Effect of 17beta-estradiol on signal transduction pathways and secondary damage in experimental spinal cord trauma.
Because studies have shown that 17beta-estradiol (E2) produces anti-inflammatory effects after various adverse circulatory conditions, we examined whether administration of E2 before spinal cord injury (SCI) has any salutary effects in reducing SCI. Spinal cord injury was induced by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. To gain a better insight into the mechanism of action of the anti-inflammatory effects of E2, the following end points of the inflammatory process were evaluated: (1) spinal cord inflammation and tissue injury (histological score); (2) neutrophil infiltration (myeloperoxidase activity); (3) expression of iNOS, nitrotyrosine, and COX-2; (4) apoptosis (terminal deoxynucleotidyltransferase-mediated UTP end labeling staining and Bax and Bcl-2 expression); and (5) tissue TNF-alpha, IL-6, IL-1beta, and monocyte chemoattractant protein 1 levels. In another set of experiments, the pretreatment or posttreatment with E2 significantly ameliorates the recovery of limb function (evaluated by motor recovery score). To elucidate whether the protective effects of E2 were mediated via the estrogen receptors, we investigated the effect of an estrogen receptor antagonist, ICI 182,780, on the protective effects of E2. ICI 182,780 (500 microg/kg, s.c., 1 h before treatment with E2) significantly antagonized the effect of the E2 and abolished the protective effect against SCI. Taken together, our results clearly demonstrate that administration of E2 before SCI reduces the development of inflammation and tissue injury associated with spinal cord trauma.
Cuzzocrea
Salvatore
S
Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy. salvator@unime.it
Genovese
Tiziana
T
Mazzon
Emanuela
E
Esposito
Emanuela
E
Di Paola
Rosanna
R
Muià
Carmelo
C
Crisafulli
Concetta
C
Peli
Angelo
A
Bramanti
Placido
P
Chaudry
Irshad H
IH
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D018925:Chemokines / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004958:Estradiol / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013119:Spinal Cord Injuries / Q000235:genetics / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C494827:Bax protein, mouse; D018925:Chemokines; D016207:Cytokines; D017931:DNA Primers; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C002744:3-nitrotyrosine; D014443:Tyrosine; D004958:Estradiol; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2