CONICET | Buscador de Institutos y Recursos Humanos

NEUROSTEROIDOGENESIS AND PROGESTERONE ANTI-INFLAMMATORY/ NEUROPROTECTIVE EFFECTS.De Nicola A.F. *,** , a, Garay L. *, **, Meyer M. *, Sitruk-Ware R. ?, Guennoun R. , Schumacher M. , Gonzalez Deniselle M.C. *, ***. * Dept. of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, 1425 Buenos Aires, Argentina** Instituto de Biologia y Medicina Experimental-CONICET, 1428 Buenos Aires, Argentina- U1195 Inserm and Université Paris-Sud, 94276 Le Kremlin-Bicêtre, France.? The Population Council, New York, NY 10021, USA.*** Dept. of Physiology and Biophysics, Faculty of Medicine, University of Buenos Aires, 1425 Buenos Aires, Argentina. a Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental-CONICET, Obligado 2490, 1428 Buenos Aires, Argentina. Email address alejandrodenicola@gmail.com. Fax: +54.11.47862564. Multiple sclerosis (MS) is a neurological autoimmune/neurodegenerative disorder [8] that affects about 2.5 million people worldwide, according to WHO reports. A role for steroid hormones in MS is suggested because relapses decline during the last trimester of pregnancy, when estrogens and progesterone levels are high, and resume when steroids decay after delivery [2]. A commonly used model of MS is experimental autoimmune encephalomyelitis (EAE), induced in rodents by immunization with myelin peptides. We and others have shown that progesterone treatment decreases inflammatory cell infiltration and proinflammatory markers (TNFalpha, TNFR1, TLR4), increases myelination and attenuates clinical grade of EAE rodents [3-6]. The anti-inflammatory effects of progesterone in EAE are reminiscent of the changes from a TH1 to a TH2 response exerted by this steroid in pregnancy. In EAE, some of the progesterone effects may involve the classical progesterone receptor (PR), because the high affinity PR agonist Nestorone® decreases clinical grade, improves motor behaviour and decreases reactive microglia of EAE mice [6]. `Since neurosteroids have been implicated as protective factors for MS and EAE [3,7] we analyzed the mRNA expression of neurosteroidogenic enzymes in the spinal cord, a major target of EAE. Because mitochondria are the initial site of neurosteroid synthesis, we also analyzed mitochondrial morphology and dynamics (fusion and fission proteins). EAE was induced in female C57Bl6 mice using MOG40-54 and killed on day 16 after induction. Progesterone was given by pellet implantation 1 week before EAE induction. Using qPCR, we found in steroid-untreated EAE mice decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), P450scc (cholesterol side-chain cleavage), 5-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSD) and aromatase, whereas levels of 3-hydroxysteroid dehydrogenase (3-HSD) showed a large intra-group variance. We also found increased mRNA expression of 18 Kd translocator protein (TSPO), which likely resulted from the reactive microgliosis in this model. EAE mice also showed pathological mitochondrial morphology in axons and neuronal body, and reduced expression of fission and fusion protein mRNAs. Most importantly, pretreatment with progesterone before EAE induction increased Star,VDAC, P450scc, 5-reductase type I, 3α-HSD and aromatase mRNAs and did not modify 3-HSD. TSPO mRNA was decreased, consequent with the inhibition of microgliosis. Mitochondrial morphology was improved and fission/fusion protein mRNAs were enhanced by progesterone treatment. Furthermore, progesterone protective effects on mitochondrial and endoplasmic reticulum may allow the recovery of neurosteroidogenesis. In addition to progestins and estrogens, the enzymes 3-HSD, 3-HSD and 5-reductase are also responsible for the formation of androgens. Since androgen levels are modified in MS patients and EAE models [1,3], it is likely that together with progestins and estrogens, neuroandrogens may play a protective role for EAE and MS outcome. Our present data suggest that enhanced synthesis of neurosteroids in the spinal cord may reinforce the neuroprotective and anti-inflammatory effects of exogenous progesterone given to EAE mice.Reference List[1] Caruso D., G. D'Intino, S. Giatti, O. Maschi, M. Pesaresi, D. Calabrese, L.M. Garcia-Segura, L. Calza , R.C. Melcangi., Sex-dimorphic changes in neuroactive steroid levels after chronic experimental autoimmune encephalomyelitis, J Neurochem. 114 (2010) 921-932.[2] Confavreux C., M. Hutchinson, M. M. Hours, P. Cortinovis-Tourniaire, T. Moreau, Rate of pregnancy-related relapse in multiple sclerosis. Pregnancy in Multiple Sclerosis Group, N Engl J Med. 339 (1998) 285-291[3] Giatti, S., D. Caruso, M. Boraso, F. Abbiati, E. Ballarini, D. Calabrese, M. Pesaresi, R. Rigolio, M. Santos-Galindo, B. Viviani, G. Cavaletti, L.M. Garcia-Segura, R.C. Melcangi., Neuroprotective effects of progesterone in chronic experimental autoimmune encephalomyelitis, J Neuroendocrinol. 24 (2012) 851-861.[4] Garay L., M. C. Gonzalez Deniselle, A. Lima, P. Roig, A. F. De Nicola, Effects of progesterone in the spinal cord of a mouse model of multiple sclerosis, J Steroid Biochem Mol Biol. 107 (2007) 228-237.[5] Garay L., M. C. Gonzalez Deniselle, M. E. Brocca, A. Lima, P. Roig, A. F. De Nicola, Progesterone down-regulates spinal cord inflammatory mediators and increases myelination in experimental autoimmune encephalomyelitis, Neuroscience. 226 (2012) 40-50. [6] Garay L., M. C. Gonzalez Deniselle, R. Sitruk-Ware, R. Guennoun, M. Schumacher, A. F. De Nicola, Efficacy of the selective progesterone receptor agonist Nestorone for chronic experimental autoimmune encephalomyelitis, J Neuroimmunol. 276 (2014) 89-97. [7] Noorbakhsh F. , K. K. Ellestad, F. Maingat, K. G. Warren, M. H. Han, L. Steinman, G.B. Baker, C. Power., Impaired neurosteroid synthesis in multiple sclerosis, Brain. 134 (2011) 2703-2721.[8] Trapp B.D., K. A. Nave, Multiple sclerosis: an immune or neurodegenerative disorder?, Annu Rev Neurosci. 31 (2008) 247-269.