Dietary Calanus Oil, Energy Metabolism, and Cardiac Function

How can a minute crustacean found in the Norwegian seas help to normalize cardiac metabolism in obese subjects? Associate Editor Fabio Recchia (Temple University and Scuola Superiore Sant'Anna) interviews first author Kirsten Jansen (UiT The Arctic University of Norway) and expert Luc Bertrand (Université Catholique de Louvain) about the innovative new study by Jansen and co-authors. Using a mouse model of high fat diet-induced obesity, Jansen and collaborators showed that 8 weeks of food supplementation with a small amount (just 2%) of dietary Calanus oil, which is derived from the marine zooplankton Calanus finmarchicus, improved cardiac function after 20 minutes of global ischemia. The unique fatty acid composition of the wax esters in Calanus oil is expected to activate GPR 120 (an omega-3 fatty acid receptor) in the gut, causing secretion of GLP-1 and release of insulin from pancreatic beta-cells. What is the link between Calanus oil and a decrease in intra-abdominal fat deposition, glucose metabolism recovery in the heart, and calcium handling? Listen now.

 

Kirsten Maria Jansen, Sonia Moreno, Pablo M. Garcia-Roves PhD, and Terje S. Larsen Dietary Calanus oil recovers metabolic flexibility and rescues post-ischemic cardiac function in obese female mice Am J Physiol Heart Circ Physiol, published May 24, 2019. DOI: doi.org/10.1152/ajpheart.00191.2019

Effector CD8 T Cells Seed Atherogenic Foci

Do T cells directly contribute to the inflammatory response and progression of atherosclerosis? Guest Editor Kristine DeLeon-Pennell (Medical University of South Carolina) interviews lead author Anthony Vella (University of Connecticut Health) and content expert Shyam Bansal (The Ohio State University) about the new study by Xu et al published as part of the AJP-Heart and Circulatory Physiology Call for Papers on Adaptive Immunity in Cardiovascular Disease. By activating T cells via the 4-1BB pathway, also known as the common potent anti-tumor biologic CD137, Vella and co-authors found that the T cells were attracted to sites of inflammation. Using sophisticated T cell isolation techniques to analyze the T cells within the plaque, Vella and collaborators determined that co-stimulated T cells penetrated deep into the plaque and perpetuated inflammation. Does this study suggest that there is a dynamic cross-talk between immune cells, and that inhibiting infiltration by T cells into plaques could alter the cascade and inhibit the progression of atherosclerosis? How do auto-immune disease and sex differences fit into this picture? Listen and find out.

Maria Mei Xu, Antoine Ménoret, Sarah-Anne E. Nicholas, Sebastian Günther, Eric J. Sundberg, Beiyan Zhou, Annabelle Rodriguez, Patrick A. Murphy, and Anthony T. Vella Direct CD137 costimulation of CD8 T cells promotes retention and innate-like function within nascent atherogenic foci Am J Physiol Heart Circ Physiol, published April 12, 2019. DOI: 10.1152/ajpheart.00088.2019

Dietary Sodium, Oxidative Stress and Microvascular Function

How does dietary sodium affect cardiovascular health beyond its influence on blood pressure? In this lively podcast, Associate Editor Nisha Charkoudian (U.S. Army Research Institute of Environmental Medicine) interviews lead author David G. Edwards (University of Delaware) and R. Matthew Brothers (University of Texas at Arlington) about the innovative study by Ramick et al examining the mechanisms by which high dietary sodium may impair vascular function. The authors used 24-hour blood pressure monitoring to identify blood pressure-independent effects of a high salt diet for salt-resistant individuals, compared to salt-sensitive individuals. Using a 7-day randomized high and low salt diet protocol, as well as intradermal microdialysis, the authors built on previous work to investigate specific mechanisms of oxidative stress in the microvasculature with a high-salt diet. Was the source of reactive oxygen species superoxide? From a public health perspective, does this study suggest that we need to shift focus from sodium and blood pressure, to sodium and overall cardiovascular health? Listen and find out.

 

Meghan G. Ramick, Michael S. Brian, Evan L. Matthews, Jordan C. Patik, Douglas R. Seals, Shannon L. Lennon, William B. Farquhar, and David G. Edwards Apocynin and Tempol Ameliorate Dietary Sodium-Induced Declines in Cutaneous Microvascular Function in Salt Resistant Humans Am J Physiol Heart Circ Physiol, published May 10, 2019. DOI: 10.1152/ajpheart.00786.2018