TRANSCRIPTIONAL ACTIVATION OF A HYBRID PROMOTER COMPOSED OF CYTOMEGALOVIRUS ENHANCER AND BETA-ACTIN BETA-GLOBIN GENE IN GLOMERULAR EPITHELIAL-CELLS IN-VIVO/

The aim of this study was to seek a promoter, transactivated selective ly in renal cells in vivo by using transgenic (tg) mouse technology. W e generated two kinds of tg mouse lines carrying a green fluorescence protein (GFP) cDNA driven either by cytomegalovirus enhancer and beta- actin/beta-globin promoter (CX-GFP) or by elongation factor 1 alpha pr omoter (EF-GFP), and investigated the expression of GFP in the kidney. Microscopic examination of the renal tissues in CX-GFP-tg mice reveal ed that GFP was expressed only in glomeruli, mainly epithelial cells, but not in tubules, arteries and interstitium. Moreover, in situ hybri dization demonstrated that GFP mRNA expression was localized in the gl omerular cells. In contrast, GFP was not delectable in the kidney in a ny of the lines of EF-GFP-tg mouse. To exclude the possible involvemen t of the GFP cDNA as an enhancer, we constructed tg mice carrying the CX promoter driving a human CD4 cDNA. It was confirmed that the expres sion patterns of human CD4 in the kidney were quite similar to those o f GFP in the kidney of CX-GFP-tg mice. These results strongly suggest that CX promoter could be transactivated in glomerular epithelial cell s in vivo.