Because STX is a selective ligand for membrane estrogen receptors it may be able to confer the beneficial effects of estrogen without eliciting the deleterious side effects associated with activation of the nuclear estrogen receptors. death mitochondrial dysfunction dendritic simplification and synaptic loss induced by Aβ. STX prevented Aβ-induced cell death in both neuroblastoma cell lines; it also normalized the decrease in ATP and mitochondrial gene manifestation caused by Aβ in these cells. Notably STX also improved ATP content material and mitochondrial gene manifestation in control neuroblastoma cells (in the absence of Aβ). Similarly in main neurons STX improved ATP levels and mitochondrial gene manifestation in both genotypes. In addition STX treatment enhanced dendritic arborization and spine densities in WT neurons and prevented the diminished outgrowth of dendrites caused by Aβ exposure in Tg2576 neurons. These data suggest that STX can act as an effective neuroprotective agent in the context of Aβ toxicity improving mitochondrial function as well as dendritic growth and synaptic differentiation. In addition since STX also improved these endpoints in the absence of Aβ this compound may have broader therapeutic value beyond PNU-120596 Alzheimer’s disease. and models of amyloid pathology [22-27]. Several estrogen-dependent signaling pathways converge on mitochondria to modulate cellular respiration and ATP production [28-30]. E2 has been shown to enhance mind mitochondrial function [31] increase mitochondrial respiratory capacity [32] and induce the manifestation of mitochondrial proteins [29 32 E2 offers likewise been shown to protect against Aβ-induced cell death [33-35] and [36 37 and to attenuate bioenergetic deficits induced by Aβ in both neuroblastoma cells [38] and mouse models of AD [39 40 Despite the growing literature describing the beneficial action of estradiol on mind mitochondrial function in the context of AD comparatively little is known about the ability of SERMs (acting via extranuclear ERs) to recapitulate these neuroprotective effects. We have now addressed this problem by analyzing the neuroprotective effects of STX on cell viability mitochondrial function and neuronal morphology in several models of Aβ toxicity. METHODS STX preparation STX was produced by PNU-120596 AAPharmaSyn LLC (Ann Arbor MI) under contract with the authors of PNU-120596 the synthetic protocol for STX published in Tobias [41]. Stock solutions of STX (2 mM) were prepared PNU-120596 in 100% anhydrous dimethyl sulfoxide (DMSO) which was then diluted to operating concentrations in tradition medium as explained below. MC65 Cell tradition MC65 cells were cultured in MEMα supplemented with 10% fetal bovine serum (FBS; GIBCO/Existence Systems) 2 mM L-glutamine (Sigma-Aldrich) and 0.1% tetracycline (Sigma-Aldrich). For each experiment cells were trypsinized and resuspended in Opti-MEM without phenol reddish (GIBCO/Life Systems) then treated with STX or matched DMSO concentrations in the presence and absence of tetracycline. All endpoints were compared to those acquired with tetracycline-treated Rabbit Polyclonal to BAX. cells either with or without the addition of STX. For assays of viability cells were plated at 10 0 cells/well in 96 well plates and assessed after 72 hr of continuous treatment. For assays of gene manifestation and ATP dedication cells were plated at 60 0 cells/well in 12 well plates and were harvested after 48 hr of continuous treatment. SH-SY5Y Cell Tradition SH-SY5Y neuroblastoma cells were cultured in DMEM/F12 medium (GIBCO/Life Systems) supplemented with 10% FBS and 1% penicillin-streptomycin (Sigma-Aldrich). For assays of gene manifestation and ATP production PNU-120596 cells were plated at 200 0 cells/well in 12-well plates. For assays of cell viability cells were plated at 15 0 cells/well in 96 well plates. Three days after plating cells were washed with phosphate-buffered saline (PBS) and switched to serum-free DMEM/F12 medium comprising 1% N-2 growth supplement (GIBCO/Existence Systems) plus STX (100 nM). The following day time the cells were treated with 50 μM Aβ25-35 (American Peptide Organization) a fragment that has been shown to recapitulate the harmful effects of full-length Aβ[42 43 Aβ25-35 solutions were incubated at 37° C for 72 hr prior to addition to the cell.