[Frontiers in Bioscience E2, 1227-1233 June 1, 2010]

Recent advances in tissue (pro)renin imaging

Agnes Prokai1,2, Janos Peti-Peterdi 2

1Hungarian Academy of Sciences, Research Laboratory for Pediatrics and Nephrology, and 1st Dept. of Pediatrics, Semmelweis University, Budapest, Hungary, 1089, 2Departments of Physiology and Biophysics and Medicine, Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, California, USA, 90033

TABLE OF CONTENTS

1. Abstract
2. The multiphoton imaging approach
3. Intravital imaging of the tissue renin-angiotensin system (RAS)
4. (Pro)renin in the distal nephron
5. Effects of the handle region peptide (HRP)
6. Summary and conclusion
7. Acknowledgements
8. References

1. ABSTRACT

Due to its pivotal role in blood pressure control and renal pathologies there is renewed interest in renin and its precursor prorenin. Also, the newly discovered (pro)renin receptor is a new element of the ever broadening renin-angiotensin system (RAS). The complexity of RAS including the recently recognized collecting duct site of (pro)renin (a term denoting both renin and prorenin) synthesis requires the use of advanced research techniques such as multiphoton fluorescence microscopy. With the help of this technology we have pioneered an imaging approach to directly visualize (pro)renin content, release and tissue activity in the living kidney. The use of this technology is reviewed here and exemplified by the direct visualization of (pro)renin activity in the collecting duct. New pharmacological tools, the renin inhibitor aliskiren and the handle region peptide (decoy peptide) was used to further characterize