title: Different degrees of NADPH oxidase 2 regulation and in vivo platelet activation: lesson from chronic granulomatous disease.
abstract: BACKGROUND
  In vitro study showed that NADPH oxidase (NOx), the most important enzyme producing reactive oxygen species (ROS), plays a role in the process of platelet activation. However, it is unclear if changes in its activity affect platelet activation in vivo.
  
  
  RESULTS
  In vivo and ex vivo experiments assessing platelet activation were investigated in healthy subjects, obese patients, and subjects with different low rates of NOx2 activity, namely X-linked chronic granulomatous disease (X-CGD) patients and X-CGD carriers. We included 27 X-CGD patients, 31 women carriers of hereditary deficiency of NOx2, 31 obese women, and 62 healthy subjects matched for sex and age. Plasma levels of soluble sCD40 L (sCD40L) and soluble P (sP)-selectin, 2 markers of in vivo platelet activation, were reduced in X-CGD patients (sCD40L=-55%; sP-selectin=-51%, P<0.001) and in X-CGD carriers (sCD40L=-41%; sP-selectin=-57%, P<0.001) compared with respective controls. Conversely, obese women, who disclosed NOx2 upregulation, had significantly higher plasma levels of sCD40L (+47%, P<0.001) and sP-selectin (+70%, P<0.001) compared with controls. Ex vivo study showed platelet isoprostane downexpression and enhanced platelet NO generation in both X-CGD patients and X-CGD carriers compared with controls; opposite findings were observed in obese patients. Correlation analysis showed that platelet NOx2 regulation was directly associated with plasma levels of sCD40L (R=0.336, P<0.001) and sP-selectin (R=0.441; P<0.001).
  
  
  CONCLUSIONS
  The study provides the first evidence that in vivo platelet activation is significantly and directly associated with NOx2 activity. Platelet NOx2 may be a novel target for platelet activation inhibition.
authors: Divisione I Clinica Medica, Department of Internal Medicine and Medical Specialities, University of Rome "La Sapienza", Rome, Italy (R.C., L.L., P.P., F.V.).
authors: Roberto
authors: R
authors: Carnevale
authors: Divisione I Clinica Medica, Department of Internal Medicine and Medical Specialities, University of Rome "La Sapienza", Rome, Italy (R.C., L.L., P.P., F.V.).
authors: Lorenzo
authors: L
authors: Loffredo
authors: Department of Internal Medicine, University of Rome "Tor Vergata", Rome, Italy (V.S.).
authors: Valerio
authors: V
authors: Sanguigni
authors: Department of Pediatrics and Institute of Molecular Medicine "A. Nocivelli", University of Brescia, Brescia, Italy (A.P., A.R.S.).
authors: Alessandro
authors: A
authors: Plebani
authors: University-Hospital Pediatric Department, Bambino Gesu` Children Hospital-University of Rome Tor Vergata, Rome, Italy (P.R., A.F.).
authors: Paolo
authors: P
authors: Rossi
authors: Department of Translational Medical Sciences, Federico II University, Naples, Italy (C.P., E.C.).
authors: Claudio
authors: C
authors: Pignata
authors: Department of Biomedicine and Evolutive Aging, University of Bari, Bari, Italy (B.M.).
authors: Baldassarre
authors: B
authors: Martire
authors: University-Hospital Pediatric Department, Bambino Gesu` Children Hospital-University of Rome Tor Vergata, Rome, Italy (P.R., A.F.).
authors: Andrea
authors: A
authors: Finocchi
authors: IRCSS Foundation Ca' Granda, University of Milan, Milan, Italy (M.C.P.).
authors: Maria Cristina
authors: MC
authors: Pietrogrande
authors: Department of Pediatrics, University of Florence, Florence, Italy (C.A.).
authors: Chiara
authors: C
authors: Azzari
authors: Department of Pediatrics and Institute of Molecular Medicine "A. Nocivelli", University of Brescia, Brescia, Italy (A.P., A.R.S.).
authors: Anna Rosa
authors: AR
authors: Soresina
authors: Department of Pediatrics, University of Turin, Turin, Italy (S.M.).
authors: Silvana
authors: S
authors: Martino
authors: Department of Translational Medical Sciences, Federico II University, Naples, Italy (C.P., E.C.).
authors: Emilia
authors: E
authors: Cirillo
authors: Department of Pediatrics, Center of Clinic Lipid Research, University of Rome "La Sapienza", Rome, Italy (F.M.).
authors: Francesco
authors: F
authors: Martino
authors: Divisione I Clinica Medica, Department of Internal Medicine and Medical Specialities, University of Rome "La Sapienza", Rome, Italy (R.C., L.L., P.P., F.V.).
authors: Pasquale
authors: P
authors: Pignatelli
authors: Divisione I Clinica Medica, Department of Internal Medicine and Medical Specialities, University of Rome "La Sapienza", Rome, Italy (R.C., L.L., P.P., F.V.).
authors: Francesco
authors: F
authors: Violi
mesh_terms: D000293:Adolescent; D000328:Adult; D001792:Blood Platelets / Q000201:enzymology; D023201:CD40 Ligand / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006105:Granulomatous Disease, Chronic / Q000097:blood / Q000201:enzymology* / Q000503:physiopathology; D006579:Heterozygote; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000502:physiology*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism / Q000502:physiology*; D009765:Obesity / Q000097:blood / Q000201:enzymology / Q000503:physiopathology; D019007:P-Selectin / Q000097:blood; D015539:Platelet Activation / Q000502:physiology*
chemical_list: D008562:Membrane Glycoproteins; D019007:P-Selectin; D023201:CD40 Ligand; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases
keywords: NOx2; X‐CGD; oxidative stress; platelet activation