67, a conventional marker of cell division, was also studied. Eighty-seven patients with chronic HCV infection and a broad spectrum of histological change were studied. Proliferation was observed rarely in hepatocytes from normal liver from healthy controls (always less than 0.01%). However, proliferating hepatocytes were detected in all HCV-infected patients and the proportion of hepatocytes expressing Mcm-2 (3–40%) always exceeded that expressing Ki-67 (1–14%) and correlated positively with increasing stage of fibrosis ( P  = 0.0001) and viral replication ( P  = 0.0004). There were weaker but significant associations between the proportion of hepatocytes expressing Mcm-2 and inflammatory indices including interface hepatitis, portal tract inflammation, lobular inflammation and steatosis. There was no association between the proportion of hepatocytes expressing Mcm-2 and age, gender or past alcohol consumption, but there was a weak association with current consumption of alcohol ( P  = 0.0067). The proportion of Ki-67 hepatocytes did not correlate with any clinical, laboratory or histological parameter. Mcm-2 was also detected in bile duct cells, sinusoidal lining cells and infiltrating lymphocytes, but at low frequency. These data indicate first, that Mcm-2 is a more sensitive marker of hepatocyte proliferation than Ki-67, second that many hepatocytes in chronic HCV infection have entered the cell cycle and third, suggest that interference with the hepatocyte cell cycle might be an alternative approach to therapy.     

Effect of mutant p27(kipl) gene on human cholangiocarcinoma cell line, QBC(939)

AIM：To investigate the effects of exogenously mutated p27^kip1 （p27） on proliferation and apoptosis of human cholangiocarcinoma cell line, QBC939 in vivo.METHODS： Adenviral vectors were used to transfect mutated p27 cDNA into human QBC939 cell line. Expression of p27 was detected by RT-PCR. Western blot. Cell growth, morphological change, cell cycle, apoptosis and cloning formation were determined by MTT assay and flow cytometry.RESULTS： The expression of p27 protein and mRNA was increased signifi cantly in QBC939 cell line transfected with Ad-p27mt. The transfer of Ad-p27mt could signifi cantly inhibit the growth of QBC939 cells, decrease the cloning formation rate and induce apoptosis. p27 over expression caused cell cycle arrest at G0/G1 phase 72 h after infection with Ad-p27mt.CONCLUSION： p27 may cause cell cycle arrest at G0/G1 phase and subsequently lead to apoptosis. Recombinant adenovirus expressing mutant p27 may be potentially useful in gene therapy for cholangiocarcinoma.     

大鼠胸主动脉球囊损伤后平滑肌细胞PCNA和P27表达的变化

目的探讨大鼠胸主动脉球囊损伤后增殖细胞核抗原(PCNA)、细胞周期蛋白依赖性激酶抑制蛋白P27表达变化规律。方法30只400～500g的雄性SD大鼠随机分为2组。手术组(n=24)行球囊损伤大鼠胸主动脉术;对照组(n=6)不行球囊损伤,作为正常对照。于术后2d、7d、14d、28d取胸主动脉应用HE染色、免疫组化和计算机图像分析法进行形态学、PCNA和P27表达水平检测。结果(1)正常动脉壁不表达PCNA,球囊损伤后开始表达,术后2d时中膜表达显著(24.08±2.35);术后7d出现新生内膜,PCNA在内膜高度表达(35.32±3.46)而中膜表达已明显下降(9.47±1.56);后内膜、中膜表达均逐渐下降,28d时形成显著的新生内膜(0.173±0.030)mm2,管腔狭窄;(2)正常动脉壁显著表达P27(19.29±1.54),球囊损伤后中膜表达迅速下降,2d达最低水平(2.93±0.55),后逐渐回升;14d、28d新生内膜中可见P27表达,并逐渐增多;(3)P27表达与PCNA表达呈显著负相关(r=0.868P<0.001)。结论球囊损伤大鼠主动脉后管壁P27表达下调伴随PCNA表达上调,血管平滑肌细胞恢复增殖能力并向内膜下迁移并过度增殖,从而形成显著的新生内膜、管腔狭窄。     

