Proteostasis in Senescent Endothelial Cells

Do senescent primary human coronary artery endothelial cells have a diminished heat shock response and/or impaired proteostasis? Listen as Editor in Chief Irving H. Zucker (University of Nebraska Medical Center) interviews lead author Aldrin Gomes (University of California Davis) and content expert Cameron McCarthy (University of Toledo) about this novel new study by Hwang et al, which determines that estrogen did not decrease protein aggregation nor improve the heat shock response in senescent vascular endothelial cells. As the current study was performed using all female donor coronary artery endothelial cells, the authors suspect sex differences play a key role in estrogen and heat shock response. How might the regulation of anti-oxidant enzymes and the pro- anti-oxidant transcription factor Nrf-2 play a role in reducing oxidative stress and proteolysis? Does a so-called Mediterranean diet show promise in reducing levels of oxidative stress biomarkers? Listen and learn more.

 

HyunTae V. Hwang, Yun Lin, Michelle N. Rebuffatti, Darlene T. Tran, Lily Lee, Aldrin V. Gomes, Chin-Shang Li, and Anne A. Knowlton Impaired proteostasis in senescent vascular endothelial cells: a perspective on estrogen and oxidative stress in the aging vasculature Am J Physiol Heart Circ Physiol, published February 1, 2019. DOI: 10.1152/ajpheart.00318.2018

K+ Channel Isoforms Regulate Human Atrial Arrhythmogenesis

Can small changes in action potential duration have a major impact in human atrial electrophysiology? Listen as Associate Editor Mario Delmar (New York University) interviews authors Wayne Giles (University of Calgary) and Sanjiv Narayan (Stanford University) along with content expert Brian Delisle (University of Kentucky) about the new study by Ni et al. Combining mathematical modeling and clinical observations, Ni et al found that alternans could be strongly influenced by the types of potassium currents expressed in atrial myocytes, and that some potassium channel isoform switches occurring in atrial fibrillation may affect atrial physiology. The current study takes a reductionist approach to compare a single atrial control myocyte and a single myocyte in a-fib. What might the authors find if they replicate the isoform switch and study the conducted action potential in a 2-dimensional “sausage” of hundreds of myocytes? Listen and learn more.

 

Haibo Ni, Henggui Zhang, Eleonora Grandi, Sanjiv M. Narayan, and Wayne R. Giles Transient outward K+ current can strongly modulate action potential duration and initiate alternans in the human atrium Am J Physiol Heart Circ Physiol, published February 20, 2019. DOI: 10.1152/ajpheart.00251.2018