Estrogen affects levels of Bcl-2 protein and mRNA in medial amygdala of ovariectomized rats.
The survival factor Bcl-2 is a cyclic AMP response element-binding protein (CREB) gene product implicated in mediating some of estrogen's effects on neuroprotection. Previously, we showed an effect of estradiol benzoate (E) on numbers of neuron-specific protein (NeuN)- and phosphorylated CREB (pCREB)-positive cells in medial (MeA), but not central (CeA), amygdala of ovariectomized rats. To determine whether these effects are accompanied by an E-induced increase in Bcl-2, we examined the effects of E on levels of Bcl-2 protein and mRNA in MeA and CeA of ovariectomized rats treated with E regimens resulting in moderate (2.5 microg E for 4 or 14 days) or high (10 microg E for 14 days) plasma estradiol levels. As a physiological control, we showed that all E treatments increased uterine wet weight relative to vehicle; 10 microg E for 14 days also increased uterine weight compared with that seen with lower E levels. Western blot analysis revealed that all E groups displayed an increase in uterine Bcl-2 protein levels compared with vehicle. We found that 2.5 microg and 10 microg E for 14 days increased levels of Bcl-2 gold immunolabeling compared with vehicle and 2.5 microg E for 4 days in MeA, but not CeA. We measured Bcl-2 mRNA levels in vehicle and 2.5 microg E-treated 14-day groups. There was a significant increase in Bcl-2 mRNA levels in MeA, but not CeA, of E-treated ovariectomized rats compared with vehicle controls. The E-induced increase in protein and mRNA levels of Bcl-2 in MeA may be important for neuroprotection in this region.
Fan
Lu
L
Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA.
Pandey
Subhash C
SC
Cohen
Rochelle S
RS
D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology; D004967:Estrogens / Q000097:blood* / Q000494:pharmacology; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D018696:Neuroprotective Agents / Q000097:blood / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects / Q000502:physiology; D010052:Ovariectomy; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014599:Uterus / Q000187:drug effects / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; D004967:Estrogens; D018696:Neuroprotective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; C074283:estradiol 3-benzoate; D004958:Estradiol