Gene transfer into the adult kidney for unravelling disease processes.

Insights into the pathogenesis of human disease must be based on an understanding of the molecular mechanisms that regulate the structure and function of individual organs. For this purpose, gene transfer technologies provide powerful and attractive tools. In principle, two different approaches are feasible to identify pathophysiological roles of certain genes: 'gain-of-function', and 'loss-of-function'. The former examines consequences of overexpression of an exogenous gene, and the latter investigates the outcomes of inhibition of a particular molecule via antisense, decoy, ribozyme and dominant-negative strategies. Gene transfer to specific renal structures allows evaluation of in vivo effects of certain molecules on the structure and function of each nephron segment. It would also be useful for therapeutic intervention in renal diseases through introduction of therapeutically relevant genes into affected sites. This article summarizes current experience with renal gene transfer and addresses its potential impacts on the understanding of renal function in vivo.