一种新的肝细胞生成素（HPO）转录本及其生物学活性

利用 5′RACE技术从人胎肝组织中分离一种新形式的肝细胞生成素 (HPO 2 0 5 )cDNA ,其编码蛋白质氨基酸序列的N端较已报道的人肝细胞生成素HPO(hepatopoietin)多 80个氨基酸 ,推测其蛋白质分子量为 2 3kD。RT PCR检测HPOmRNA在多种肝癌细胞中表达 ,Western印迹可检测到 2 3kDHPO 2 0 5表达 ,表明此种形式HPO在自然状态下存在。将构建的HPO 2 0 5真核表达载体转染入COS 7细胞 ,其表达蛋白质能够刺激HepG2肝癌细胞DNA合成 ;将HPO 2 0 5、HPO和荷空表达载体分别转染入低水平表达HPO的Bel 740 2肝癌细胞株 ,发现HPO 2 0 5比HPO具有较强的激活MAPK磷酸化的活性。细胞周期分析稳定转染HPO 2 0 5 ,HPO细胞的增殖周期也支持这一结论。这些结果表明HPO 2 0 5具有刺激肝源性细胞增殖的活性 ,并提示HPO 2 0 5可能较HPO有更强的生物学活性     

Effect of mesenchymal stem cells-derived exosomes on tumor microenvironment: Tumor progression versus tumor suppression

Mesenchymal stem cells (MSCs) are multipotent cells with the potential to differentiate into different cell types. Owing to their immunosuppressive and anti-inflammatory properties, they are widely used in regenerative medicine, but they have a dual effect on cancer progression and exert both growth-stimulatory or -inhibitory effects on different cancer types. It has been proposed that these controversial effects of MSC in tumor microenvironment (TME) are mediated by their polarization to proinflammatory or anti-inflammatory phenotype. In addition, they can polarize the immune system cells that in turn influence tumor progression. One of the mechanisms involved in the TME communications is extracellular vesicles (EVs). MSCs, as one of cell populations in TME, produce a large amount of EVs that can influence tumor development. Similar to MSC, MSC-EVs can exert both anti- or protumorigenic effects. In the current study, we will investigate the current knowledge related to MSC role in cancer progression with a focus on the MSC-EV content in limiting tumor growth, angiogenesis, and metastasis. We suppose MSC-EVs can be used as safe vehicles for delivering antitumor agents to TME.     

GPR40 is expressed in glucagon producing cells and affects glucagon secretion

The free fatty acid receptor, GPR40, has been coupled with insulin secretion via its expression in pancreatic beta-cells. However, the role of GPR40 in the release of glucagon has not been studied and previous attempts to identify the receptor in alpha-cells have been unfruitful. Using double-staining for glucagon and GPR40 expression, we demonstrate that the two are expressed in the same cells in the periphery of mouse islets. In-R1-G9 hamster glucagonoma cells respond dose-dependently to linoleic acid stimulation by elevated phosphatidyl inositol hydrolysis and glucagon release and the cells become increasingly responsive to fatty acid stimulation when overexpressing GPR40. Isolated mouse islets also secrete glucagon in response to linoleic acid, a response that was abolished by antisense treatment against GPR40. This study demonstrates that GPR40 is present and active in pancreatic alpha-cells and puts further emphasis on the importance of this nutrient sensing receptor in islet function.     

Genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody in Iran

During 2010–14 surveys in the major sesame growing areas of Fars, Yazd and Isfahan provinces (Iran), genetic diversity and vector transmission of phytoplasmas associated with sesame phyllody were studied. Virtual RFLP, phylogenetic, and DNA homology analyses of partial 16S ribosomal sequences of phytoplasma strains associated with symptomatic plants revealed the presence of phytoplasmas referable to three ribosomal subgroups, 16SrII-D, 16SrVI-A, and 16SrIX-C. The same analyses using 16S rDNA sequences from sesame phyllody-associated phytoplasmas retrieved from GenBank database showed the presence of phytoplasmas clustering with strains in the same subgroups in other Iranian provinces including Bushehr and Khorasan Razavi. Circulifer haematoceps and Orosius albicinctus, known vectors of the disease in Iran, were tested for transmission of the strains identified in this study. C. haematoceps transmitted 16SrII-D, 16SrVI-A, and 16SrIX-C phytoplasmas, while O. albicinctus only transmitted 16SrII-D strains. Based on the results of the present study and considering the reported presence of phytoplasmas belonging to the same ribosomal subgroups in other crops, sesame fields probably play an important role in the epidemiology of other diseases associated with these phytoplasmas in Iran.     

Evaluation of ARG protein expression in mature B cell lymphomas compared to non-neoplastic reactive lymph node

The participation of Abl-Related Gene (ARG) is demonstrated in pathogenesis of different human malignancies. However there is no conclusive evidence on ARG expression level in mature B cell lymphomas. In this study we evaluated ARG protein expression in Follicular Lymphoma (FL), Burkitt’s Lymphoma (BL) and Diffused Large B Cell Lymphoma (DLBCL) in comparison with non-neoplastic lymph nodes. Semi-quantitative fluorescent ImmunoHistoChemistry was applied on 14, 7 and 4 patients with DLBCL, FL and BL respectively, adding to 4 normal and 4 reactive lymph nodes. The mean ratio of ARG/GAPDH expression was significantly different (p < 0.00) between lymphomas and control samples, with DLBCL having the highest ARG expression amongst all. Over expression of ARG was seen in FL and BL, with FL expressing statistically more ARG than BL. Moreover, the ARG/GAPDH expression ratio increased from DLBCL stage I towards stage VI, all showing significantly more ARG expression than FL and BL (in all cases p < 0.00).     

Analysis of the molecular variation between and within cultivated and wild Pistacia species using AFLPs

Knowledge of pistachio genetic diversity is necessary for the formulation of appropriate management strategies for the conservation of these species. We analysed amplified fragment length polymorphisms in a total of 216 pistachio accessions, which included seven populations from three wild species (Pistacia vera, Pistacia khinjuk and Pistacia atlantica subsp. kurdica) and most of the important cultivars from Iran, together with some foreign cultivars. High levels of genetic diversity were detected within the Iranian cultivars, and they showed a clear separation from foreign cultivars, as revealed by unweighted pair group method with arithmetic averaging and supported by analysis of molecular variance. The lowest amount of polymorphism was observed in P. atlantica subsp. kurdica, which showed the lowest number of total bands as compared to the other species. This revealed strong genetic erosion of P. atlantica subsp. kurdica, which reflected a severe decline in habitat and over-exploitation. Based on these findings, strategies are proposed for the genetic conservation and management of pistachio species and cultivars.