Affiliations: [a] UMR Inserm U1134, Université des Antilles et de la Guyane, Pointe-à-Pitre, Guadeloupe, France
| [b] Laboratoire d’Excellence GR-Ex, PRES Sorbonne, Paris, France
| [c] Laboratoire CRIS EA647, Equipe “Biologie Vasculaire et du Globule Rouge”, Université Claude Bernard Lyon 1, France; Institut Universitaire de France, Paris, France
| [d]
Institute of Cardiovascular Research and Sports Medicine, Department of Molecular and Cellular Sports Medicine, German Sport University, Cologne, Germany
| [e] Unité Transversale de la Drépanocytose, Centre Hospitalier Universitaire de Pointe-à-Pitre, Pointe-à-Pitre, Guadeloupe, France
Correspondence:
[*]
Corresponding author: Philippe Connes, PhD, CRIS EA 647 Laboratory, Team “Vascular Biology and Red Blood Cell”, University Claude Bernard Lyon 1, Villeurbanne, France. Tel.: +33 472 43 16 25; E-mail: [email protected]; [email protected].
Abstract: Sickle cell anemia (SCA) is an inherited red blood cells (RBC) disorder characterized by significantly decreased RBC deformability. The present study aimed to assess whether modulation of RBC Nitric Oxide Synthase (RBC-NOS) activation could affect RBC deformability in SCA. Blood of twenty-five SCA patients was treated for 1 hour at 37°C with Phosphate Buffered Saline (PBS) or PBS containing 1% of Dimethylsulfoxyde as control, L-arginine or N(5)-(1-Iminoethyl)-L-ornithine (L-NIO) to directly stimulate or inhibit RBC-NOS, insulin or wortmannin to indirectly stimulate or inhibit RBC-NOS through their effects on the PI3 Kinase/Akt pathway, and sodium nitroprusside (SNP) and 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) as NO donor and NO scavenger, respectively. RBC deformability was measured by ektacytometry at 3 Pa. RBC deformability significantly increased after insulin treatment and significantly decreased after L-NIO and wortmannin incubation. The other conditions did not affect deformability. Significantly increased nitrotyrosine levels, a marker of enhanced free radical generation, were detected by immunohistochemistry in SNP and insulin treated samples. These data suggest that RBC deformability of SCA can be modulated by RBC-NOS activity but also that oxidative stress may impair effectiveness of RBC-NOS produced NO.
Keywords: Sickle cell disease, red blood cell rheology, nitric oxide
