Isolation of renin-producing human cells by transfection with three simian virus 40 mutants

A human juxtaglomerular cell (JGC) tumor was used for the immortalization of renin-secreting cells. The transfection of primary JGC with three different simian virus 40 (SV40) mutants resulted in the continuous production of renin-secreting cells. The most efficient renin-producing cells (producing about 400 pg of renin per 24 hr per ml of culture medium) were those transfected with the PAS SV40 mutant. The renin production was stable and the cell cultures have been maintained for greater than 1 year. Two types of cells were cultured together and could not be separated: round and birefringent cells, which exhibited features of mast cells, and elongated cells containing myofilaments and secretory granules. Immunocytochemical staining showed the presence of renin in this latter cell type. The renin produced by the transfected cells was not stored within the cells but was released rapidly into the medium. More than 95% of the renin produced was prorenin, which, after activation, had characteristics similar to those of pure human standard renin as to its enzymatic, immunologic, and biochemical properties, except that it was less glycosylated. These stable JGC tumoral cell lines provide a unique system for studying human renin biosynthesis and its regulation in vitro.