leukotriene-c4 and Aortic-Valve-Stenosis

Oxidative stress may contribute to the hemodynamic progression of aortic valve stenosis, and is associated with activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) 1. The aim of the present study was to assess the transcriptional profile and the topological distribution of PARP-1 in human aortic valves, and its relation to the stenosis severity. Human stenotic aortic valves were obtained from 46 patients undergoing aortic valve replacement surgery and used for mRNA extraction followed by quantitative real-time PCR to correlate the PARP-1 expression levels with the non invasive hemodynamic parameters quantifying the stenosis severity. Primary isolated valvular interstitial cells (VICs) were used to explore the effects of cytokines and leukotriene C(4) (LTC(4)) on valvular PARP-1 expression. The thickened areas of stenotic valves with tricuspid morphology expressed significantly higher levels of PARP-1 mRNA compared with the corresponding part of bicuspid valves (0.501 vs 0.243, P=0.01). Furthermore, the quantitative gene expression levels of PARP-1 were inversely correlated with the aortic valve area (AVA) (r=-0.46, P=0.0469) and AVA indexed for body surface area (BSA) (r=-0.498; P=0.0298) only in tricuspid aortic valves. LTC(4) (1nM) significantly elevated the mRNA levels of PARP-1 by 2.38-fold in VICs. Taken together, these data suggest that valvular DNA-damage pathways may be associated with inflammation and the stenosis severity in tricuspid aortic valves.

Topics: Adult; Aged; Aged, 80 and over; Aortic Valve Stenosis; DNA Damage; Female; Hemodynamics; Humans; Leukotriene C4; Male; Middle Aged; Mitral Valve; Oxidative Stress; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Severity of Illness Index; Transcription, Genetic; Tricuspid Valve

The development of aortic valve stenosis is not only associated with calcification and extracellular matrix remodeling, but also with inflammation. The aim of this study was to determine the role of proinflammatory signaling through the leukotriene (LT) pathway in aortic stenosis.. After macroscopic dissection of surgically removed human aortic valves, RNA was extracted from 311 preparations derived from 68 patients to differentiate normal, thickened, and calcified areas from each cusp. Subsequently, quantitative polymerase chain reaction analysis was used to correlate gene expression patterns with preoperative echocardiographic parameters. The messenger RNA levels of the LT-forming enzyme 5-lipoxygenase increased 1.6- and 2.2-fold in thickened and calcified tissue, respectively, compared with normal areas of the same valves. In thickened tissues, messenger RNA levels for 5-lipoxygenase (r= -0.35; P=0.03), its activating protein (5-lipoxygenase activating protein; r= -0.39; P=0.02), and LTA(4) hydrolase (r= -0.48; P=0.01) correlated inversely with the velocity-time integral ratio. In addition, leukotriene A(4) hydrolase transcripts correlated inversely with aortic valve area, indexed for body surface area (r= -0.52; P=0.007). Immunohistochemical stainings revealed LT receptor expression on valvular myofibroblasts. In primary cultures of human myofibroblasts derived from stenotic aortic valves, Leukotriene C(4) (LTC(4)) increased intracellular calcium, enhanced reactive oxygen species production, reduced the mitochondrial membrane potential, and led to morphological cell cytoplasm changes and calcification.. The upregulation of the LT pathway in human aortic valve stenosis and its correlation with clinical stenosis severity, taken together with the potentially detrimental LT-induced effects on valvular myofibroblasts, suggests one possible role of inflammation in the development of aortic stenosis.

Topics: Aged; Aortic Valve; Aortic Valve Stenosis; Arachidonate 5-Lipoxygenase; Cells, Cultured; Echocardiography; Female; Fibroblasts; Gene Expression Profiling; Humans; Immunohistochemistry; Leukotriene C4; Male; Middle Aged; Mitral Valve; Myocarditis; Receptors, Leukotriene; Severity of Illness Index; Signal Transduction; Tricuspid Valve; Up-Regulation