SIRT3 and cardiac mitochondria

Post-translational modification through acetylation by the NAD+-dependent deacetylase sirtuin-3, or SIRT3, has recently emerged as a key player in regulating mitochondrial function. What is SIRT3 doing in cardiac mitochondria? How does it impact cardiac physiology and pathophysiology? Listen as Editor in Chief William Stanley and Associate Editor Junichi Sadoshima talk with the author Michael Sack (National Heart, Lung and Blood Institute, NIH) about his just-published Review article which tackles these very questions.

Michael N. Sack. Emerging characterization of the role of SIRT3 mediated mitochondrial protein deacetylation in the heart. Am J Physiol Heart Circ Physiol, published ahead of print October 7, 2011, doi:10.1152/ajpheart.00199.2011.


Electrophysiology of hiPSC-derived cardiomyocytes

The discovery of induced pluripotent stem (iPS) cells has allowed researchers to generate human cardiomyocytes from patients. Why is this important? Human iPS cells are useful for studying normal and diseased human cardiomyocytes and for discovering new drug therapies to treat cardiovascular disease. Until now, methods for generating cardiomyocytes from human iPS or ES cells were inconsistent and often unreliable. The recent article by Ma et al presents a new method to obtain a large quantity of cultured cardiac myocytes using embryoid body formation and blasticidin selection techniques resulting in more than 98% purity from human iPS cell lines. Associate Editor Junichi Sadoshima talks with authors Craig January (University of Wisconsin – Madison) and Brad Swanson (Cellular Dynamics International), along with leading expert Diego Fraidenraich (University of Medicine and Dentistry, New Jersey), about this groundbreaking research and its many potential applications.

Junyi Ma, Liang Guo, Steve J Fiene, Blake D Anson, James A Thomson, Timothy J. Kamp, Kyle L Kolaja, Bradley J Swanson, and Craig T. January. High Purity Human Induced Pluripotent Stem Cell (hiPSC) Derived Cardiomyocytes: Electrophysiological Properties of Action Potentials and Ionic Currents. Am J Physiol Heart Circ Physiol, published ahead of print September 2, 2011, doi:10.1152/ajpheart.00694.2011.


Carotid baroreflex responsiveness is impaired in normotensive African American men

It almost goes without saying that human beings are genetically diverse and that diseases develop differently, and at different rates, across various racial groups in the human population. Case in point: African Americans are predisposed to developing far deadlier forms of hypertension earlier in life than other racial group counterparts. Associate Editor Irving Zucker talks with lead author David Keller (University of Texas Arlington) and expert Peter Raven (University of North Texas Health Science Center) about the work of Holwerda et al, which studied the possibility of the baroreflex contributing to the development of hypertension in African American males.

Seth W. Holwerda, Diana Fulton, Wendy L. Eubank, and David M. Keller. Carotid Baroreflex Responsiveness is Impaired in Normotensive African American Men. Am J Physiol Heart Circ Physiol, October 2011 301:H1639-H1645; published ahead of print August 12, 2011, doi:10.1152/ajpheart.00604.2011.