Investigation of a new nutraceutical for treatment of Barth Syndrome
Robin E. Duncan, PhD, Associate Professor, University of Waterloo, Waterloo, ON, Canada
Award - $41,580 over 2-year period
While working on the function of endogenous lipid signaling molecules in cardiolipin synthesis, we have discovered a potential new treatment for Barth Syndrome. In preliminary studies, we added a nutraceutical compound (Compound X) that is chemically related to a class of endogenous signaling lipids to B-lymphoblasts that we grow in flasks. These B-lymphoblasts come from five different child donors who have Barth Syndrome with neutropenia. As controls, we grew these Barth B-lymphoblast cells without Compound X, and we also grew flasks of B-lymphoblasts from 5 healthy age- and sex-matched control donors. On day 0, we started all flasks off with ~1 million cells. After 4 days, there were on average just over 5 million cells in flasks containing healthy control B-lymphoblasts, regardless of whether they were treated or untreated with Compound X, which didn’t seem to affect the growth of healthy cells.
In flasks containing B-lymphoblasts from Barth’s donors that were not treated with Compound X, there were only 3.7 million cells, on average (about 1.5 million less than in the flasks of healthy cells), which was a significant difference. However, when B-lymphoblasts from donors with Barth Syndrome were grown with Compound X, these same cells increased in number to almost 5 million cells on day 4, much like the healthy controls did. We looked at some of these cells using electron microscopy and found that mitochondria in Barth B-lymphoblasts treated with Compound X look better than mitochondria in untreated Barth B-lymphoblasts. Notably, the level of Compound X that we used reflects a dose that can be achieved pharmacologically. These findings are important since they suggest that Compound X may be a promising new treatment for Barth Syndrome. Compound X is widely available as a nutraceutical, has exceedingly low toxicity, and is also sold as a pharmaceutical-grade preparation that is an FDA-approved treatment for other childhood syndromes, so there are low barriers in translation to clinical practice. However, before Compound X can be recommended, it is important that we better understand how it functions. It is also critical that we test Compound X in an animal model of Barth Syndrome.
In this project, we propose experiments to study how Compound X increases Barth B-lymphoblast cells numbers by investigating if it can improve cell proliferation or decrease cell death through various pathways. Furthermore, we propose to study Barth donor B-lymphoblasts to determine what effects Compound X is having on the health, number, and function of mitochondria, relative to healthy control B-lymphoblasts. To determine if Compound X is safe and effective for chronic administration in a mouse model of Barth Syndrome, we propose testing two different levels of Compound X given orally, and two additional levels given by intravenous infusion, daily for 2 weeks. We will monitor respiratory metabolism over 24-hours, and test ability to exercise using a highly precise comprehensive animal monitoring system. We will also test effects on food and water intake, and body and organ mass, and will measure the accumulation of Compound X in a variety of tissues. In more detailed molecular studies, we will determine if Compound X can improve the appearance, composition, and function of mitochondria in cardiac tissue, skeletal muscle, and white blood cells from Tafazzin-deficient mice treated with Compound X, to see if has potential benefit in multiple organ systems affected by Barth Syndrome. Results from this work are expected to rapidly inform direction for a potential subsequent pharmacokinetic study and clinical trial.