Group Bonny
Olivier Bonny, MA
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Olivier Bonny is a physician-scientist who earned his MD at the University of Lausanne, Switzerland and a PhD from the MD-PhD program of the Swiss Academy of Medical Sciences. His PhD thesis was led by Prof. Bernard C. Rossier and was aimed at understanding the functional relevance of mutants of the epithelial sodium channel (ENaC). He subsequently completed a post-doctoral fellowship with Prof. Orson W. Moe at the University of Texas, Southwestern Medical Center in Dallas on renal calcium reabsorption. He joined the Department of Pharmacology and Toxicology in December 2007 where he has been leading his own research group since. In parallel, Dr Bonny completed a clinical training as a nephrologist at the University Hospital Bern with Prof. Felix J. Frey and hold the Swiss board certifications in Internal Medicine (FMH). He is attending at the Division of Nephrology of the University Hospital of Lausanne. Keywords: Calcium, kidney, sodium-calcium exchanger, renal physiology, urolithiasis |
The maintenance of extracellular calcium concentration is of utmost importance for many vital functions of the body, such as blood coagulation, bone mineralization, nerve excitability or enzyme activity. Moreover, calcium regulates numerous intracellular processes by acting as second messenger. Thus, several organ systems together with a complex array of hormonal controls contribute to calcium homeostasis and to keeping calcium plasma levels tightly regulated. In particular, calcium reabsorption by the kidney is a key component of this process. In the distal convoluted and the connecting tubules, calcium is reabsorbed transcellularly under the control of PTH and vitamin D in a three-step process. From the urinary lumen, calcium enters the cell through the apical calcium channels, TRPV5 and TRPV6, is buffered by the calbindin system in the cytoplasm and is extruded into the interstitial compartment by two different basolateral transporters, the sodium/calcium exchanger (NCX1) and the calcium ATPase (PMCA) (figure 1).
How renal calcium reabsorption is regulated and what is the relative importance of the various components involved in calcium reabsorption in the kidney is not yet fully understood. Finding the appropriate tools and using them for the resolution of this issue are the ultimate goals of the research of the laboratory.
Calcium reabsorption in the distal convoluted and connecting tubule of the nephron.
