人胚肝脂代谢相关基因的表达谱

运用cDNA微阵列结合荧光半定量聚合酶链反应技术，首次大规模分析人胚发育过程中肝脏脂代谢相关基因的表达情况，比较孕早、晚期人胚肝脂代谢相关基因的表达谱。抽提孕早、晚期胎儿肝脏组织总RNA，取等量mRNA逆转录标记33P，制成cDNA探针后与人类全基因cDNA微阵列芯片杂交，用相应软件分析杂交信号扫描结果。有差异表达的基因再用实时荧光半定量PCR方法进一步确认。在进入研究的可信基因中，与脂代谢相关的基因共有135条，其中28条有差异表达(2倍以上)，随胎龄增长，脂肪酸分解的相关基因呈现上调趋势，脂肪酸和胆固醇合成的相关基因呈现下调趋势，差异范围从0．43～8．3倍。检测15例胚肝组织的脂质含量，发现胆固醇和甘油三酯水平随胎龄增长而逐渐下降。人类胚胎肝脏的胆固醇和甘油三酯的合成率及含量可能随着发育成熟呈现下降趋势。     

Microarray-based gene expression profiling in pancreatic ductal carcinoma: status quo and perspectives

Background Pancreatic ductal adenocarcinoma has an extremely poor prognosis. To improve the prognosis, novel molecular markers and targets for earlier diagnosis and adjuvant and/or neoadjuvant treatment need to be identified. One of the key techniques that has been developed to achieve this goal is DNA microarray profiling, which is used to identify the mechanisms of deregulated molecular functions in pancreatic carcinoma cells.Objective As several studies using microarrays have already been published, this review attempts to compare published data and crossvalidate the results. In addition, the applied techniques are discussed.     

Identification of novel epididymal genes by expression profiling and in silico gene discovery

We have used both the UniGene RIKEN epididymal EST library and the Affymetrix microarray profiling for identifying novel epididymal genes in mouse. The use of ESTs is a complementary approach to Affymetrix arrays for identifying novel epididymal genes, while only 32% and 28% of ESTs of unknown genes were present in the U74v.2Set and MG 430 2.0 version Affymetrix arrays, respectively. As expected, the probe set for a notably larger proportion of known genes was present in the Affymetrix arrays, and the coverage was greatly improved by the newer array version. Furthermore, many genes with more than five ESTs in the UniGene library showed variable levels of expression in both versions of the Affymetrix arrays. However, both the Affymetrix and EST data correlated well with that obtained by quantitative RT-PCR, and thus, we conclude that the findings of high EST number but only limited expression in the arrays could be considered as false negatives in the Affymetrix arrays.     

The effect of early enteral nutrition supplemented with synbiotics on lipid and glucose homeostasis in critically ill patients: A randomized controlled trial

Background and aimsThe aim of the present study was to investigate the effects of gut microbiota modulation through synbiotic supplementation on lipid and glucose homeostasis in tube-fed critically-ill adult patients.MethodsThis study is placebo-controlled, parallel, single-center, double-blind clinical trial. 42 patients were randomly distributed in placebo and synbiotic groups to receive intervention for a maximum of 14 days. Serum levels of fasting glucose, total cholesterol, and triglycerides, insulin, and free fatty acids were obtained from blood sampling at baseline and the end of the study. Also, insulin resistance was determined by homeostasis model assessment of insulin resistance (HOMA-IR).ResultFasting glucose level (Day0 = 87.84 ± 15.51, Day14 = 83.76 ± 8.71 mg/dl, P = 0.51), fasting insulin level (Day0 = 9.46 ± 7.31, Day14 = 7.97 ± 5.19 mIU/L, P = 1.00), and HOMA index (Day0 = 1.89 ± 1.48, Day14 = 1.72 ± 1.17, P = 0.75) during the study were decreasing in both groups, but the decreases were not significant. Serum levels of total cholesterol, triglyceride, and free fatty acidsat the beginning of the study were 114.18 ± 43.43 mg/dl, 146.59 ± 53.99 mg/dl, 0.83 ± 0.57 mmol/L, and at the end of the study were 129.10 ± 39.05 mg/dl, 127.40 ± 91.88 mg/dl, 0.88 ± 0.77 mmol/L, respectively. None of these changes were significant either (P = 0.99, P = 0.38, P = 0.90, respectively).ConclusionsAccording to our findings, synbiotics supplementation in critically ill patients has no significant effect on lipid and glucose profile.     

