Compound Danshen tablets downregulate amyloid protein precursor mRNA expression in a transgenic cell model of Alzheimer's disease Effects and a comparison with donepezil

After gene mutation, the pcDNA3.1/APP595/596 plasmid was transfected into HEK293 cells to establish a cell model of Alzheimer＇s disease. The cell model was treated with donepezil or compound Danshen tablets after culture for 72 hours. Reverse transcription-PCR showed that the mRNA expression of amyloid protein precursor decreased in all groups following culture for 24 hours, and that there was no significant difference in the amount of decrease between donepezil and compound Danshen tablets. Our results suggest that compound Danshen tablets can reduce expression of the mRNA for amyloid protein precursor in a transgenic cell model of Alzheimer＇s disease, with similar effects to donepezil.

Dominant-negative inhibition of glucose-dependent insulinotropic polypeptide impairs function of β cells in transgenic pigs

Dear Editor： Glucose-dependent insulinotropic polypeptide （GIP） and proglucagon product glucagon-like peptide-1 （GLP- 1） and their corresponding receptors promote secretion of glucose-dependent insulin and may be responsible for up to 70% of postprandial insulin secretions.

Expression of Hepatitis B Surface Antigen Gene in Ginseng Cells

The recombinant plasmid pBIBSa containing the HBsAg DNA fragment was transferred into Agrobacterium tumefaciens strain LBA4404 directly. Ginseng cells were transfected with A. tumefaciens carrying pBIBSa and the ginseng cell lines carrying HBsAg-S gene were obtained. The presence of target gene in the transfect cells was confirmed by PCR and RT-PCR. A clear band at the site of 700 bp was observed by agarose electrophoresis analysis of the samples containing the target gene. HBsAg expressed by the transgenic ginseng cells was detected by Western blot. Maximum expression levels of 184 ng HBsAg/g FW and 0. 009% of the total soluble proteins were observed by ELISA. HBsAg in ginseng cells was located both on the cell membrane and in the nuclei.

The Establishment of Double-Transgenic Mice that Co-Express the appA and MxA Genes Mediated by Type A Spermatogonia In vivo

Type A spermatogonial stem cells are the only immortal diploid cells in the postnatal animal that undergo self-renewal through the lifetime of an animal and transmit genes to subsequent generations. In this paper, the generation and characterization of double-transgenic mice co-expressing the Escherichia coli appA gene and human MxA gene generated via the in vivo transfection of type A spermatogonial cells were reported for the ifrst time. The dicistronic expression vector pcDNA-appA-MxA（AMP） and ExGen500 transfection reagent were injected into the testicular tissue of 7-d-old male ICR mice. The mice that underwent testis-mediated gene transfer were mated with wild-type female mice, and the integration and expression of the foreign genes in the offspring were evaluated. Transgenic mice that co-expressed appA and MxA showed a gene integration rate of 8.89%（16/180）. The transgenic mice were environmentally friendly, as the amount of phosphorous remaining in the manure was reduced by as much as 11.1%by the appA gene （P〈0.05）;these animals also exhibited a strong anti-viral phenotype.

NON-DESTRUCTIVE ANALYSIS OF THE NUCLEI OF TRANSGENIC LIVING CELLS USING LASER TWEEZERS AND NEAR-INFRARED RAMAN SPECTROSCOPIC TECHNIQUE

Transgenic cell lines of loblolly pine （Pinus taeda L.） were analyzed by a compact laser-tweezers-Raman-spectroscopy （LTRS） system in this investigation. A low power diode laser at 785 nm was used for both laser optical trapping of single transgenic cells and excitation for near-infrared Raman spectroscopy of the nuclei of synchronized cells, which were treated as single organic particles, at the S-phase of the cell cycle. Transgenic living cells with gfp and uidA genes were used as biological samples to test this LTRS technique. As expected, different Raman spectra were observed from the tested biological samples. This technique provides a high sensitivity and enables real-time spectroscopic measurements of transgenic cell lines. It could be a valuable tool for the study of the fundamental cell and molecular biological process by trapping single nucleus and by providing a wealth of molecular information about the nuclei of cells.

Post-transcriptional Gene Silencing Induced by Short Interfering RNAs in Cultured Transgenic Plant Cells

Short interfering RNA (siRNA) is widely used for studyingpost-transcriptional gene silencing and holds great promise as a tool for both identifying functionof novel genes and validating drug targets. Two siRNA fragments (siRNA-a and -b), which weredesigned against different specific areas of coding region of the same target green fluorescentprotein (GFP) gene, were used to silence GFP expression in cultured gfp transgenic cells of rice(Oryza sativa L.; OS), cotton (Gossypium hirsutum L.; GH), Eraser fir [Abies fraseri (Pursh) Poir;AF], and Virginia pine (Pinus virginiana Mill.; PV). Differential gene silencing was observed in thebombarded transgenic cells between two siRNAs, and these results were consistent with theinactivation of GFP confirmed by laser scanning microscopy, Northern blot, and siRNA analysis intested transgenic cell cultures. These data suggest that siRNA-mediated gene inactivation can be thesiRNA specific in different plant species. These results indicate that siRNA is a highly specifictool for targeted gene knockdown and for establishing siRNA-mediated gene silencing, which could bea reliable approach for large-scale screening of gene function and drug target validation.

Effect of Early Intervention with Extract of Huannao Yicong Decoction(还脑益聪方) on the Pathologic Picture of Hippocampus and Neurocyte Apoptosis in APP Transgenic Mice Model of Dementia

Objective：To observe the effect of early intervention using extract of Huannao Yicong Decoction （还脑益聪方,HYD） on the pathological picture of hippocampus,neurocyte apoptosis,and associated regulatory genes inβ-amyloid precursor protein（APP） transgenic mice model of dementia.Methods：Sixty APP695^（V7171） transgenic mice were randomly divided into four groups of 15.The model group was treated with distilled water, the positive control group was treated with donepezil（0.65 mg/kg）,and the two HYD groups were treated with high dose（2.8 g/kg） and low dose（1.4 g/kg） HYD,respectively.All testing drugs were administered through gastrogavage by dissolving in equal volume of distilled water,once a day for six successive months.In addition, a normal control group with 15 healthy C57BL/6J mice of the same age and genetic background was set up with distilled water treatment.The pathologic picture of brain tissue was observed by microscopy with HE stain;the amount of apoptosis cells in the hippocampal CA1 area was detected by TUNEL;and expressions of associated genes,Bcl-2,and Bax were determined by immunohistochemical method.Results：Pathologic pictures of hippocampus showed that in the model group,cells messily arranged,neurons markedly decreased, and the surrounding tissue of some cells was loosened with edema,necrosis,and widened gap with glia cells proliferation.Compared with those in the normal group,the amount of apoptosis cells in the CA1 area was increased,Bcl-2 expression decreased,and Bax expression increased significantly,with markedly reduced Bcl-2/Bax ratio in the model group.Compared to the model group,the pathological changes were significantly milder in the HYD-treated groups,showing rather regularly arranged cells,significantly increased neurons, only few denatured necrotic cells with milder edema,less proliferation of glia cells,and obviously reduced cell apoptosis in CA1 area（P0.05 or P0.01）.Besides,Bcl-2 expression was up-regulated and Bax expression down-regulated,and Bcl-2/Bax ratio significantly increased in the two HYD groups（P0.05 or P0.01）. Conclusion：Early intervention with HYD could improve the abnormal pathologic picture of hippocampus and regulate the expressions of associated genes to suppress cell apoptosis,which might be its mechanism of action in alleviating cognitive functional disorder.