Uncoupling Caveolae From Intracellular Signaling In Vivo

• Published in: Circulation research Vol. 118; no. 1; pp. 48 - 55
• Main Authors: Kraehling, Jan R, Hao, Zhengrong, Lee, Monica Y, Vinyard, David J, Velazquez, Heino, Liu, Xinran, Stan, Radu V, Brudvig, Gary W, Sessa, William C
• Format: Journal Article
• Language: English
• Published: United States American Heart Association, Inc 08.01.2016
• Subjects: Animals; Blood Pressure - drug effects; Blood Pressure - physiology; Caveolae - drug effects; Caveolae - metabolism; Caveolin 1 - biosynthesis; Caveolin 1 - genetics; Doxycycline - pharmacology; Humans; Intracellular Fluid - drug effects; Intracellular Fluid - metabolism; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Nitric Oxide - metabolism; Signal Transduction - drug effects; Signal Transduction - physiology; Uncoupling Agents - pharmacology; caveolin-1; vascular function; eNOS; nitric oxide; mice; cell endothelial cell
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/CIRCRESAHA.115.307767

RATIONALE:Caveolin-1 (Cav-1) negatively regulates endothelial nitric oxide (NO) synthase–derived NO production, and this has been mapped to several residues on Cav-1, including F92. Herein, we reasoned that endothelial expression of an F92ACav-1 transgene would let us decipher the mechanisms and relationships between caveolae structure and intracellular signaling. OBJECTIVE:This study was designed to separate caveolae formation from its downstream signaling effects. METHODS AND RESULTS:An endothelial-specific doxycycline-regulated mouse model for the expression of Cav-1-F92A was developed. Blood pressure by telemetry and nitric oxide bioavailability by electron paramagnetic resonance and phosphorylation of vasodilator–stimulated phosphoprotein were determined. Caveolae integrity in the presence of Cav-1-F92A was measured by stabilization of caveolin-2, sucrose gradient, and electron microscopy. Histological analysis of heart and lung, echocardiography, and signaling were performed. CONCLUSIONS:This study shows that mutant Cav-1-F92A forms caveolae structures similar to WT but leads to increases in NO bioavailability in vivo, thereby demonstrating that caveolae formation and downstream signaling events occur through independent mechanisms.