The Kidney Development and Regeneration Research Group

The Kidney Development and Regeneration Research Group headed by Professor John Bertram is a large group of energetic scientists researching the:

• molecular regulation of kidney and ureter development
• use of stem cells to repair damaged kidneys, and
• consequences of suboptimal fetal kidney development for adult kidney and cardiovascular health.

Contact john.bertram@med.monash.edu.au for further information about the projects shown below, or to discuss other opportunities.

The Lab

In 2009, the group consists of Professor Bertram, 3 Postdoctoral Research Fellows
(Dr James Armitage,  
Dr Georgina Caruana, 
Dr Luise Cullen-McEwen  
and Dr. Jinhua Li ),  
4 PhD students ( Stephen Gray, Sarah Henry, Ken Walker, Ryan Wood-Bradley), 
1  Honours student (Katrina Sorocos)
and 2 grant funded Research staff (Debbie Arena and Rebecca Douglas-Denton).

Current research projects available

Molecular regulation of kidney and ureter development

In several recent studies we have defined the gene set expressed during normal kidney and ureter development. But which of these genes is/are critical to kidney and ureter development, and what is their role? We are interested in finding the genes required to make the kidney and ureter. Such genes are not only important in fetal kidney and ureter development, but we expect they can be used to repair diseased adult kidneys and ureters.

Effects of prenatal alcohol exposure on kidney development

High levels of alcohol consumption during pregnancy lead to serious congenital abnormalities. But less is known about the effects of low to moderate alcohol consumption during pregnancy, and very little is known about the effects on the kidney? This is reflected in the wide ranging guidelines given to pregnant women across the world regarding drinking during pregnancy. This raises the questions as to whether there is a safe level of alcohol exposure? This project studies the effects of alcohol on the developing kidney using in vitro and in vivo approaches.

Effects of glucocorticoids on kidney development.

We have shown that exposure to natural and synthetic glucocorticoids during pregnancy lead to the development of a kidney with a nephron deficit. Offspring develop hypertension in later life. We are investigating the molecular mechanisms of this phenomenon, and further defining the morphological and physiological outcomes.

Effects of ultrasound radiation on kidney development.

Ultrasound during pregnancy has been used for over 40 years. Earlier studies have demonstrated that prolonged exposure to ultrasound during pregnancy can lead to fetal growth restriction and can cause apparently transient structural damage to fetal vasculature leading to haemorrhage in developing lungs and bowel. However, the long-term impacts of such adverse effects and the implications for the development of kidney and cardiovascular disease in later life have not been explored to date. Given the exponential increases in power outputs of modern ultrasound machines, and increase in use, investigations into delayed effects of repeated ultrasound examinations during pregnancy are crucial and over-due.

Exploring the molecular, physiological and morphological bases of renal developmental programming.

Increasing evidence is showing that suboptimal embryonic, fetal and/or neonatal development can result in chronic adult disease, including kidney and cardiovascular disease. However, the molecular mechanisms underlying these phenomena are almost completely unexplored. We have developed a mouse model of kidney developmental programming, whereby the mouse is born with a deficit in the number of nephrons. This project is defining the morphological and physiological characteristics of these mice, and also using gene microarray and bioinformatic approaches to define the molecular basis of these phenomena.

Rescuing nephron number in TGF β2 heterozygous mice

We and others have shown that a variety of fetal/maternal perturbations and gene defects result in a permanent nephron deficit in the kidney. Offspring often develop hypertension and kidney disease in adulthood. In a recent finding, we have shown that mice with a reduced level of the growth factor, transforming growth factor β2 (TGF-β2) have 60% more nephrons than control mice. This is the first finding of increased nephron number in a setting of altered growth factor activity. We are analysing kidney structure and function in these mice as well as their blood pressure. We are also aiming to manipulate TGF-β2 signalling to see if we can rescue nephron number in mice born with a nephron deficit.

Stem cell repair of adult kidney disease

It is generally believed by experts that the adult kidney contains a progenitor or stem cell/s. However, such a cell has not yet been identified. We are conducting a range of studies aimed at discovering stem cells in the adult kidney, with the aim of ultimately harnessing these cells for the purpose of repairing diseased kidneys. Our research is focused on understanding in detail the cellular basis of tubule and blood vessel repair in the diseased kidney, and defining the roles of kidney cells and non-kidney (eg. bone marrow) cells in these processes.

Funding

Our kidney development and regeneration research is funded by the NHMRC, the National Heart Foundation, Kidney Health Australia and Monash University.

Collaborators

Our main research collaborators are based in the Department of Physiology (Monash), Monash Immunology and Stem Cell Laboratories, the Australian Stem Cell Centre, and the University of Queensland. The group has a strong national and international reputation and is very productive, publishing in excess of 75 scientific papers in the past 5 years. See Publications

Techniques

Our studies of kidney development and regeneration utilise a wide range of molecular, physiological and morphological techniques. These include cell and tissue culture (including culture of whole embryonic mouse and rat kidneys, culture of specific subcompartments of developing kidneys, culture of specific cell lines), fluorescence-activated cell sorting (FACS), laser capture microdissection, manual microdissection, imaging (including phase, DIC, fluorescence, confocal microscopy, image analysis, stereology, time-lapse movies), whole mount and section in situ hybridisation histochemistry, RT-PCR, real time PCR, Northern and Southern blotting, gene microarrays and bioinformatics. Physiological parameters under investigation include blood pressure (tail cuff and telemetry methods), glomerular filtration rate, renal blood flow, and urinary protein.

Many of our studies utilise transgenic reporter mouse strains, or knockout mice. Hoxb7/GFP transgenic mice are an important tool in our research. These mice express GFP (Green Fluorescent Protein) in the ureteric epithelial 'tree', which we can visualise using fluorescent or confocal microscopes. Using a specially designed environmental chamber we can culture Hoxb7/GFP kidneys on a confocal microscope which enables us to image the same kidney on multiple occasions. We can then create timelapse 'movies' and study growth rates and remodelling of the ureteric tree under different culture conditions.

A Hoxb7/GFP transgenic mouse kidney at embryonic day 15

Hoxb7/GFP transgenic mice represent a powerful tool for analysing the molecular regulation of ureteric branching morphogenesis in the developing mammalian kidney.

A mouse kidney cultured for 4 days and stained with fluorescent markers. Green - calbindin (a marker of ureteric epithelium); Red -Peanut Agglutinin (a marker of glomeruli)

Phase contrast photographs of embryonic rat kidneys. (A) at the beginning of the culture; (B) after 2 days of culture; (C) after 4 days of culture.