Dr. Sébastien Gauvrit: Fishing for Answers in Vascular Development

Sébastien Gauvrit (PhD) was only ten when his family let him have his first tank of guppies. Within weeks, he was hooked. "I actually had to understand genetics directly by mixing these different fish together to get the colour or fin shape I was interested in," said the vascular biologist and genetic modelling pioneer. From his home in France, to post-doctoral work pioneering new models for vascular disease in Germany, to his current position as an assistant professor of Anatomy, Physiology and Pharmacology at the University of Saskatchewan's College of Medicine —  tropical fish tanks remain a constant in Gauvrit's life.   This year, two grants from the National Sciences and Engineering Research Council of Canada (NSERC) totalling $340,000 mean Dr. Gauvrit will expand the University of Saskatchewan's zebrafish aquariums — and refine his laboratory's modelling work and research on vascular development.   Zebrafish are transparent in their first hours and days, which allows scientists to watch them forming vascular cells in real time.   "Most genes that trigger vascular disease in humans are present in zebrafish," Gauvrit said, noting they share 70 per cent of of their genes with humans.   Using both fish and rodent models, Gauvrit will do a deeper analysis of the transcription factor HHEX [Hematopoietically Expressed Homeobox], because of its cascading effect on the cells that eventually determine lymphatic health.   "If you understand how this gene regulates others, we can identify new genes involved in lymphatic disease, and understand a bit more the process behind all these events," Gauvrit said. He's also looking at VEGF-A [vascular endothelial growth factor], a gene implicated in vascular diseases, including age-related macular degeneration [AMD]. Right now, patients with blurred vision and an overgrowth of blood vessels are treated with multiple injections to the eye, with the hope of limiting damage. "A high proportion of patients develop resistance against this therapy, which is a big issue," Gauvrit said. "It's also very costly."   Mice die quickly without VEGF-A, but zebrafish without it survive — even thrive. Gauvrit wants to know what processes help zebrafish compensate, and where mammalian cells diverge. Gauvrit said the broader implications of vascular research will have ripple effects in treating lymphedema, strokes, and age-related macular degeneration. "We still discover new things," Gauvrit said. "Just by serendipity and by randomness, sometimes you can find a bit greater science than when you have a very specific question."