Expression of iron regulatory genes in a rat model of hepatocellular carcinoma.

BACKGROUND/AIMS: The altered iron metabolism in hepatocellular carcinomas (HCCs), characterized by the iron-deficient phenotype, is suggested to be of importance for tumour growth. However, the underlying molecular mechanisms remain poorly understood. We asked whether these iron perturbations would involve altered expression of genes controlling iron homeostasis. METHODS: HCCs were induced in rats by the Solt and Farber protocol of chemical hepatocarcinogenesis, and to evaluate the effects of iron loading, one group of animals were supplemented with dietary iron during tumour progression. Tissue iron contents were determined, labelling indices of S-phase nuclei were calculated, and mRNA levels of iron-regulatory genes were quantitated. Protein levels of ferroportin1 were determined with Western blot. RESULTS: HCCs displayed reduced amount of tissue iron and lack of histologically stainable iron. HCCs expressed significantly higher mRNA levels of genes involved in iron uptake (transferrin receptor-1, divalent metal ion transporter-1), ferroxidase activity (Ferritin-H), and iron extrusion (ferroportin1). The protein levels of ferroportin1 in iron-deficient HCCs were similar as in control livers, and did not increase in HCCs exposed to iron. Hepcidin mRNA levels were decreased in iron-deficient HCCs, rose in response to iron loading and correlated to the tissue iron content. CONCLUSIONS: Taken together, the altered expressions of iron-regulatory genes in HCCs possibly reflect an increased demand for bioavailable iron and a high iron turnover in neoplastic cells.     

载脂蛋白E多态性与冠心病患者脂代谢的临床研究

目的研究载脂蛋白E(apoE)多态性与冠心病(CHD)及其脂代谢之间的关系。方法采用等电点聚焦电泳免疫印迹技术测定91例CHD及105例正常对照者的apoE表型,并用酶法测定他们的脂质水平。结果CHD组和对照组apoE表型分布及等位基因频率无显著性差异(P＞0．05)。CHD组不同apoE表型之间血脂水平比较发现,apoE基因多态性与胆固醇(TC)(P＜0．01)、低密度脂蛋白胆固醇(LDL-C)(P＜0．01)、甘油三酯(TG)(P＜0．05)有关,即E4等位基因携带者具有较高的TC和LDL-C水平,而E2等位基因携带者具有较低的TC和LDL-C水平。E2和E4等位基因携带者TG水平均升高。结论apoE基因多态性影响CHD患者的脂代谢,并通过影响脂代谢在CHD中起重要作用,但不是CHD的一个独立危险因素。     

大鼠肝癌细胞与胎肝细胞间抑癌微小RNAs的表达差异

微小RNAs(miRNAs)是一类短序列、非编码、具有调控功能的单链小分子RNA[1],通过与其靶mRNA分子互补结合,在翻译水平上特异性抑制基因表达,参与调控生物生长和发育等许多复杂的生命过程[2,3],异常的miRNAs表达可能与人类许多疾病乃至肿瘤的发生和发展都密切相关[3,4].已知的miRNAs参与癌症发生的机制包括细胞黏附、血管生成、蛋白质水解、细胞信号系统、细胞增殖、侵袭转移和细胞死亡[5].miRNAs在肝癌组织中异常表达,它可能参与了肝细胞癌变及肝癌转移的病理过程[6].本研究应用Exiqon miRNA基因芯片技术,建立大鼠肝癌细胞和胎肝细胞之间miRNAs的差异表达谱,探索肝癌诊断和预后的新指标.DOI:10.3760/cma.j.issn.1007-3418.2009.02.016     

Heart lipid accumulation in obese non-diabetic rats: effect of weight loss

Background and aimThe aim of this study was to investigate lipid content and expression of genes involved in lipid metabolism, in lean and obese non-diabetic rats and in obese rats undergoing food restriction and weight loss.Methods and resultsWe studied lean and genetically obese Zucker rats (fa/fa). Another group of obese rats were food restricted to lose 20% of initial body weight. We measured expression of genes involved in lipid oxidation and synthesis. Tissue triglyceride content, cell apoptosis and tissue fibrosis were also evaluated. The hearts of obese rats have higher triglyceride content compared to lean controls despite an increased expression of genes involved in fatty acid oxidation (PPARα, PGC-1α, CPT-I, ACO, UCP3). No differences were found in apoptosis and tissue fibrosis between the two phenotypes. Weight loss resulted in a significant reduction in heart lipid content, while the expression of genes involved in fatty acid oxidation remained elevated.ConclusionIn contrast to data reported in diabetic rats, pathways of lipid oxidation are increased rather than decreased in insulin-resistant obese rats. Food restriction reduced heart triglyceride content while lipid-oxidizing genes remained elevated, probably as a consequence of lipid oversupply coming from the endogenous source.     

