Endothelial S100A1 Modulates Vascular Function via Nitric Oxide

• Published in: Circulation research Vol. 102; no. 7; pp. 786 - 794
• Main Authors: Pleger, Sven T, Harris, David M, Shan, Changguang, Vinge, Leif E, Chuprun, J Kurt, Berzins, Brett, Pleger, Wiebke, Druckman, Charles, Völkers, Mirko, Heierhorst, Jörg, Øie, Erik, Remppis, Andrew, Katus, Hugo A, Scalia, Rosario, Eckhart, Andrea D, Koch, Walter J, Most, Patrick
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD American Heart Association, Inc 11-04-2008; Lippincott
• Subjects: Acetylcholine - pharmacology; Animals; Aorta, Thoracic - metabolism; Aorta, Thoracic - pathology; Aorta, Thoracic - physiopathology; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; Calcium - metabolism; Cardiology. Vascular system; Disease Models, Animal; Endothelium, Vascular - metabolism; Endothelium, Vascular - pathology; Endothelium, Vascular - physiopathology; Female; Fundamental and applied biological sciences. Psychology; Heart Failure - metabolism; Heart Failure - pathology; Heart Failure - physiopathology; Humans; Hypertension - metabolism; Hypertension - pathology; Hypertension - physiopathology; Inositol 1,4,5-Trisphosphate Receptors - metabolism; Male; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide - metabolism; Nitroprusside - pharmacology; Rats; Rats, Wistar; S100 Proteins - metabolism; Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism; Vasoconstriction - drug effects; Vasoconstriction - physiology; Vasodilation - drug effects; Vasodilation - physiology; Vasodilator Agents - pharmacology; Vertebrates: cardiovascular system; Hypertension; endothelial function; NO; vascular function; Calcium; S100A1; Cardiovascular disease; Inorganic element; Endothelium; Vertebrata; Mammalia; Nitric oxide; Circulatory system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/CIRCRESAHA.108.172031

S100A1, a Ca-binding protein of the EF-hand type, is known to modulate sarcoplasmic reticulum Ca handling in skeletal muscle and cardiomyocytes. Recently, S100A1 has been shown to be expressed in endothelial cells (ECs). Because intracellular Ca ([Ca]i) transients can be involved in important EC functions and endothelial NO synthase activity, we sought to investigate the impact of endothelial S100A1 on the regulation of endothelial and vascular function. Thoracic aortas from S100A1 knockout mice (SKO) showed significantly reduced relaxation in response to acetylcholine compared with wild-type vessels, whereas direct vessel relaxation using sodium nitroprusside was unaltered. Endothelial dysfunction attributable to the lack of S100A1 expression could also be demonstrated in vivo and translated into hypertension of SKO. Mechanistically, both basal and acetylcholine-induced endothelial NO release of SKO aortas was significantly reduced compared with wild type. Impaired endothelial NO production in SKO could be attributed, at least in part, to diminished agonist-induced [Ca]i transients in ECs. Consistently, silencing endothelial S100A1 expression in wild type also reduced [Ca]i and NO generation. Moreover, S100A1 overexpression in ECs further increased NO generation that was blocked by the inositol-1,4,5-triphosphate receptor blocker 2-aminoethoxydiphenylborate. Finally, cardiac endothelial S100A1 expression was shown to be downregulated in heart failure in vivo. Collectively, endothelial S100A1 critically modulates vascular function because lack of S100A1 expression leads to decreased [Ca]i and endothelial NO release, which contributes, at least partially, to impaired endothelium-dependent vascular relaxation and hypertension in SKO mice. Targeting endothelial S100A1 expression may, therefore, be a novel therapeutic means to improve endothelial function in vascular disease or heart failure.