title: Estrogen receptor-alpha predominantly mediates the salutary effects of 17beta-estradiol on splenic macrophages following trauma-hemorrhage.
abstract: Although 17beta-estradiol administration following trauma-hemorrhage prevents the suppression in splenic macrophage cytokine production, it remains unknown whether the salutary effects are mediated via estrogen receptor (ER)-alpha or ER-beta and which signaling pathways are involved in such 17beta-estradiol effects. Utilizing ER-alpha- or ER-beta-specific agonists, this study examined the role of ER-alpha and ER-beta in 17beta-estradiol-mediated restoration of macrophage cytokine production following trauma-hemorrhage. In addition, since MAPK and NF-kappaB are known to regulate macrophage cytokine production, we also examined the activation of those signaling molecules. Male rats underwent trauma-hemorrhage (mean arterial pressure of 40 mmHg for 90 min) and fluid resuscitation. The ER-alpha agonist propyl pyrazole triol (PPT; 5 microg/kg), the ER-beta agonist diarylpropionitrile (DPN; 5 microg/kg), 17beta-estradiol (50 microg/kg), or vehicle (10% DMSO) was injected subcutaneously during resuscitation. Twenty-four hours thereafter, splenic macrophages were isolated, and their IL-6 and TNF-alpha production and activation of MAPK and NF-kappaB were measured. Macrophage IL-6 and TNF-alpha production and MAPK activation were decreased, whereas NF-kappaB activity was increased, following trauma-hemorrhage. PPT or 17beta-estradiol administration after trauma-hemorrhage normalized those parameters. DPN administration, on the other hand, did not normalize the above parameters. Since PPT but not DPN administration following trauma-hemorrhage was as effective as 17beta-estradiol in preventing the suppression in macrophage cytokine production, it appears that ER-alpha plays the predominant role in mediating the salutary effects of 17beta-estradiol on macrophage cytokine production following trauma-hemorrhage and that such effects are likely mediated via normalization of MAPK but not NF-kappaB signaling pathways.
authors.affiliation: Center for Surgical Research and Dept. of Surgery, Univ. of Alabama, at Birmingham, 1670 Univ. Blvd., Volker Hall, Rm. G094, Birmingham, AL 35294-0019, USA.
authors.forename: Takao
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Shimizu
authors.forename: Huang-Ping
authors.initials: HP
authors.lastname: Yu
authors.forename: Ya-Ching
authors.initials: YC
authors.lastname: Hsieh
authors.forename: Mashkoor A
authors.initials: MA
authors.lastname: Choudhry
authors.forename: Kirby I
authors.initials: KI
authors.lastname: Bland
authors.forename: Irshad H
authors.initials: IH
authors.lastname: Chaudry
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism; D006470:Hemorrhage / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017695:Soft Tissue Injuries / Q000378:metabolism*; D013154:Spleen / Q000166:cytology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D015850:Interleukin-6; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D004958:Estradiol; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases