Browsing by Author "Lefer, David J."

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    Alcohol-induced gut microbial reorganization and associated overproduction of phenylacetylglutamine promotes cardiovascular disease
    (Springer Nature, 2024-12-30) Li, Zhen; Gu, Min; Zaparte, Aline; Fu, Xiaoming; Mahen, Kala; Mrdjen, Marko; Li, Xinmin S.; Yang, Zhihong; Ma, Jing; Thoudam, Themis; Chandler, Kristina; Hesler, Maggie; Heathers, Laura; Gorse, Kiersten; Van, Thanh Trung; Wong, David; Gibson, Aaron M.; Wang, Zeneng; Taylor, Christopher M.; Quijada, Pearl; Makarewich, Catherine A.; Hazen, Stanley L.; Liangpunsakul, Suthat; Brown, J. Mark; Lefer, David J.; Welsh, David A.; Sharp, Thomas E., III; Medicine, School of Medicine
    The mechanism(s) underlying gut microbial metabolite (GMM) contribution towards alcohol-mediated cardiovascular disease (CVD) is unknown. Herein we observe elevation in circulating phenylacetylglutamine (PAGln), a known CVD-associated GMM, in individuals living with alcohol use disorder. In a male murine binge-on-chronic alcohol model, we confirm gut microbial reorganization, elevation in PAGln levels, and the presence of cardiovascular pathophysiology. Fecal microbiota transplantation from pair-/alcohol-fed mice into naïve male mice demonstrates the transmissibility of PAGln production and the CVD phenotype. Independent of alcohol exposure, pharmacological-mediated increases in PAGln elicits direct cardiac and vascular dysfunction. PAGln induced hypercontractility and altered calcium cycling in isolated cardiomyocytes providing evidence of improper relaxation which corresponds to elevated filling pressures observed in vivo. Furthermore, PAGln directly induces vascular endothelial cell activation through induction of oxidative stress leading to endothelial cell dysfunction. We thus reveal that the alcohol-induced microbial reorganization and resultant GMM elevation, specifically PAGln, directly contributes to CVD.
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    Renal Denervation Update From the International Sympathetic Nervous System Summit: JACC State-of-the-Art Review
    (Elsevier, 2019-06-18) Kiuchi, Márcio G.; Esler, Murray D.; Fink, Gregory D.; Osborn, John W.; Banek, Christopher T.; Böhm, Michael; Denton, Kate M.; DiBona, Gerald F.; Everett, Thomas H., IV.; Grassi, Guido; Katholi, Richard E.; Knuepfer, Mark M.; Kopp, Ulla C.; Lefer, David J.; Lohmeier, Thomas E.; May, Clive N.; Mahfoud, Felix; Paton, Julian F.R.; Schmieder, Roland E.; Pellegrino, Peter R.; Sharabi, Yehonatan; Schlaich, Markus P.; Medicine, School of Medicine
    Three recent renal denervation studies in both drug-naïve and drug-treated hypertensive patients demonstrated a significant reduction of ambulatory blood pressure compared with respective sham control groups. Improved trial design, selection of relevant patient cohorts, and optimized interventional procedures have likely contributed to these positive findings. However, substantial variability in the blood pressure response to renal denervation can still be observed and remains a challenging and important problem. The International Sympathetic Nervous System Summit was convened to bring together experts in both experimental and clinical medicine to discuss the current evidence base, novel developments in our understanding of neural interplay, procedural aspects, monitoring of technical success, and others. Identification of relevant trends in the field and initiation of tailored and combined experimental and clinical research efforts will help to address remaining questions and provide much-needed evidence to guide clinical use of renal denervation for hypertension treatment and other potential indications.