Identification of cellular targets pertinent for the development of effective therapies against pathological pain constitutes a difficult challenge. We combined several approaches to show that 3alpha-hydroxysteroid oxido-reductase (3alpha-HSOR), abundantly expressed in the spinal cord (SC), is a key target, the modulation of which markedly affects nociception. 3alpha-HSOR catalyzes the biosynthesis and oxidation of 3alpha,5alpha-reduced neurosteroids as allopregnanolone (3alpha,5alpha-THP), which stimulates GABA(A) receptors. Intrathecal injection of Provera (pharmacological inhibitor of 3alpha-HSOR activity) in naive rat SC decreased thermal and mechanical nociceptive thresholds assessed with behavioral methods. In contrast, pain thresholds were dose-dependently increased by 3alpha,5alpha-THP. In animals subjected to sciatic nerve injury-evoked neuropathic pain, molecular and biochemical experiments revealed an up-regulation of 3alpha-HSOR reductive activity in the SC. Enhancement of 3alpha,5alpha-THP concentration in the SC induced analgesia in neuropathic rats while Provera exacerbated their pathological state. Possibilities are opened for chronic pain control with drugs modulating 3alpha-HSOR activity in nerve cells.
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http://dx.doi.org/10.1016/j.nbd.2007.12.001 | DOI Listing |
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October 2016
M Laconi, Laboratorio de Fisiopatología ovárica y Neurobiología. , Instituto de Medicina y Biología Experimental de Cuyo (IMBECU-CONICET), Inbiomed-UM, Mendoza, Argentina
Allopregnanolone, a progesterone metabolite, is one of the best characterized neurosteroids. In a dose that mimics serum levels during stress, allopregnanolone inhibits sexual receptivity and ovulation and induces a decrease in luteinizing hormone levels. The aim of this work was to examine the effect of an intracerebroventricular administration of allopregnanolone on ovarian morphophysiology, serum and tissue levels of progesterone and estrogen, and enzymatic activity of 3β-hydroxysteroid dehydrogenase, 20α-hydroxysteroid dehydrogenase and 3α-hydroxysteroid oxido-reductase in the ovary and in the medial basal hypothalamus on the morning of estrus.
View Article and Find Full Text PDFProg Neurobiol
February 2014
Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France. Electronic address:
Because the treatment and management of neuropathic pain are extremely complicated, the characterization of novel analgesics and neuroprotectors with safe toxicological profiles is a crucial need to develop efficient therapies. Several investigations revealed that the natural neurosteroid allopregnanolone (AP) exerts analgesic, neuroprotective, antidepressant and anxiolytic effects. These effects result from AP ability to modulate GABA(A), glycine, L- and T-type calcium channels.
View Article and Find Full Text PDFPain
September 2010
Equipe Stéroïdes, Neuromodulateurs et Neuropathologies, Unité de Physiopathologie et Médecine Translationnelle, EA-4438, Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67000 Strasbourg, France.
The enzyme 3alpha-hydroxysteroid oxido-reductase (3alpha-HSOR) catalyzes the synthesis and bioavailability of 3alpha,5alpha-neurosteroids as allopregnanolone (3alpha,5alpha-THP) which activates GABA(A) receptors and blocks T-type calcium channels involved in pain mechanisms. Here, we used a multidisciplinary approach to demonstrate that 3alpha-HSOR is a cellular target the modulation of which in dorsal root ganglia (DRG) may contribute to suppress pain resulting from peripheral nerve injury. Immunohistochemistry and confocal microscope analyses showed 3alpha-HSOR-immunostaining in naive rat DRG sensory neurons and glial cells.
View Article and Find Full Text PDFJ Steroid Biochem Mol Biol
April 2008
Equipe Stéroïdes et Système Nociceptif, Institut des Neurosciences Cellulaires et Intégratives, Université Louis Pasteur, 67084 Strasbourg Cedex, France.
It has recently been demonstrated that the spinal cord (SC) is an active production center of neuroactive steroids including pregnenolone, dehydroepiandrosterone, progesterone and allopregnanolone. Indeed, anatomical, cellular and biochemical investigations have shown that the SC dorsal horn (DH), a pivotal structure in nociception, contains various active steroidogenic enzymes such as cytochrome P450side-chain-cleavage, cytochrome P450c17, 3beta-hydroxysteroid dehydrogenase, 5alpha-reductase and 3alpha-hydroxysteroid oxido-reductase. Reviewed here are several data obtained with in vitro and vivo experiments showing that endogenous steroids synthesized in the SC are involved in the modulation of nociceptive mechanisms.
View Article and Find Full Text PDFNeuroscience
April 2008
Equipe Stéroïdes et Système Nociceptif, Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique/Université Louis Pasteur, 21 rue René Descartes, 67084 Strasbourg Cedex, France.
The neurosteroid allopregnanolone (3alpha,5alpha-THP) is well characterized as a potentially therapeutic molecule which exerts important neurobiological actions including neuroprotective, antidepressant, anxiolytic, anesthetic and analgesic effects. We have recently observed that neurons and glial cells of the rat spinal cord (SC) contain various key steroidogenic enzymes such as 5alpha-reductase and 3alpha-hydroxysteroid oxido-reductase which are crucial for 3alpha,5alpha-THP biosynthesis. Furthermore, we demonstrated that the rat SC actively produces 3alpha,5alpha-THP.
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