Short communication The effects of fetal and perinatal asphyxia on neuronal cytokine levels and ceramide metabolism in adulthood Evi Vlassaks a, b, c , Antonio W.D. Gavilanes a, b, ⁎, Johan S.H. Vles a, c, d , Sarah Deville a , Boris W. Kramer a, b, c , Eveline Strackx a, b , Pilar Martinez-Martinez a a Department of Neuropsychology — Division Neuroscience, Maastricht University, School of Mental Health and Neuroscience (MHeNS), Maastricht 6200MD, The Netherlands b Department of Pediatrics — Division of Neonatology, Maastricht University Medical Center, Maastricht 6202AZ, The Netherlands c School for Oncology and Developmental Biology Maastricht (GROW), Maastricht University, Maastricht 6202AZ, The Netherlands d Child Neurology, Maastricht University Medical Center, Maastricht 6202AZ, The Netherlands abstract article info Article history: Received 12 July 2012 Received in revised form 15 September 2012 Accepted 17 September 2012 Keywords: Ceramides Neuroinflammation Perinatal asphyxia Preconditioning In a rat model of global fetal and perinatal asphyxia, we investigated if asphyxia and long-lasting brain toler- ance to asphyxia (preconditioning) are mediated by modifications in inflammatory cytokines and ceramide metabolism genes in prefrontal cortex, hippocampus and caudate-putamen at the age of 8 months. Most significant changes were found in prefrontal cortex, with reduced LAG1 homolog ceramide synthase 1 expression after both types of asphyxia. Additionally, sphingosine kinase 1 was upregulated in those animals that experienced the combination of fetal and perinatal asphyxia (preconditioning), suggesting increased cell proliferation. While cytokine levels are normal, levels of ceramide genes were modulated both after fetal and perinatal asphyxia in the adult prefrontal cortex. Moreover, the combination of two subsequent asphyctic insults pro- vides long-lasting neuroprotection in the prefrontal cortex probably by maintaining normal apoptosis and promoting cell proliferation. Better understanding of the effects of asphyxia on ceramide metabolism will help to understand the changes leading to brain tolerance and will open opportunities for the development of new neuroprotective therapies. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Perinatal asphyxia (PA) is one of the most common causes of neona- tal morbidity and mortality (Berger and Garnier, 1999; Lawn et al., 2004). Because of the lack of effective therapies, besides hypothermia (Perlman, 2006), there is a high need for new approaches to treat infants suffering from asphyxia. Previously, we showed in a rat model of global asphyxia that the combination of a mild fetal asphyctic (FA) insult and a subsequent severe PA insult (=FA–PA; preconditioning) provided long-lasting protection against neuronal deficits normally observed after PA alone (Strackx et al., 2010a). Gaining more insights into these mechanisms leading to brain tolerance will help the develop- ment of new specific therapeutics. Ceramides are bioactive lipids which have emerged as important regulators of cell activation with a wide spectrum of activities ranging from the control of cell growth to cell death (Mencarelli et al., 2010) and have been shown to be upregulated in hypoxic-ischemic brain damage (Ohtani et al., 2004; Novgorodov and Gudz, 2009). Besides the changes in lipid metabolism, asphyxia triggers an inflammatory response (Hagberg et al., 1996; Maslinska et al., 2002; Aly et al., 2006; Okazaki et al., 2006). The cytokines produced in this inflamma- tory response are suggested to affect the lipid metabolism in the brain (Adibhatla et al., 2008) and in particular tumor necrosis factor (TNF)-α is recognized as an important stimulus for ceramide generation (Dbaibo et al., 1993). TNF-α also activates the promoter region of ceramide transporter (CERT) and Goodpasture antigen-binding protein (GPBP) (Mencarelli et al., 2010), suggesting the involvement of these ceramide transporters in asphyctic brain damage as well. We hypothesized that long-lasting brain tolerance to asphyxia is partly mediated by modifications of genes involved in inflammation and ceramide metabolism. To study this, a validated rat model was used (Strackx et al., 2010a,b). The prefrontal cortex, hippocampus and caudate-putamen (cpu) were examined for long-term changes in cyto- kine levels and enzymes and transporters involved in ceramide metabo- lism at the middle age of 8 months. Most significant changes were observed in prefrontal cortex, suggesting long-lasting neuroprotection in FA-PA animals by promoting cell proliferation in the prefrontal cortex. 2. Material and methods 2.1. Animals and tissue processing All experiments were approved by the Animal Ethics Board of Maas- tricht University on animal welfare according to Dutch governmental Journal of Neuroimmunology 255 (2013) 97–101 ⁎ Corresponding author at: Department of Pediatrics, Maastricht University Medical Centre, Postbus 5800, 6202AZ Maastricht, The Netherlands. Tel.: + 31 43 3876061; fax: +31 43 3875246. E-mail address: danilo.gavilanes@mumc.nl (A.W.D. Gavilanes). 0165-5728/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jneuroim.2012.09.011 Contents lists available at SciVerse ScienceDirect Journal of Neuroimmunology journal homepage: www.elsevier.com/locate/jneuroim