Malignant degeneration of Barrett''s esophagus: the role of the Ki-67 proliferation fraction, expression of E-cadherin and p53

Barrett's columnar epithelium with dysplasia is the most important risk factor for adenocarcinoma of the distal esophagus. The molecular mechanisms responsible for progression of columnar metaplasia to dysplasia and invasive carcinoma are mostly unknown. We investigated expression of the tumor suppressor gene p53, E-cadherin expression and cell proliferation in the metaplasia-dysplasia-carcinoma sequence of esophageal adenocarcinoma. In 24 patients with R0-resected adenocarcinomas of the distal esophagus we evaluated the expression of E-cadherin (antibody HECD-1), mutated p53 (antibody DO1) and cell proliferation (antibody MiB1) by immunohistochemistry in sections of adenocarcinoma, columnar metaplasia, with and without dysplasia, and in squamous epithelium of the esophagus. No p53 immunoreactivity was seen in sections of normal squamous epithelium or columnar metaplasia. Fifty per cent of invasive adenocarcinomas stained positive for mutated p53. The p53 expression correlated with the T-category (P = 0.048) and the N-category (P = 0.024). There was a significant decrease in the expression of E-cadherin from columnar metaplasia to dysplasia and to esophageal adenocarcinoma (P < 0.0001). Expression of E-cadherin in columnar metaplasia without dysplasia was similar to that seen in normal squamous epithelium of the esophagus. The Ki-67 proliferation fraction increased significantly from normal squamous epithelium to columnar metaplasia to dysplasia and to invasive carcinoma (P < 0.001), with a marked expansion of the proliferative component. There was no correlation between cell proliferation, E-cadherin expression and the tumor stage. In contrast to the alterations in the p53 expression, a decreased E-cadherin expression and the expansion of the proliferative component represent an early phenomenon in the malignant degeneration of Barrett's esophagus. This might aid in the early detection of esophageal adenocarcinoma.     

Modular patterning of structure and function of the striatum by retinoid receptor signaling

Retinoid signaling plays a crucial role in patterning rhombomeres in the hindbrain and motor neurons in the spinal cord during development. A fundamentally interesting question is whether retinoids can pattern functional organization in the forebrain that generates a high order of cognitive behavior. The striatum contains a compartmental structure of striosome (or "patch") and intervening matrix. How this highly complex mosaic design is patterned by the genetic programs during development remains elusive. We report a developmental mechanism by which retinoid receptor signaling controls compartmental formation in the striatum. We analyzed RARbeta(-/-) mutant mice and found a selective loss of striosomal compartmentalization in the rostral mutant striatum. The loss of RARbeta signaling in the mutant mice resulted in reduction of cyclin E2, a cell cycle protein regulating transition from G(1) to S phase, and also reduction of the proneural gene Mash1, which led to defective neurogenesis of late-born striosomal cells. Importantly, during striatal neurogenesis, endogenous levels of retinoic acid were spatiotemporally regulated such that transduction of high levels of retinoic acid through RARbeta selectively expanded the population of late-born striosomal progenitors, which evolved into a highly elaborate compartment in the rostral striatum. RARbeta(-/-) mutant mice, which lacked such enlarged compartment, displayed complex alternations of dopamine agonist-induced stereotypic motor behavior, including exaggeration of head bobbing movement and reduction of rearing activity. RARbeta signaling thus plays a crucial role in setting up striatal compartments that may engage in neural circuits of psychomotor control.     

