AJP-Heart and Circulatory Physiology Podcast

Microvascular Function Following Preeclampsia

We recorded our latest episode on International Women’s Day 2021, and the topic is particularly relevant and fitting. Host Jessica Faulkner (Augusta University) interviewed authors Graeme Smith and Logan Barr (both at Queen’s University), as well as expert Junie Paula Warrington (University of Mississippi Medical Center) about a new study by Barr et al. Using laser speckle contrast imaging and iontophoresis, the authors assessed microvascular function in women five years postpartum in both normal pregnancy and preeclamptic pregnancy cohorts. The authors also characterized hypertensive pregnancies as either mild or severe preeclampsia, a novel stratification of patients which helped identify unique functional alterations in the vasculature of the severely preeclamptic women compared to the mildly preeclamptic women. Why do the authors hypothesize that nitric oxide depletion and oxidative stress in the preeclamptic pregnancies are the culprits behind the endothelial dysfunction seen in these patients? What role does body mass index (BMI) play in the postpartum cardiovascular effects of preeclampsia? Listen to find out.

 

Logan C. Barr, Jessica Pudwell, Graeme N. Smith Postpartum microvascular functional alterations following severe preeclampsia Am J Physiol Heart Circ Physiol, published January 22, 2021. DOI: 10.1152/ajpheart.00767.2020

E-cigarettes, Aldehydes and Endothelial Dysfunction

What are the cardiovascular effects of propylene glycol and vegetable glycerin (PG:VG) and saturated aldehydes used in electronic cigarettes? Guest Editor Loren Wold (The Ohio State University) interviews senior author Daniel Conklin (University of Louisville) and expert Mark Olfert (West Virginia University) about the latest study by Jin et al., which investigated the base liquid in E-cigarettes in the absence of nicotine and flavorings. Conklin and co-authors exposed male and female mice to the individual components of the E-cigarette aerosol cloud (PG:VG-derived aerosol, formaldehyde gas, acetaldehyde gas) and compared their results to filtered air. The authors found mice exposed to PG:VG and formaldehyde gas showed increased endothelial dysfunction, a key biomarker of chronic cardiovascular disease risk. The authors also found that female mice were more sensitive to each of the exposure conditions than male counterparts. Does this indicate that female mice are a sensitive and useful model for exposure to environmental inhalants? Do the authors think that heat-not-burn E-cigarettes may be an alternative to E-cigs using PG:VG base liquid? Listen as our experts discuss where we go from here.

 

Lexiao Jin, Jordan Lynch, Andre Richardson, Pawel Lorkiewicz, Shweta Srivastava, Whitney Theis, Gregg Shirk, Alexis Hand, Aruni Bhatnagar, Sanjay Srivastava, Daniel J. Conklin Electronic Cigarette Solvents, Pulmonary Irritation and Endothelial Dysfunction:Role of Acetaldehyde and Formaldehyde Am J Physiol Heart Circ Physiol, published February 5, 2021. DOI: doi.org/10.1152/ajpheart.00878.2020

Binge Drinking, Sleep and Sympathetic Activity

How well do we understand the underlying mechanisms of the cardiovascular consequences associated with binge drinking at night? Consulting Editor Nisha Charkoudian (U.S. Army Research Institute of Environmental Medicine) interviews lead author Jason Carter (Montana State University) and expert Craig Steinback (University of Alberta) about the latest work by Greenlund et al. While many researchers have investigated binge drinking in a laboratory setting, most of these studies are conducted during daytime hours. In contrast, Carter and co-authors aimed to mimic real-life alcohol consumption habits in their pragmatic study design, which interrogated the effects of binge drinking on sleep, as well as on sympathetic activity the following morning. Carter and his team found that study participants had increased cardiovascular stress, measured by increased heart rate and sympathetic activity, and decreased control of blood pressure. While the authors designed their study prior to the SARS-CoV2 pandemic, their findings are more relevant now than ever before. Listen as we touch on the future directions of this work, including exploring sex differences in alcohol consumption patterns and metabolization, and cognitive aspects of binge drinking.

 

Ian M. Greenlund, Hannah A. Cunningham, Anne L. Tikkanen, Jeremy A. Bigalke, Carl A. Smoot, John J. Durocher, and Jason R. Carter Morning sympathetic activity after evening binge alcohol consumption Am J Physiol Heart Circ Physiol, published January 15, 2021. DOI: 10.1152/ajpheart.00743.2020

Membrane Proteomic Profiling of the Heart

What are the latest technological advances for studying cell membrane proteins? Podcast host Lisandra de Castro Brás (East Carolina University) interviews lead author Tony Gramolini (University of Toronto) and expert Sarah Parker (Cedars-Sinai Medical Center) about the latest Review by Lee et al, which outlines challenges in the development of heart disease therapies related to the limited number of functional target proteins in cell surface receptors. The authors also examine potential limitations and workarounds for analyzing hydrophobic membrane proteins, discuss the importance of spatial location during sample harvesting, and review the potential of mass spectrometry tools for generation of robust and ample data. Our experts discuss a wide array of cutting-edge proteomic analysis tools, including tissue cytof, single-cell proteomics, and mass spectrometry, and give special attention to techniques for interrogating low-abundant proteins. This leads to an in-depth exchange about data reporting in research articles. What do the authors think is on the horizon for advanced interrogation of post-translational modifications and integrated AI-based analysis of the vast amounts of data produced by proteomic profiling? Listen to find out.

