At UHN, we strive to deliver Compassionate Care & Caring. Learn more about the services and supports that are available to you throughout your journey.
Our UHN programs and services are among the most advanced in the world. We have grouped our physicians,
staff, services and resources into 10 medical programs to meet the needs of our patients and help us make
the most of our resources.
At the heart of everything we do at UHN are our Healthcare Professionals. Refer a patient to one of our 12 medical programs. Learn more about the resources and opportunities available for professional growth.
University Health Network has grown to be one of the largest research and teaching hospital networks in Canada - pioneers in improving the lives of patients. Our long history of health professions education at Toronto General, Toronto Western, Princess Margaret and Toronto Rehab hospitals has consistently advanced the science of education.
University Health Network is a health care and medical research organization in
Toronto, Ontario, Canada. The scope of research and complexity of cases at UHN has made us a national and international
source for discovery, education and patient care.
Being touched by illness affects us in different ways. Many people want to give back to the community
and help others. At UHN, we welcome your contribution and offer different ways you can help so you can find one that suits you.
The Newsroom is the source for media looking for information about UHN or trying to connect with one
of our experts for an interview. It's also the place to find UHN media policies and catch up on our news stories, videos, media releases,
podcasts and more.
Imagine that you've been diagnosed with a debilitating eye disease. Your vision suddenly decreases, and you can no longer clearly see your loved ones or the things that matter most to you. It can be a frightening experience.
This irreversible loss of vision, which is a symptom of eye diseases such as glaucoma, occurs when the neurons (nerve cells) that control sight are destroyed.
While researchers still do not know the exact mechanism by which this occurs, there is evidence to suggest that the accumulation of toxic reactive oxygen species is involved. These toxic compounds damage light-sensitive neurons through a process called oxidative stress.
Luckily, the body has specialized cells (astrocytes) that help produce a powerful antioxidant, known as glutathione (GSH), that neutralizes the damaging effects of the reactive oxygen species.
Dr. Jeremy Sivak, Senior Scientist at Krembil Research Institute, has been searching for ways to promote the production of GSH in order to halt, prevent, or reverse vision loss in patients with eye disease.
His team recently discovered that a protein called adenosine monophosphate-activated kinase (AMPK) increases the production of GSH in astrocytes by activating another key protein known as PGC-1 alpha.
The researchers also demonstrated—using an experimental model of eye disease—that therapeutic compounds mimicking AMPK, increase GSH levels while reducing the death of neurons in the eye.
"Activating PGC-1 alpha represents a novel strategy for enhancing protective astrocyte activity in the eye," explains Dr. Sivak.
"It is an exciting discovery that could not only be applied to eye diseases such as glaucoma, but also other degenerative diseases—such as Alzheimer's disease—where neurons are damaged by oxidative stress."
This work was supported by the Canadian Institutes of Health Research, the Glaucoma Research Society of Canada, the Natural Sciences and Engineering Research Council of Canada and the Toronto General & Western Hospital Foundation. J. Sivak is the Toronto General & Western Hospital Foundation Glaucoma Research Chair.