Fat stem cells dog dodgy hips

Ben Herbert and Marc Wilkins are pioneers of proteomics science in Australia, so why are they leading research into adult stem cells? Serendipity, liposuction and a mutual veterinarian, it seems.

The two have been at the forefront of the proteomics revolution in Australia, first meeting in the early nineties at Sydney’s Macquarie University when proteomics was in its infancy.

Wilkins first coined the term ‘proteomics’, and the duo were part of a group from Macquarie that struck out into the commercial world with the biotech company Proteome Systems, which continued their academic work in developing new technologies for proteomics research and applying it to the drug discovery.

Now back in academia – Herbert is an associate professor at the University of Technology, Sydney, and is director of its Proteomics Centre of Expertise, while Wilkins is a professor of systems biology at the University of New South Wales – they are also non-executive directors Regeneus, a private biotechnology company that provides the technology for adult stem cell transplants in dogs with dodgy hips and joints.

And what brought them together for this new venture is fat, or more strictly the vast quantities of biological material to be found in adipose tissue.

At UNSW, Wilkins is working on protein-protein interactions, protein complexes and on building up a picture of protein interaction networks. In short, he is building very large datasets to try to visualise exactly how the insides of cells work.

Herbert and his team are also working on this very difficult but emerging area of science, providing their expertise in protein separations and attempting to separate proteins from protein complexes under native conditions.

They have predominantly been working in yeast, and have recently published a paper on their work. It is mammalian cells that they really want to target, however, but the main issue has been the scarcity of material.

“It was a mutual colleague who mentioned that the only place to get large amounts of human material from somebody who wasn’t dead was fat from liposuction,” Herbert says.

“We all thought that sounded like a good idea, and in our early research we found that there is a small group of people around the world who are working on fat.

“They have known for about 10 years that adult stem cells reside in reasonably high numbers in fat, so we were diverted from our original idea and started to think about what we could do with these stem cells.”

They consulted another colleague, Dr Graham Vesey, a microbiologist who has a great deal of expertise in flow cytometry and antibodies on cell surfaces. Vesey is a well-known figure in the biotechnology world, having co-founded a company called BTF that developed the wonderful BioBall, a water-soluble ball containing a precise number of bacteria that is used in microbiology for quantitative quality control.

BTF was acquired by bioMérieux in September 2007 and BioBall is now being sold into more than 30 countries.

Vesey came on board as CEO of a new company they named Regeneus, and in a serendipitous turn of fate, he and Herbert happen to get their dogs treated at the Ku-Ring-Gai Veterinary Hospital, one of the largest and best-equipped practices in Sydney.

Discussing with practice senior partners Dr Angus Ross and Dr Jamie Geddes the possibilities of using stem cells from adipose tissue to treat a number of diseases, they hit on an interesting idea: why not try it out in dogs?

That is what they are now doing. Ku-Ring-Gai Veterinary Hospital and Regeneus have now treated over 60 dogs with degenerative arthritis with autologous adult stem cell transplants, and the results have been extraordinarily good.

The vets are doing the liposuction and the transplants, while Regeneus takes care of separating the cells from the connective tissue, selecting the stem cells and purifying them ready for injection.

---PB--- Mesenchymal stem cells

Mesenchymal stem cells (MSCs) are difficult to track down as they are rather scarce, but reasonably large quantities can be extracted from fat.

In vitro, MSCs can be differentiated into chondrocytes, bone cells, neural cells and muscle cells, and have been used to treat kidney failure, another area Herbert and his team at UTS, particularly his grad student Michael Medynskyj, are pursuing.

MSCs are not pluripotent like embryonic stem cells but they are multipotent, and they work very well when differentiated down the chondrocyte line, which is what Herbert and co are pursuing in the canine project. And dogs are proving to be the perfect model, for a number of reasons.

“In the veterinary world there are a lot of animals that are euthanised for things like renal failure and for chronic arthritis, which have basically made their quality of life so poor that there are not many options for their owners,” Herbert says.

“Angus and Jamie said, why don’t we offer this as a free service to people who aren’t keen to euthanise their dog and would love to have an opportunity to try something like this? So we did, and it worked. Of course, looking in the literature we had every reason to think it would work so it’s not like this was a stab in the dark.”

Fortunately, under Australia’s veterinary act, if a veterinarian believes it is in the best interest of the animal they are treating, they are allowed to use off-label applications. That means that medicines or procedures that are not normally supposed to be used on particular animals can be if the vet thinks it would be useful.

The vast majority of dogs that the Ku-Ring-Gai vets have treated are elderly dogs with hip dysplasia and other conditions caused by osteoarthritis, and normally these dogs would not be suitable for hip replacement.

They are given anti-inflammatories and pain killers, but when their quality of life deteriorates to the point that they cannot stand up, euthanasia is the only option.

Approximately 60 dogs have been treated, and the results have been quite excellent.

“We’ve got animals who were treated 10 months ago and they are still improving,” Herbert says. “You see a very rapid increase in their mobility and their general joy of living in the first few days to the first few weeks, which is probably to do with pain and inflammation being reduced.

“Then over time, the curve begins to level and it only goes up slowly in terms of how they are being assessed by their owners and the vets, but 10 months later we have dogs where the trend is still upwards in terms of how the dog appears, its pain and its mobility.

“In the longer term it remains to be seen whether they will need a follow-up treatment, and that may be the case, especially if you haven’t addressed the underlying issues that caused the joint instability in the first place.”

---PB--- Human applications

Not surprisingly, Regeneus has received a lot of human interest in the trials, particularly after the story appeared on the ABC’s 7.30 Report last Christmas. That report also featured Hero, a young golden retriever with rheumatoid arthritis who was increasingly unable to carry out his duties as an assistant dog to a young boy with cerebral palsy.

Hero has been treated with the stem cell procedure and is doing well, although as rheumatoid is much less common in dogs than in humans, and is caused by a completely different underlying disease, it is much more complicated than osteo.

Still, rheumatoid arthritis, and Hero, are being closely watched as to the potential of stem cells as a therapy.

Human trials are obviously a lot more difficult from a regulatory perspective than animal trials, and there are approximately 11,000 patents out there relating to mesenchymal stem cell therapies, but a bonus for Regeneus is that the stem cells they are using are autologous, are not cultured or perturbed, and are reasonably straight forward.

Regeneus has a patent pending on its stem cell extraction and purification procedure, and is obviously aiming at human applications. It is a while down the road yet, but in the meantime further application areas, and human trials, are what the company is aiming at.

If it does get into human trials, Herbert himself will be putting his hand up. “I’ll certainly be in the queue, as close to the front as I can get,” he says.

“I ruptured the anterior cruciate in my left knee in the early 1990s playing hockey, and had a ligament reconstruction on that, but then I partially ruptured the grafted ligament. The orthopaedic surgeon wasn’t too pleased.”