Aging-induced changes in microdomains of vascular smooth muscle lead to alterations in vasomotor function

Cardiovascular diseases are the primary cause of death and disability in Canada, accounting for one-third of all deaths in 2002. Age significantly increases the risk of developing cardiovascular diseases. As our elderly population increases, it is very important to improve our understanding of how and why cardiovascular diseases occur with age. Most cardiovascular diseases are caused by problems with the way our blood vessels work, especially changes in the muscle layer (made of cells called smooth muscle) that surrounds the blood vessels. The calcium level in smooth muscle is critical for proper cell function, allowing the muscles to contract and generate force. Within the cell, the way that internal compartments called organelles are arranged in relation to each other allows high concentrations of calcium to be localized to small pockets of the cell called microdomains. Microdomains are important for smooth muscle cells to function properly, because certain adjacent proteins are only activated by high concentrations of calcium. Disintegration of microdomains leads to the development of various health conditions. Harley Syyong was previously funded by MSFHR for his Master’s research training. He hypothesizes that smooth muscle cells undergo major changes in organelle arrangement as we age – making it difficult or impossible for cells to form calcium microdomains. Furthermore, proteins that generate microdomains may also be affected, including changes in where they are located or how much of the protein is made. Syyong is monitoring different blood vessels across time, identifying changes to organelles and proteins and determining how they affect blood vessel function. He hopes a better understanding of these changes could lead to ways to decrease the effects of aging on blood vessels, alleviating cardiovascular disease in the growing older population.