Mark Gillies, MD, PhD

University of Sydney, Save Sight Institute

Dr. Gillies studies Müller glia, particularly in the context of Macular Telangiectasia type 2. He has been focused on studying MacTel, and those affected by it, for more than ten years. The Gillies laboratory studies how the loss of Müller cells that occurs in MacTel affects the retina. Müller cells provide energy for photoreceptors and other retinal neurons. They are responsible for a significant amount of glucose metabolism and glycogen storage in the retina.

Dr. Gillies’ group studies Müller cells in a number of different laboratory models. In a mouse model in which Müller cells are selectively ablated, his group sees vascular leak and deep retinal neovascularization, similar to what is seen in MacTel patient eyes. Using this model, they can study the retina’s response to Müller cell loss. They have also used this model to test therapies for photoreceptor degeneration and retinal vascular leak, such as ciliary neurotrophic factor and glucocorticoids.

The Gillies Laboratory has generated transgenic mice to manipulate gene expression in Müller cells. Researchers in his group are changing the expression of genes critical for glucose metabolism to assess how the process of glucose metabolism in Muller cells affects photoreceptor function.

Based on observations from patient samples, people with MacTel consistently lose Müller cells in their central retina. Dr. Gillies and his team trying to understand what makes Müller cells in the central retina unique, and what makes them susceptible to death. To do this, they are isolating Muller cells from central and peripheral retinas. They have observed that Müller cells isolated from different regions of the retina look different under the microscope. The two different populations are also expressing different groups of genes, based on RNA transcriptome profiles. Further studies on Müller cells isolated from these two regions will help us understand why Müller cells are vulnerable in MacTel.