Han-sen Wang | PubMed Health

PubMed2006

[Knocking down rat Mecp2 expression by RNAi].

OBJECTIVE: To find the valid siRNA (small interference RNA) sequence to knock down rat Mecp2 expression for the analysis of Mecp2 function by RNA interference (RNAi). METHODS: A plasmid (pMecp2-RFP) expressing rat Mecp2 and marker gene red fluorescent protein (RFP) as a fusion gene was constracted. We first selected a candidate valid sequence by cotransfecting the pMecp2-RFP with 4 candidate siRNAs targeting rat Mecp2 to HEK293T cells respectively, and then identified the RNAi efficiency of the candidate valid siRNA by detecting its effect on suppressing the expression of endogenous rat Mecp2 in PC12 cells. RESULTS: siRNA sequence (5'-GCUGUGAAGGAAUCUUCUA-3') targeting rat Mecp2 mRNA 918-936nt was the valid sequence to knock down rat Mecp2 expression by RNA interference. As the target sequence was located in exon 4 of rat Mecp2 mRNA, we assumed that it could suppress the expression of Mecp2alpha and Mecp2beta at the same time. And as the target sequence was located in the coding region of rat Mecp2, we assumed that it could suppress the expression of both 1.9 kb and 10 kb of rat Mecp2 transcript. CONCLUSION: This study has laid the foundation for constructing rat Mecp2 knocked-down neuronal cell model to study the gene function of Mecp2 in brain development.

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PubMed2005

[Helper-virus-free herpes simplex virus-1 vector mediated LacZ gene expression in cultured cortical neurons].

OBJECTIVE: To obtain knowledge about the helper-virus-free packaging system of HSV-1 vector and its use in cultured neurons by investigating helper-virus-free packaging of HSV-1 vector and LacZ gene expression mediated by the vector in rat cultured cortical neurons. METHODS: The cosmids with inserts of HSV-1 genome were digested by Pac I, purified and cotransfected with HSV plasmid vector DNA (with LacZ gene) into 2-2 cells. After 3 hour incubation at 37 degrees C, the media were changed into DMEM with 6% CCS. And the 2-2 cells were incubated for 72 hours at 34 degrees C. Then the virus particles were harvested. The medium with the virus particles was added to BHK cells. After 24 hour further culture, X-gal staining was performed. The virus particles were added to 3 day cultured cortical neurons. After 1, 7 and 14 day further cultures, neurons were stained by X-gal and observed under microscope. RESULTS: The BHK cells (stained blue) expressing LacZ gene could be seen after 24 hour further culture. After 1, 7 and 14 day further cultures, neurons stained blue by X-gal staining could be seen all the time in different groups. CONCLUSION: Helper-virus-free package system can produce effective virus particles from HSV-1 plasmid vector with A tyrosine TH-NF chimeric promoter and mediate stable exogenous gene expression in cultured neurons, thus providing a useful tool for gene transfer and study of gene function in the nervous system.

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