ORIGINAL ARTICLE Experimental and clinical evidence of differential effects of magnesium sulfate on neuroprotection and angiogenesis in the fetal brain Matthieu Lecuyer 1 , Marina Rubio 2 , Cl ement Chollat 1,3,4 , Maryline Lecointre 1 , Sylvie J egou 1 , Philippe Leroux 1 , Carine Cleren 1 , Isabelle Leroux-Nicollet 1 , Loic Marpeau 1,5 , Denis Vivien 2 , St ephane Marret 1,3 & Bruno J.Gonzalez 1 1 Normandie University, UNIROUEN, INSERM U1245 NeoVasc Team, Rouen University Hospital, IRIB, F76000 Normandy Centre for Genomic and Personalized Medicine, Rouen, France 2 INSERM U1237 unit “Serine proteases and Pathophysiology of the neurovascular Unit”, Normandy University, Caen, France 3 Department of Neonatal Paediatrics and Intensive Care, Rouen Hospital, Rouen, France 4 Department of Neonatal Intensive Care, Port-Royal University Hospital, APHP, Paris, France 5 Department of Obstetrics, Rouen Hospital, Rouen, France Keywords Cerebral palsy, Hif, Neurovascular, side effects, translational medicine Correspondence Bruno J. Gonzalez, Normandy University, UNIRouen, Inserm U1245, Faculty of Medicine, Laboratory of Microvascular Endothelium and Neonatal Brain Lesions, 76183 Rouen Cedex, France. Tel: 33 (0) 235 148 547; E-mail: bruno.gonzales@univ-rouen.fr Funding Information This work was supported by INSERM, Normandy University, the Regional Platform for Cell Imaging PRIMACEN, the Conseil R egional de Haute-Normandie, FEDER DO-IT, and the LARC-Neuroscience Network. L.M. was the recipient of a fellowship from the Conseil R egional de Haute-Normandie. Received: 14 October 2016; Revised: 5 January 2017; Accepted: 10 January 2017 Pharma Res Per, 5(4), 2017, e00315, https//org.doi/10.1002/prp2.315 doi: 10.1002/prp2.315 Abstract Clinical studies showed beneficial effects of magnesium sulfate regarding the risk of cerebral palsy. However, regimen protocols fluctuate worldwide and risks of adverse effects impacting the vascular system have been reported for human neo- nates, keeping open the question of the optimal dosing. Using clinically relevant concentrations and doses of magnesium sulfate, experiments consisted of charac- terizing, respectively, ex vivo and in vivo, the effects of magnesium sulfate on the nervous and vascular systems of mouse neonates by targeting neuroprotection, angiogenesis, and hemodynamic factors and in measuring, in human fetuses, the impact of a 4-g neuroprotective loading dose of magnesium sulfate on brain hemodynamic parameters. Preclinical experiments using cultured cortical slices from mouse neonates showed that the lowest and highest tested concentrations of magnesium sulfate were equally potent to prevent excitotoxic-induced cell death, cell edema, cell burst, and intracellular calcium increase, whereas no side effects were found regarding apoptosis. In contrast, in vivo data revealed that magnesium sulfate exerted dose-dependent vascular effects on the fetal brain. In particular, it induced brain hypoperfusion, stabilization of Hif-1a, long-term upregulation of VEGF-R2 expression, impaired endothelial viability, and altered cortical angio- genesis. Clinically, in contrast to 6-g loading doses used in some protocols, a 4-g bolus of magnesium sulfate did not altered fetal brain hemodynamic parameters. In conclusion, these data provide the first mechanistic evidence of double-sword and dose-dependent actions of magnesium sulfate on nervous and vascular sys- tems. They strongly support the clinical use of neuroprotection protocols vali- dated for the lowest (4-g) loading dose of magnesium sulfate. Abbreviations 7-AAD, 7-aminoactinomycin D; aCS, artificial cerebrospinal fluid; CP, cerebral palsy; GD15, gestational day 15; LDH, lactate dehydrogenase; MCA, middle cerebral artery; MgSO 4 , magnesium sulfate; NADH, b-nicotinamide adenine dinucleotide; NADPH, b-nicotinamide adenine dinucleotide 2 0 -phosphate reduced tetrasodium salt hydrate; NMRI, National Marine Research Institute; P2, postnatal day 2; PI, pulsatility index; PMSF, phenylmethanesulfonyl fluoride; RI, resistance index; ROI, region of interest; WG, week of gestation. ª 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 2017 | Vol. 5 | Iss. 4 | e00315 Page 1