Molecular Mechanisms Linking Proteinuria And Sodium Retention
Funder
National Health and Medical Research Council
Funding Amount
$211,527.00
Summary
The clinical association between protein loss in the urine and retention of salt, resulting in high blood pressure and progressive decline in kidney function, is well known. Under normal conditions, the kidneys filter 180 litres of water and reabsorb 1.7 kg of salt per day, a function which is principally performed by the kidney tubules in the kidney. Similarly the kidney tubule cells reabsorb and break down up to 3 grams of albumin per day. In the past, it has been considered that excessive pro ....The clinical association between protein loss in the urine and retention of salt, resulting in high blood pressure and progressive decline in kidney function, is well known. Under normal conditions, the kidneys filter 180 litres of water and reabsorb 1.7 kg of salt per day, a function which is principally performed by the kidney tubules in the kidney. Similarly the kidney tubule cells reabsorb and break down up to 3 grams of albumin per day. In the past, it has been considered that excessive protein loss in the urine is primarily due to problems in the filtering units of the kidneys, rather than due to abnormalities in the reabsorption of protein in the kidney tubules. However, we consider that common abnormalities in the processes within the kidney tubules that regulate both the reabsorption of salt and the excretion of acid may result in concomitant high blood pressure and increased protein loss in the kidney. Thus the overall aim of the project is to investigate the interrelationship between protein reabsorption and catabolism and Na+ reabsorption in the human kidney tubule. The project uses the combined methods of cultured human kidney tubules, biochemical and molecular biology techniques which are unavailable in other laboratories in Australia (and internationally). This project will comprehensively characterise the mechanisms of protein uptake and salt reabsorption in human kidney tubule cells when exposed to both normal and high concentrations of protein. The exact nature of the interaction of protein uptake with salt reabsorption and hence high blood pressure will be determined. As both hypertension and persistent proteinuria are the most important predictors of tubulointerstitial pathology and progressive decline in renal function in almost all renal disease, the understanding of the precise interaction between these two factors is essential in the design of renoprotective therapies.Read moreRead less
MODIFICATION OF TUBULE CELL CYTOKINES REGULATING INTERSTITIAL INFLAMMATION IN CHRONIC PROTEINURIC RENAL DISEASE
Funder
National Health and Medical Research Council
Funding Amount
$294,121.00
Summary
Current treatments for chronic kidney disease are ineffective. As a consequence, kidney failure progresses to the stage where patients require dialysis or transplantation to remain alive. Every year 1500 Australians commence dialysis for this reason, and many more die of kidney failure or its complications. One of the major reasons for progression of kidney failure is that kidney cells produce a complex network of inflammatory mediators (cytokines) which attract inflammatory cells into the suppo ....Current treatments for chronic kidney disease are ineffective. As a consequence, kidney failure progresses to the stage where patients require dialysis or transplantation to remain alive. Every year 1500 Australians commence dialysis for this reason, and many more die of kidney failure or its complications. One of the major reasons for progression of kidney failure is that kidney cells produce a complex network of inflammatory mediators (cytokines) which attract inflammatory cells into the supporting tissue of the kidney (the interstitium). Recently, drugs that inhibit these cytokines have been used in animal models of chronic kidney disease. Such treatment regimens have been at most only partially effective because they have been directed against only one cytokine, and because they have ignored the fact that the profile of cytokines varies with stage of disease. This project will use a rodent model (Adriamycin nephrosis) of human chronic kidney disease to define strategies for preventing interstitial inflammation using anti-cytokine therapy. Our laboratory has identified three cytokines which appear to play a pivotal role in the development of interstitial inflammation in Adriamycin nephrosis, and shown that their production varies with time. Knowledge of the time-dependent interactions among and regulation of these cytokines will be used to define optimal delivery of therapy directed against all three cytokines. As anti-cytokine therapy is already being trialled in other types of (non-kidney) disease in humans, the success of such a therapeutic approach to treating progressive kidney disease in this animal model will have important and immediate implications for the treatment of chronic kidney disease in humans.Read moreRead less