Objective To investigate the role of Ca 2+ signaling in the overexpression of detrusor smooth muscle cell connexin 43 by cyclic stretch in vitro. Methods The detrusor smooth muscle cells (DSMC) grown on collagen-coated silicone membranes were subjected to cyclic stretch-relaxation. The Cx43 mRNA in DSMC were detected with RT-PCR, and the concentration of intracellular free Ca 2+ in DSMC was measured by confocal microscopy in conjunction with the calcium indicator, Fura-3 (Molecular Probes). Results The overexpression of Cx43 mRNA induced by cyclic stretch was significantly inhibited by EGTA.The increase of intracellular free Ca 2+ induced by stretch was also inhibited completely by EGTA, 61.95% by GdCl3, 29.98% by Nifedipine, 87.98% by Ryanodine and Thapsigargin. Conclusion The stretch-induced Ca 2+ entry, via the Ca 2+-induced Ca 2+ release mechanism, may play an important role in DSMC connexin 43 overexpression induced by cyclic stretch.

OBJECTIVETo construct a universal, highly attenuated orf virus expression vector for exogenous genes using green fluorescent protein (GFP) as the reporter gene.

METHODSThe flanking regions of the ORFV132 of orf virus DNA were amplified by PCR to construct the shuttle plasmid pSPV-132LF-EGFP-132RF. The shuttle plasmid was transfected into OFTu cells and GFP was incorporated into orf virus IA82Delta 121 by homologous recombination. The recombinant IA82Delta121-V was selected by green fluorescent signal. The deletion gene was identified by PCR and sequencing. The effects of ORFV132 knockout were evaluated by virus titration and by observing the proliferation of the infected vascular endothelial cells in vitro.

RESULTSThe recombinant orf virus IA82Delta121-V was obtained successfully and quickly, and the deletion of ORFV132 did not affect the replication of the virus in vitro but reduced its virulence.

CONCLUSIONGreen fluorescent protein is a selectable marker for rapid, convenient and stable selection of the recombinant viruses. Highly attenuated recombinant orf virus IA82Delta121-V can serve as a new expression vector for exogenous genes.

Cells, Cultured ; Endothelial Cells ; metabolism ; Gene Deletion ; Genes, Reporter ; Genetic Vectors ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; Orf virus ; Plasmids ; Transfection