壳聚糖、月见草、舒降之降血脂作用及机制研究

目的研究壳聚糖、月见草、舒降之的降血脂作用及机制。方法运用新西兰家兔制备高脂血症模型,各实验组分别同时饲喂壳聚糖、月见草、舒降之10周,然后分别测定给药前、后血脂水平的变化,并提取肝组织和肾皮质组织蛋白,用免疫印迹法观察受体相关蛋白的表达水平变化。结果壳聚糖、月见草与舒降之都可使血脂不同程度下降,高脂饮食加壳聚糖组实验动物肾、肝脏组织中受体相关蛋白表达水平较其他各组明显增高。结论壳聚糖、月见草、舒降之均具有一定的降血脂作用,调节受体相关蛋白RAP的表达可能是机制之一。     

Expression of homeodomain protein CDX2 in gallbladder carcinomas

Purpose Caudal-related homeobox protein CDX2 plays an important role in the regulation of cell proliferation and differentiation of the intestinal epithelium. CDX2 is associated with intestinal metaplasia and carcinomas of the stomach, but the role of CDX2 in gallbladder carcinogenesis remains unknown.Methods We analyzed the expression of CDX2 and intestinal apomucin MUC2 in gallbladder cancer cell lines at the mRNA level by the RT-PCR method. We also investigated the expression of CDX2 and MUC2 in 68 primary gallbladder carcinomas by the immunohistochemical staining method and compared the expression of CDX2 with the clinicopathological factors in the gallbladder carcinoma cases.Results Expression of CDX2 and MUC2 was found in three of four gallbladder cancer cell lines at the mRNA level. In addition, we found that CDX2 was absent in the normal gallbladder epithelium, but the CDX2 protein was expressed in 25 of the 68 (36.8%) gallbladder carcinomas. Interestingly, in the tubular type gallbladder carcinomas, the frequency of CDX2 expression was much higher in the well-differentiated type than the moderately and poorly differentiated types, the difference being statistically significant (P<0.01). CDX2 expression showed a relationship with expression of MUC2 (P<0.04) in the gallbladder carcinomas. CDX2 was expressed in intestinal metaplasia and dysplasia, which are hypothesized to be premalignant conditions.Conclusion These results imply that CDX2 plays an important role in gallbladder carcinogenesis with intestinal differentiation.     

铁稳态在血管钙化发病机制中的作用

心血管疾病(CVD)在全球范围具有高发病率、高致残率和高致死率的特点,而血管钙化(VC)是造成CVD风险事件终末结局的主要共同病理改变,表明血管钙化是CVD的潜在防治靶点,但鉴于血管钙化的复杂发病机制,目前没有应对血管钙化的有效手段。铁是人体必需的微量元素,研究发现铁含量超载或缺乏导致的铁稳态(IH)异常分别在不同类型的CVD和疾病不同阶段参与血管钙化的发生发展。因此,阐明血管钙化时的铁稳态异常机制,有助于为血管钙化的基础研究和临床防治指出新方向。     

Molecular Signatures of Lymphoma

Hematologic malignancies have historically been characterized by morphologic, immunophenotypic, molecular, and genetic features. However, morphologically identical tumors can have clearly distinct clinical outcomes, suggesting underlying biological heterogeneity. Recent advances in microarray technology have helped the classification of lymphoid malignancies evolve to a new refined level. In addition to the discovery of new disease subclasses defined by unique molecular profiles, gene expression patterns can be correlated with specific genetic abnormalities and prognoses. Furthermore, the discovery of new disease subtypes has provided further insight into lymphoma biology and pathogenesis. Unique gene signatures can highlight key deregulated pathways that are active in molecular disease categories, and in some cases these findings have elucidated new targets for novel therapeutic approaches. This review summarizes the current status of molecular profiling in non-Hodgkin lymphomas. In this review, we have endeavored to include data from multiple investigator groups and tried to cover the breadth of lymphoid tumors, excluding acute and chronic leukemias.