导入针对survivin基因的siRNA对大肠癌Lovo细胞凋亡和增殖的影响

目的：向大肠癌离体LOVO细胞中导入针对survivin基因的siRNA，并研究其对LOVO细胞凋亡的影响。方法：设计2条特异性针对survivin基因的siRNA，并体外转录法合成，利用脂质体导入LOVO细胞并检测转染后细胞的凋亡和增殖情况。结果：RTPCR检测survivin mRNA表达水平发现两RNA干扰组细胞内survivin mRNA表达量明显低于正常LOVO细胞；细胞凋亡检测结果发现两干扰组细胞凋亡率分别为21、5％和26、28％明显高于正常Lovo细胞；细胞增殖结果显示：两干扰组细胞增殖能力比正常Lovo细胞减弱。结论：针对survivin基因的siRNA能有效降低目的基因的mRNA表达，抑制LOVO细胞生长，细胞凋亡率明显增高。为大肠癌基因治疗的可行性提供了有力的证据。     

Gamma-aminobutyric acid promotes human hepatocellular carcinoma growth through overexpressed gamma-aminobutyric acid A receptor α3 subunit

AIM：To investigate the expression pattern of gamma-aminobutyric acid A（GABAA） receptors in hepatocellular carcinoma（HCC） and indicate the relationship among gamma-aminobutyric acid（GABA）,gamma-aminobutyric acid A receptor α3 subunit（GABRA3） and HCC.METHODS：HCC cell line Chang,HepG2,normal liver cell line L-02 and 8 samples of HCC tissues and paired non-cancerous tissues were analyzed with semiquantitative polymerase chain reaction（PCR） for the expression of GABAA receptors.HepG2 cells were treated with gamma-aminobutyric acid（GABA） at serial concentrations（0,1,10,20,40 and 60 μmol/L）,and their proliferating abilities were analyzed with the 3-（4,5-methylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） assay,cell doubling time test,colon formation assay,cell cycle analysis and tumor planted in nude mice.Small interfering RNA was used for knocking down the endogenous GABRA3 in HepG2.Proliferating abilities of these cells treated with or without GABA were analyzed.RESULTS：We identified the overexpression of GABRA3 in HCC cells.Knockdown of endogenous GABRA3 expression in HepG2 attenuated HCC cell growth,suggesting its role in HCC cell viability.We determined the in vitro and in vivo effect of GABA in the proliferation of GABRA3-positive cell lines,and found that GABA increased HCC growth in a dose-dependent manner.Notably,the addition of GABA into the cell culture medium promoted the proliferation of GABRA3-expressing HepG2 cells,but not GABRA3-knockdown HepG2 cells.This means that GABA stimulates HepG2 cell growth through GABRA3.CONCLUSION：GABA and GABRA3 play important roles in HCC development and progression and can be a promising molecular target for the development of new diagnostic and therapeutic strategies for HCC.     

Targeting ie-1 gene by RNAi induces baculoviral resistance in lepidopteran cell lines and in transgenic silkworms

RNA interference (RNAi)-mediated viral inhibition has been used in a few organisms for eliciting viral resistance. In the present study, we report the use of RNAi in preventing baculovirus infection in a lepidopteran. We targeted the baculoviral immediate early-1 (ie-1) gene in both a transformed lepidopteran cell line and in the transgenic silkworm Bombyx mori L. Constitutive expression of double-stranded RNA was achieved by piggyBac-mediated transformation of Sf9 cell line with a transgene encoding double-stranded ie-1 RNA (dsie-1). Strong viral repression was seen at early stages of infection but subsequent recovery of viral proliferation was observed. In contrast, the same transgene inserted into the chromosomes of transgenic silkworms induced long-term inhibition of B. mori nucleopolyhedrovirus infection, with nearly 40% protection compared with nontransgenic animals. Protection was efficient at larval stages after oral infection with occlusion bodies or hemocoel injection of budded viruses. Virus injected pupae also displayed resistance. These results show that heritable RNAi can be used to protect silkworm strains from baculovirus infection.     