罗格列酮对大鼠颈动脉球囊损伤后平滑肌细胞增殖和调亡的影响

目的观察罗格列酮对大鼠颈动脉损伤后平滑肌细胞增殖和凋亡的影响。方法SD大鼠随机分为3组,即对照组、手术组、治疗组。手术组及治疗组均给予左侧颈总动脉球囊损伤,治疗组给予罗格列酮灌胃治疗。术后2周取损伤血管行HE染色及光镜观察,计算内膜面积（NIA）、内弹力板围绕面积（IELA）及管腔狭窄指数（SI）。免疫组化法检测平滑肌细胞增殖率,Tunnel法检测平滑肌细胞凋亡率。结果术后2周,手术组内膜面积、管腔狭窄指数显著高于对照组（P<0.01）;经治疗后,治疗组内膜面积、管腔狭窄指数显著低于手术组（P<0.01）。手术组细胞增殖率显著高于对照组（P<0.01）,而治疗组细胞增殖率显著低于手术组（P<0.01）。手术组细胞凋亡率显著低于对照组（P<0.01）,而治疗组细胞凋亡率显著高于手术组（P<0.01）。结论罗格列酮可以促进血管平滑肌细胞凋亡,抑制其增殖,从而减轻损伤血管的再狭窄。     

脱氢表雄酮对氧化型低密度脂蛋白诱导的血管平滑肌细胞中血管细胞粘附分子1表达的影响

目的探讨脱氢表雄酮对氧化型低密度脂蛋白诱导的血管平滑肌细胞分泌血管细胞粘附分子1的影响。方法用脱氢表雄酮(5μmol/L)作用于氧化型低密度脂蛋白(50 mg/L)诱导的体外培养的SD大鼠血管平滑肌细胞,采用免疫细胞化学、免疫蛋白印迹法、逆转录聚合酶链反应检测其血管细胞粘附分子1蛋白及mRNA的表达。结果当细胞培养基中加入氧化型低密度脂蛋白后,血管平滑肌细胞血管细胞粘附分子1的分泌明显升高(P<0.05),而同时加入脱氢表雄酮可使血管细胞粘附分子1的分泌降低(P<0.05)。结论脱氢表雄酮能够抑制氧化型低密度脂蛋白诱导的血管平滑肌细胞血管细胞粘附分子1的分泌,而且可能是脱氢表雄酮抗动脉粥样硬化的机制之一。     

血管内皮生长因子基因转染骨髓间充质干细胞移植促进缺血心肌血管生成的研究

目的研究血管内皮生长因子(vascularendothelial growth factor,VEGF)基因转染骨髓间充质干细胞(mesenchymalstem cells,MSCs)移植对缺血心肌的血管生成作用。方法于2004年5月至2005年8月取第四军医大学西京医院分离、培养Wistar大鼠的MSCs,用真核表达载体pcDNA3.1(-)/hVEGF165转染MSCs。45只近交系Wistar大鼠随机均分为转染组(MSCs/VEGF组)、对照组(MSCs组)、无血清培养基组(DMEM组),结扎前降支建立急性心肌梗死模型后在梗死区边缘区行5×106细胞移植,DMEM组行等量培养基注射。细胞移植前行CM-DiI标记。移植1个月后行心脏B超测量射血分数值,组织化学染色评价新生血管密度。结果培养的MSCs呈典型贴壁生长成纤维样外观,pcDNA3.1(-)/hVEGF165能有效转染大鼠MSCs,移植1个月后MSCs/VEGF组较其余各组左室射血分数(LVEF),再生血管密度明显增加,差异均有显著性(P<0.01)。结论VEGF基因转染MSCs移植能显著促进缺血心肌血管再生,进而改善心脏功能。     

A method for enzymatic dissociation of cells from isolated pancreatic islets

Summary An enzymatic method for isolation of single cells from the islets of Langerhans is described. The isolated cells appeared well preserved and survived for at least 7 days when maintained in culture. The dry mass of the isolated islet cells was found to be decreased 30 min after administration of alloxan to obese-hyperglycemic mice. Isolated individual islet cells from obese-hyperglycemic mice had a higher dry mass than those from their lean litter mates. Traduzione a cura di G. U.