 

Shin-Haw Lee, Da Hye Kim, Uros Kuzmanov, Anthony O. Gramolini Membrane proteomic profiling of the heart: past, present, and future Am J Physiol Heart Circ Physiol, published January 15, 2021. DOI: doi.org/10.1152/ajpheart.00659.2020

Aerosolized Nicotine and Cardiovascular Control

What are the acute effects of inhaling nicotine through an e-cigarette on cardiovascular neural regulation? In this episode Guest Editor Loren Wold (The Ohio State University) interviews lead author William Cooke (Michigan Technological University) and expert Ted Wagener (The Ohio State University) about the latest research by Gonzalez and Cooke on this timely topic. As more and more studies show that e-cigarettes do carry their own distinct health risks, Gonzalez and Cooke recruited naïve e-cigarette users, otherwise known as “never smokers,” for their e-cigarette study. The authors observed an acute increase in arterial pressure in study participants, which was associated with a blunting of peripheral sympathetic activity. Why is this important? The authors believe that there could be long term effects on the heart, including increases of heart rate and blood pressure, which could lead to pre-hypertension or chronic hypertension for non-smokers who opt to use electronic cigarette devices. Our experts unpack the implications of this unique study, the potential for researchers to separate effects of inhaled nicotine from effects of inhaled combustible tobacco toxicants, and what new federal guidelines may be forthcoming from the Food and Drug Administration (FDA) for e-cigarette devices in the coming year. Listen now to find out more.

 

Joshua Eric Gonzalez and William Harold Cooke Acute effects of electronic cigarettes on arterial pressure and peripheral sympathetic activity in young non-smokers  Am J Physiol Heart Circ Physiol, published November 8, 2020. DOI: doi.org/10.1152/ajpheart.00448.2020

Sleep Deprivation and Endothelial Function

Sleep disorders, such as insomnia, sleep apnea and restless leg syndrome, have acute and chronic negative cardiovascular impacts. Why is so little known about the cellular and molecular mechanisms regulating cardiovascular events in sleep disorders? In this podcast Editor-in-Chief Dr. Irving H. Zucker interviews lead author Dr. Maureen MacDonald (McMaster University) and expert Karyn Esser (University of Florida) about an insightful new Review article by Cherubini et al. MacDonald and co-authors became interested in the affect sleep has on endothelial function while conducting their own exercise physiology studies. Reviewing the literature, Cherubini et al. found that most studies do not control for sleep, yet sleep deprivation – whether acute or chronic, partial or total – can have negative effects on endothelial function in humans. The literature also shows similar results in animal and cell culture models. Because clock mechanisms exist in every human cell type, the understanding of links between so-called “clock genes” and disease progression is an emerging field. How does this relate to the development of atherosclerotic plaques, and the potential for exercise as a therapeutic strategy to combat the negative impact of disordered sleep? Listen now.

 

Joshua M. Cherubini, Jem L. Cheng, Jennifer S Williams, Maureen J. MacDonald Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives  Am J Physiol Heart Circ Physiol, published October 16, 2020. DOI: doi.org/10.1152/ajpheart.00607.2020

Behind the Bench Episode7

Why should medical school students invest their time in basic science research? That’s our theme for this episode of Behind the Bench from AJP-Heart and Circ. Hosts Lisandra de Castro Brás (East Carolina University) and Jonathan Kirk (Loyola University Chicago) interview Dhandevi Persand and Nicole Maddie, both students at the New York Institute of Technology College of Osteopathic Medicine. Dhandevi and Nicole won the FASEB Dream Award to attend the APS Professional Skills Training Course on Writing and Reviewing for Scientific Journals, and they have co-authored a New Investigator Editorial detailing their experiences. More importantly, Dhandevi and Nicole are using their platform as Women in Stem to promote the importance of research for clinical trainees. As students in the NYIT Doctor of Osteopathic Medicine (D.O.) program, Nicole and Dhandevi focus on how structure affects function. The translational research projects they have both worked on have cemented their feelings that research is critically important for medical students and clinicians. Did you know that D.O. students must complete 200 additional hours of coursework, compared to M.D. students, in order to learn osteopathic manipulative medicine? Listen for a refreshingly open conversation about time management and reaching for “stretch goals” which turn out to be surprisingly attainable.