RNAi阻断pax5基因的表达对B系恶性淋巴瘤细胞生物学特性的影响

本研究目的在于了解pax5基因对B系血液肿瘤细胞的免疫表型、细胞增殖及凋亡等生物学特性的影响。应用体外转录RNAi方法合成pax5特异的shRNA，用实时荧光定量PCR和Western blot技术评价基因沉默效果、筛选有效的shRNA，利用流式细胞术、MTT实验以及real—timePCR等技术检测沉默前后细胞免疫表型、增殖、凋亡等变化。结果表明：应用体外转录RNAi方法合成的shRNA抑制了B系恶性淋巴瘤细胞株中pax5在mRNA和蛋白水平的表达；pax5阻断表达后的淋巴瘤细胞免疫表型发生了变化，信号分子CD19的mRNA和蛋白表达水平均相应降低，而细胞膜表面分子IgM未发生明显改变；pax5的沉默表达对淋巴瘤细胞增殖效率和凋亡的影响无显著性差异（P〉0.05）．结论：pax5基因对B细胞的晚期分化起着重要作用，pax5基因可能参与淋巴瘤细胞的信号转导，未检测到pax5瞬时缺失表达对淋巴瘤细胞生长增殖及凋亡的影响，对其机制有必要进一步深入研究，     

Cytokines and peroxisome proliferator-activated receptor gamma ligand regulate phagocytosis by pancreatic stellate cells

BACKGROUND & AIMS: Pancreatic stellate cells have been characterized as the major source of extracellular matrix and cytokine production in the pancreas. This study showed that pancreatic stellate cells have a phagocytic function. METHODS: The morphological features of periacinar phagocytic cells were investigated by immunohistochemically staining serial sections of the pancreas from male WBN/Kob rats and an animal model of acute pancreatitis for glial fibrillary acidic protein and alpha-smooth muscle actin. Pancreatic stellate cells were assayed for phagocytic activity by incubating them with senescent polymorphonuclear neutrophils or fluorescence-labeled latex beads in the presence or absence of cytokines, growth factors, and peroxisome proliferator-activated receptor gamma ligand. The role of CD36 and peroxisome proliferator-activated receptor gamma in phagocytosis was investigated by blocking endogenous CD36 and peroxisome proliferator-activated receptor gamma activity with anti-CD36 antibody and peroxisome proliferator-activated receptor gamma small interfering RNAs, respectively. RESULTS: Phagocytic cells were observed in areas of inflammation, and they were identical to the glial fibrillary acidic protein-positive and alpha-smooth muscle actin-positive cells, thus suggesting that they were pancreatic stellate cells. Aged polymorphonuclear neutrophils were ingested into the cytoplasm of the pancreatic stellate cells. Transforming growth factor beta, tumor necrosis factor alpha, and interleukin 1beta decreased the phagocytic activity of pancreatic stellate cells, whereas troglitazone induced a dose-dependent increase in both phagocytic activity and expression of CD36. Blockade of CD36 reduced troglitazone-induced phagocytosis. Silencing of the peroxisome proliferator-activated receptor gamma gene decreased phagocytosis and expression of CD36. CONCLUSIONS: Pancreatic stellate cells act as resident phagocytic cells, and CD36 promotes troglitazone-induced phagocytic activity via peroxisome proliferator-activated receptor gamma transactivation. Because phagocytosis is essential to limit the extent of inflammation, enhancement of phagocytic activity may provide an important approach to the treatment of pancreatic diseases.     

应用siRNA抑制由醛固酮诱导的大鼠肥大心肌细胞中钙调神经磷酸酶AβmRNA的表达

目的:本研究通过应用RNA干扰的方法,观察了钙调神经磷酸酶（CaN）在醛固酮（A ld）诱导的大鼠心肌细胞肥大时其AβmRNA表达水平。方法:在A ld诱导心肌细胞肥大模型上同时转染CaN AβmRNA靶标siRNA及其阴性对照进行转染。通过免疫荧光染色及RT-PCR方法检测CaN Aβ蛋白及mRNA的表达,同时测定心肌细胞面积变化。结果:A ld组CaN AβmRNA表达较对照组显著升高,细胞表面积显著增加;CaN AβmRNA靶标siRNA组细胞浆中绿色荧光表达比siRNA阴性对照组少,即CaN蛋白表达量siRNA组较siRNA阴性对照组减少,RT-PCR检测结果显示siRNA组CaN AβmRNA表达较siRNA阴性对照组受到明显抑制,细胞面积siRNA阴性对照组较siR-NA组增加。结论:siRNA可抑制钙调神经磷酸酶AβmRNA的表达,对于心肌细胞中基因功能的研究,RNA干涉可以作为应用工具。     

