MCRI’s Kidney Development, Disease and Regeneration laboratory is headed by Professor Melissa Little, and uses stem cells to grow mini kidneys (organoids) using human cells to understand kidney diseases, find treatments, and eventually develop replacement organs.
The kidney is a complex and essential organ required for maintaining fluid balance, blood volume and electrolyte stability in the body. Chronic kidney disease, if left untreated will lead to kidney failure eventually resulting in death.
Each year, more than 4000 Australians are diagnosed with chronic kidney disease, with a 6% increase in cases per year. In children with kidney disease, around 50% is inherited, and in many instances the disease-causing mutation is unknown, significantly limiting treatment options. Current treatments for chronically diseased and failing kidneys include dialysis or transplantation. Overall, kidney disease costs $1 billion per annum in Australia. There is an urgent need to develop novel therapies for kidney disease, as currently only 1 in 4 renal failure patients will receive a transplant.
At MCRI, our researchers are world leaders in generating models of the kidney from patient stem cells. By recreating human kidney tissue from stem cells, we are now able to ‘model’ the human organ in the laboratory. As these stem cells can be made from patients, it is now possible to precisely investigate the cause of kidney disease in each specific patient. The hope is to use these mini-kidneys to better understand kidney development and diseases, to test drugs for results and toxicity to find treatments for kidney diseases, and eventually to bioengineer whole replacement kidneys for transplantation.
Rebuilding the kidney using human pluripotent stem cells
The prevalence of chronic kidney disease is continuing to rise worldwide, and with limited treatment options available and a shortage of suitable donor organs, there is a real need for new treatment options. Our laboratory has pioneered methods of using stem cells to grow mini kidneys, also known as kidney organoids in the lab. Ultimately the utility of these mini-kidney tissues will depend on how effectively they mature and replicate a normal kidney and we are currently working toward improving the structure, size and function of these organoids. Further understanding the genetic pathways involved in the formation and maturation of each cell type during kidney development will help us better replicate normal development in a dish. We anticipate this research to be revolutionary to kidney disease treatment options via two avenues: one is through patient-derived disease modelling and drug screening approaches that further our understanding of kidney diseases and lead us toward new treatment options; the second is through the regeneration of kidney tissue for transplant or the development of artificial kidneys,
Modelling kidney disease in a dish using patient-derived stem cells and drug screening
One key area of our kidney research focuses on creating stem cells from patients and recreating their kidney tissue or mini kidney organoids in our laboratories. This allows us to recreate and study their disease more closely – this method of research is called disease modelling. If we are able to determine a genetic cause for the disease through studying a patient’s tissue in the laboratory, we now have the gene editing capability and technology to correct mutations found in that patients’ genome. By comparing a patient’s genetically mutated and corrected cell lines, we are able to better understand a disease’s cause and progression, which informs our understanding of any potential preventative measures, tests for that disease, developing new treatments and hopefully cures. We are also investigating whether mini-kidneys can be used to screen for drugs that cause damage to kidney tissue, or relieve the underlying causes of kidney disease.
Understanding how nephron stem cells are maintained and characterised
The kidney is a tricky organ when it comes to regenerative treatment options. A kidney has millions of functional units within it called ‘nephrons’ which develop from kidney stem cells in utero. Once a child is born, no further nephrons can be created within the kidney, regardless of any damage or disease that may impact on their ability to function properly. In our laboratory, we have recently discovered a method of recreating these kidney stem cells, which has in turn enabled us to create mini-kidney ‘organoids’. We are continuing to learn how these stem cells can be best maintained in order to improve our development of kidney organoids for regenerative treatment options, drug screening and disease modelling applications.
Van den Berg CW, Avramut MC … Vanslambrouck JM, Koster AJ, Howden SE, Takasato M, Little MH, Rabelink TJ. (2018) Renal subcapsular transplantation of PSC derived kidney organoids induces neo-vasculogenesis and significant glomerular and tubular maturation in vivo. Stem Cell Reports. 10(3):751-765.
Forbes TA, Howden SE, Lawlor K, Phipson B, Maksimovic J, Hale L, Wilson S, Quinlan C, Ho G, Holman K, Bennetts B, Crawford J, Trnka P, Oshlack A, Patel C, Mallett A, Simons C, Little MH. (2018) Patient-iPSC-derived kidney organoids show functional validation of a ciliopathic renal phenotype and reveal underlying pathogenetic mechanisms. American Journal of Human Genetics. 102(5): 816-831.
Takasato M, Er P, Chiu H, Maier B, Baillie G, Ferguson C, Parton R, Wolvetang E, Roost MS, Chuva de Sousa Lopes SM, Little MH. (2015) Kidney organoids from human iPS cells contain multiple lineages and model human nephrogenesis. Nature. 526(7574):564-68. [Front cover].
Takasato M, Er PX, Becroft M, Vanslambrouck JM, Stanley EG, Elefanty AG, Little MH. (2014) Directing human embryonic stem cell differentiation towards a renal lineage generates a self-organizing kidney. Nature Cell Biology. 16(1):118-26. [Front cover].
Short KM, Combes AC, Lefevre J, Ju AL, Georgas KM, Lamberton T, Cairncross O, Rumballe BA, McMahon AP, Hamilton NA, Smyth IM, Little MH. (2014) Global quantification of tissue dynamics in the developing mouse kidney. Developmental Cell. 29(2): 188–202.