Success in research: Identifying how stem cells are involved in diabetes-related complications
Polly VandenBerg
Manager, Research Knowledge Translation
Currently, more than nine million Canadians are living with diabetes or prediabetes. Of those, an estimated one million do not even know that they have the disease. People who have diabetes are at risk for developing complications of the small and large blood vessels. Protecting these blood vessels from damage is a major priority in preventing diabetes-related complications. It is important to find ways to help prevent or treat the complications of diabetes in order to give the nine million (and counting) Canadians who are affected by diabetes a better quality of life.
Dr. Zia A. Khan, an assistant professor at the University of Western Ontario, is studying stem cells (immature cells that can develop into other cells). In particular, he is looking at vascular stem cells, which are stem cells that can create brand new blood vessels or repair injured ones. He is examining the cells that line our blood vessels, and how they work when blood vessels grow. Dr. Khan is studying these cells from both ends of the scale: he is examining how blood vessels get damaged in diabetes and do not grow back properly, and also at how blood vessels grow out of control in a type of benign (not life-threatening) blood vessel tumour in children. Dr. Khan believes that by examining vascular stem cells when they do not grow properly and when they grow out of control, he will be able to understand how these cells could work to make blood vessels grow as they should.
Dr. Khan’s most recent Canadian Diabetes Association-funded project was funded from 2009 to 2012. During the course of this project, he looked at the role of vascular stem cells in the development of diabetes-related blood vessel damage. Over the course of this funding, Dr. Khan examined how blood vessel damage occurs in diabetes by examining how different cells interact, and how different molecules affect those cells.
Vascular stem cells can develop into several types of cells, including cells that line the inner surface of blood vessels (like paint on the walls of a room), or cells that provide structural support in the blood vessels (like the wood beams holding up the walls). Researchers know that high amounts of glucose in the blood cause damage to the cells that line the blood vessels. This leads to the blood vessel damage that is a common complication of diabetes. Additionally, people with diabetes have fewer of the cells that can develop into the structural supports for the blood vessels circulating in their body.
Research has shown that when a person’s own vascular stem cells are transplanted into their arms or legs where there is blood vessel damage, this damage can be treated. Unfortunately, the vascular stem cells look very much like the stem cells that develop into blood cells, and it is very difficult to identify vascular stem cells in order to study them further for use as a therapy.
Dr. Khan began his study believing that diabetes makes cells change in a way that in turn causes the number of vascular stem cells in the body to decrease. Fewer vascular stem cells means that damage to blood vessels does not get repaired properly. Dr. Khan wanted to find out where in the process this damage happened, and if the damage could be treated in a way that would increase the number of vascular stem cells circulating in the blood. This would mean that diabetes-related blood vessel damage could be treated. In order to complete this research, Dr. Khan used his Canadian Diabetes Association funds to find vascular stem cells, separate them from other cells, and test if they could be used to treat blood vessel damage. Dr. Khan also investigated how many vascular stem cells he could find in people with diabetes, compared to people without diabetes, and if these stem cells were acting normally.
Although Dr. Khan is still analyzing the results of his research grant, his initial findings show that high blood glucose does not change how many vascular stem cells develop into other types of cells, which suggests that these cells can still mature properly. Dr. Khan’s research team further found that the cells that develop into the blood vessel lining were not affected by high blood glucose, but if the cells that develop into the structural support cells were exposed to high blood glucose, they would stop growing, stop circulating around the body, and would turn into fat cells instead of blood vessel support cells (they turn into couch potatoes instead of acting like the wood beams that hold up the walls). These new findings might help Dr. Khan explain why people with diabetes have fewer vascular stem cells than people without diabetes. Dr. Khan is now studying this relationship even further.
Dr. Khan’s Canadian Diabetes Association-funded research is giving him new insights into the causes of blood vessel damage in people with diabetes. He hopes that this research will allow him to develop safe treatments for people with blood vessel damage. Overall, Dr. Khan believes that his Association funding helped him provide new knowledge that can be used to develop treatments that will help repair the blood vessel damage in diabetes, and treatments that will stop uncontrolled blood vessel growth in the case of tumours. The Canadian Diabetes Association is proud to have been a supporter of this expert researcher and his ground-breaking research.