Alberta Innovates- Health Solutions

Dr. Marli Robertson, a pediatric gastroenterologist at the University of Calgary, wants to find new therapies to help children who suffer from short-bowel syndrome (usually due to surgery as newborns) or conditions where the bowel lining becomes damaged. Her focus is a single cell layer called the epithelium which lines the inside wall and the frond-like protrusions of villi of the small intestine.

Epithelial cells, found throughout the body wherever it makes contact with the external environment, serve a variety of functions essential to normal health. In the intestines, they

• form the gateway, as well as a barrier, between the intestinal contents and the cells of the intestine
• must balance chemical messages from both these environments
• selectively bring salt, water and nutrients to the intestinal cells
• keep their structure and size relatively constant while doing so
• must maintain an acid-base equilibrium or pH balance
• proteins in cell's membranes restore pH and cell size (affected by salt transport) balance to maintain cell form as well as cell function

“The ability to maintain cell size and pH, despite changes in the external environment and in the rate of transport, is called homeostasis. It is essential for cell survival,” says Dr. Robertson.

By responding to small changes in acidity, acid-base transporters act as signals to change the cell's many functions. Dr. Robertson studies the sodium-hydrogen exchanger as “it may be involved in the signalling pathways tied into the cell's response to growth factors that tell a cell to divide or to die.” She compares these adapting intestinal cells with normal epithelial cells believing their response to growth factors has implications for infants with short-bowel syndrome.

Dr. Robertson also works with Dr. Deborah Dewey and Laura Kaminsky on a project studying how children cope with pain stemming from a condition known as functional abdominal pain. Suffering from chronic pain without an identifiable physical cause, these children receive psychological support (stress does not cause this condition). The team assesses how these children cope with pain to see if these coping strategies can help children who suffer chronic pain from other illnesses.

For more information on chronic pain, check the North American Chronic Pain Association of Canada website.