 

Dhandevi Persand and Nicole Maddie New investigator editorial: the osteopathic medical student perspective on research Am J Physiol Heart Circ Physiol, published December 2, 2020. DOI: doi.org/10.1152/ajpheart.00813.2020

Role of Estrogen Receptor Alpha in Right Ventricular Remodeling

Does the loss of functional estrogen receptor alpha (ERα) remove female protection from adverse remodeling? We know that right ventricular function is preserved in women with pulmonary arterial hypertension compared to men. While ERα has been identified as a likely mediator of cardioprotection in the right ventricle, the exact role of ERα in preserving right ventricular function and remodeling in pressure overload is not well understood. In this episode Guest Editor Kristine DeLeon-Pennell (Medical University of South Carolina) interviews lead author Naomi Chesler (University of California Irvine) and expert Jessica Faulkner (Augusta University) about a new study by Cheng et al that utilized a sex-independent pulmonary arterial banding model in both female and male ERα mutant rats to investigate sex-dependent differences in right ventricular response to pressure overload. In females, ERα is protective against right ventricular pulmonary vascular uncoupling, diastolic dysfunction, and fibrosis in response to pressure overload. However, the authors did not observe the same effects in males. Given that only the ERα mutant females showed a dramatic fibrotic response, were the authors surprised by what their RNA sequencing analysis revealed? Listen and find out.

 

Tik-Chee Cheng, Jennifer L Philip, Diana Marcela Tabima, Santosh Kumari, Bakhtiyor Yakubov, Andrea L Frump, Timothy A. Hacker, Alessandro Bellofiore, Rongbo Li, Xin Sun, Kara N. Goss, Tim Lahm, Naomi Chesler Estrogen Receptor Alpha Prevents Right Ventricular Diastolic Dysfunction and Fibrosis in Female Rats  Am J Physiol Heart Circ Physiol, published October 16, 2020. DOI: doi.org/10.1152/ ajpheart.00247.2020

Formaldehyde Exposure Decreases Vascular Function

What are the short-term vascular consequences of formaldehyde exposure in healthy female adults? In our latest podcast episode, Guest Editor Matthew Gorr (The Ohio State University) interviews lead author Stephen Ratchford (Appalachian State University) and expert Thiago Bruder (University of Pittsburgh) about the recent work by Augenreich et al, which was published as part of the AJP-Heart and Circulatory Physiology Call for Papers on Environmental Inhalants and Cardiovascular Disease. Utilizing a natural exposure model that measured via ultrasound the vascular response of students exposed to formaldehyde during their cadaver dissection laboratory coursework, Ratchford and co-authors found significantly decreased flow mediated dilation in the brachial artery, yet no changes in microvascular function. Ratchford and colleagues determined that only one short-term exposure to formaldehyde can have detrimental effects on vascular health. What is the significance of these finding for people exposed to formaldehyde for longer periods of time, such as instructors in cadaver dissection courses? Formaldehyde is a common preservative used in many industries, such as the cosmetic, lumber and construction industries. What are the implications related to occupational and environmental safety standards? Listen now.

 

Marc Andrew Augenreich, Jonathon Lee Stickford, Nina Stute, Laurel Kaitlyn Koontz, Janet M. Cope, Cynthia Bennett, Stephen M. Ratchford Vascular Dysfunction and Oxidative Stress Caused by Acute Formaldehyde Exposure in Female Adults  Am J Physiol Heart Circ Physiol, published October 16, 2020. DOI: doi.org/10.1152/ ajpheart.00605.2020

Post-infarction Cardiac Rupture

Why is it important to have clear diagnostic criteria to use when assessing cardiac rupture in the mouse model of permanent occlusion myocardial infarction? Listen as Deputy Editor Merry L. Lindsey (University of Nebraska Medical Center) interviews lead author Nikolaos Frangogiannis (Albert Einstein College of Medicine) and expert Kristine DeLeon-Pennell (Medical University of South Carolina) about the new study by Hanna et al which compared results from their in-depth histopathological examination with visual inspection of cardiac rupture. Frangogiannis and co-authors found that identifying the rupture site had high specificity but low sensitivity, with a low rate of false positives. Conversely, identifying hemothorax had high sensitivity yet low specificity. Hanna et al. observed key sex differences in their non-reperfusion mouse model of MI. In addition, differences in macrophages and fibroblasts in mice of both sexes which died of cardiac rupture indicated that a perturbed balance of inflammatory mediators may be a factor in the pathogenesis of cardiac rupture. What is the key take-away? When evaluating the cause of death in infarcted mice, look for the rupture site. Listen now.

 

Anis Hanna, Arti V Shinde, and Nikolaos G. Frangogiannis Validation of diagnostic criteria and histopathological characterization of cardiac rupture in the mouse model of non-reperfused myocardial infarction Am J Physiol Heart Circ Physiol, published October 15, 2020. DOI: doi.org/10.1152/ ajpheart.00318.2020