Michael Regnier

The goal of my research is to understand the mechanisms that control contraction in both the heart and skeletal muscle. The rate at which muscles can produce force or shorten is an important factor in the control of movement. These parameters are also important in cardiac contractions where they control the amount and rate of blood pumped by the heart. At the cellular level the rates of muscle force development and shortening are determined by interactions of the proteins actin and myosin, and these interactions are fueled by the hydrolysis of ATP. This thermodynamic process of chemical energy conversion into mechanical work (chemo-mechanical transduction) is controlled by calcium binding to a group of regulatory proteins associated with actin. The mechanisms by which these proteins regulate muscle force and shortening are still poorly understood, however, due to the complex and cooperative interactions that occur between myosin, actin and thin filament regulatory proteins during contractions. There is increasing evidence of significant differences between cardiac and skeletal muscle contractile regulation, which likely results from different isoforms of thick and thin filament proteins.

Pathologies such as diabetes, hypertrophic cardiomyopathy, hypothyroidism and heart failure, as well as ischemia/reperfusion injury, involve alterations in the contractile and regulatory proteins of myocardium. Changes in protein isoforms resulting from disease or mutation often impair cardiac function during normal activation of the heart or during strenuous activity. A long-term objective of our research is to understand the detailed mechanisms of Ca2+ mediated thin filament (TF) activation and regulation of contraction in striated muscle to provide information in designing effective preventions and therapies to cardiac myopathies.

Another area of research interest for me is how exercise results in adaptations that help combat disease and aids in recovery and prevention from injuries. This area of research has the potential to dramatically reduce the cost of health care.

Neurophysiology
Exercise Physiology

Cardiac Repair