Dr. David Waisman
Neuroscience, Cardiovascular, Cancer
Clotting factors :
While Dr. David Waisman is well known for his work on the role of blood-vessel growth in the spread of cancer, he is looking more closely now at a protein in the blood that plays a pivotal role in a wide range of diseases. these include cancer, heart disease, stroke, multiple sclerosis and Alzheimer's disease.
The protein is called fibrin and it is essential to the blood-clotting process that prevents life-threatening blood loss in the event of an injury.
"Fibrin is a threadlike protein that forms at the location of an injury, creating a fibrous mesh that blocks the flow of blood," explains Dr. Waisman, a professor in the departments of Pathology and Biochemistry & Molecular Biology. "however, when the production, maintenance or breakdown and elimination of fibrin is not working properly, it can lead to disease."
In the case of cancer, cancer cells secrete enzymes that break fibrin down and allow cancer cells to break out of the tumour body into nearby blood vessels, leading to metastasis. In some infectious diseases, bacteria and viruses spread through the body in a similar manner, breaking down fibrin so they can infiltrate tissues.
An excess of fibrin can also cause problems, such as blood clots, heart attacks and strokes. In MS and Alzheimer's disease, leaks in the blood-brain barrier allow fibrin to accumulate in nervous tissue, where it damages delicate structures.
Dr. Waisman and his team examine brain and other tissues in Dalhousie's Histology Lab, using sophisticated tissue processing equipment like the Leica HistoCore PEARL being purchased with funds from the 2018 Spring Moly Appeal. In fact, Dr. Waisman is the chair of the Histology Lab Working Group and spearheaded the application to raise funds for this crucial piece of equipment.
"To clearly see the accumulation of fibrin in brain cells, for example, we need tissue samples that have been properly prepared to maintain all of the cellular structures in the exact same size and position as in the living tissue," he explains. "That's the only way we can see what is really happening and reach accurate conclusions."
Among several collaborations, Dr. Waisman is working with neuroscientist Dr. Alon Friedman to study how fibrin and other proteins wreak havoc in the brain following a breach of the blood-brain barrier.