Glomerular β-galactosidase expression following transduction with microsphere-adenoviral complexes

Glomerular β-galactosidase expression following transduction with microsphere-adenoviral complexes. The aortic injection of adenoviral-microsphere complexes is a useful technique for in vivo gene transfer (transduction) to the glomerulus. In this approach, the appearance of the foreign transprotein in the glomerulus may result from glomerular cell gene transfer and local synthesis or hepatic cell transduction followed by synthesis, secretion, and deposition in the glomerulus. We postulated that glomerular expression of the foreign transgene was the result of glomerular cell transduction. To test this question, male SD rats underwent aortic injections with adenovirus containing the LacZ expression cassette [expressing β-galactosidase (βgal)] coupled to 16 μm diameter microspheres. After 48 hours, histologic staining confirmed glomerular expression of the βgal transprotein and reverse transcription in situ polymerase chain reaction demonstrated the presence of the βgal transgene in the glomerulus. In addition, hepatic expression of the βgal transprotein was minimal and substantially less than that observed in the glomeruli. These data support the contention that adenoviral-microsphere complexes result in glomerular cell transduction with the desired transgene, followed by local transprotein synthesis. This approach may prove useful for facilitating glomerular gene transfer in the development of gene therapy for glomerulonephritis.