A novel Toll like receptor with two TIR domains (HcToll-2) is involved in regulation of antimicrobial peptide gene expression of Hyriopsis cumingii

Animal Toll-like receptors (TLRs) are involved in innate immunity. Toll proteins are generally transmembrane proteins. In this study, an atypical Toll-like receptor (HcToll-2) was identified from the triangle-shell pearl mussel Hyriopsis cumingii, which belongs to phylum Mollusca. Unlike the typical Toll like receptors with extracellular leucine-rich repeats (LRRs), transmembrane, and intracellular Toll/interleukin-1 receptor (TIR) domains, HcToll-2 has two homologous TIR domains located at the C-terminal (designated as HcTIR1 and HcTIR2) and lacks a transmembrane domain. Phylogenetic analysis showed that HcTIR1 was clustered with TIR of sea anemone Toll, and HcTIR2 was clustered with TIR of Drosophila Toll. HcToll-2 mRNA could be detected in the hepatopancreas and was upregulated after challenge with Escherichia coli and Staphylococcus aureus. Recombinant HcLRR protein with GST tag could bind to bacteria and also to LPS and PGN. Over-expression of both HcTIR1 and HcTIR2 induced drosomycin genes in Drosophila S2 cells. RNAi analysis showed that HcToll-2 was required for the expression of theromacin, which is a cysteine-rich antimicrobial peptide (AMP) gene. This research is the first report of an atypical Toll-like receptor HcToll-2 involved in antibacterial immunity through induction of AMP expression.     

Cellular immune responses against viral pathogens in shrimp

Shrimp is one of the most important commercial marine species worldwide; however, viral diseases threaten the healthy development of shrimp aquaculture. In order to develop efficient control strategies against viral diseases, researchers have begun focusing increasing attention to the molecular mechanism of shrimp innate immunity. Although knowledge of shrimp humoral immunity has grown significantly in recent years, very little information is available about the cell-mediated immune responses. Several cellular processes such as phagocytosis, apoptosis, and RNA interference critical in cellular immune response play a significant role in endogenous antiviral activity in shrimp. In this review, we summarize the emerging research and highlight key mediators of cellular immune response to viral pathogens.     

Effects of lentiviral-mediated Foxp1 and Foxq1 RNAi on the hepatocarcinoma cell

Foxp1 and Foxq1 are two multifunctional molecules of “forkhead box (Fox)” family. The objective of this paper was to construct the lentiviral vectors expressing RNA interference (RNAi) against Foxp1 or Foxq1 genes, and the effects of both vectors with two RNAis on the proliferation, migration and apoptosis of 7721 hepatocarcinoma cell line were evaluated. Six target sequences against human Foxp1/Foxq1 mRNA were designed respectively and six pairs of their corresponding double-strand DNA oligo (siRNA) were synthesized prior to being transfected into 7721 cells with lipo2000, then a most efficient siRNA were selected to be subcloned into pLL3.7-GFP/Lenti plasmids. These plasmids were transfected into 293T cells to package lentiviral particles for subsequent transfection into 7721 cells after their sequences were confirmed. The expression of Foxp1and Foxq1 genes in the transfected cells were identified by real-time PCR. The migration, infiltration, viability and apoptosis of the transfected cells were assessed by wound healing assay, Transwell assay, CCK-8 assay and flow cytometry. Sequencing results showed that lentiviral vectors contained Foxp1 or Foxq1 gene. After being transfected into 7721 cells, Foxp1 and Foxq1 expression were significantly down-regulated by siRNA-823 and siRNA-834. The migration and infiltration ability, and the viability of 7721 cells transfected with two siRNAs were significantly suppressed; flow cytometry assay exhibited the apoptosis rate of transfected 7721 cells with the lentivirus RNAi vector of Foxp1 or Foxq1 was increased. All the results showed that the lentivirus RNAi vectors of Foxp1 and Foxq1 were able to inhibit the expression of Foxp1 and Foxq1 in 7721 cells efficiently, and the down-regulation of either Foxp1 or Foxq1 resulted in suppression of migration, infiltration and viability of 7721 cells and an increase in cell apoptosis. Our data indicated that both Foxp1 and Foxq1 genes played an oncogenic role in hepatocarcinoma cells, which proposed the two genes as new therapeutic targets for the cancer.