Genistein inhibits glutamate-induced apoptotic processes in primary neuronal cell cultures: an involvement of aryl hydrocarbon receptor and estrogen receptor/glycogen synthase kinase-3beta intracellular signaling pathway.
Phytoestrogens prevent neuronal damage, however, mechanism of their neuroprotective action has not been fully elucidated. This study aimed to evaluate the effects of genistein on glutamate-induced apoptosis in mouse primary neuronal cell cultures. Glutamate (1 mM) enhanced caspase-3 activity and lactate dehydrogenase (LDH) release in the hippocampal, neocortical and cerebellar neurons in time-dependent manner, and these data were confirmed at the cellular level with Hoechst 33342 and calcein AM staining. Genistein (10-10,000 nM) significantly inhibited glutamate-induced apoptosis, and the effect of this isoflavone was most prominent in the hippocampal cells. Next, we studied an involvement of estrogen and aryl hydrocarbon receptors in anti-apoptotic effects of genistein. A high-affinity estrogen receptor antagonist, ICI 182, 780 (1 microM), reversed, whereas less specific antagonist/partial agonist, tamoxifen (1 microM), either intensified or partially inhibited genistein effects. Aryl hydrocarbon receptor antagonist, alpha-naphthoflavone (1 microM), exhibited a biphasic action: it enhanced genistein action toward a short-term exposure (3 h) to glutamate, but antagonized genistein action toward prolonged exposure (24 h) to that insult. SB 216763 (1 microM), which preferentially inhibits glycogen synthase kinase-3beta (GSK-3beta), potentiated genistein effects. These data point to strong effects of genistein at low micromolar concentrations in various brain tissues against glutamate-evoked apoptosis. Moreover, this study provided evidence for involvement of aryl hydrocarbon receptor and estrogen receptor/GSK-3beta intracellular signaling pathway in anti-apoptotic action of genistein.
Kajta
M
M
Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Krakow, Poland. kajta@if-pan.krakow.pl
Domin
H
H
Grynkiewicz
G
G
Lason
W
W
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D002478:Cells, Cultured; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D019833:Genistein / Q000494:pharmacology* / Q000627:therapeutic use; D018698:Glutamic Acid / Q000633:toxicity; D038362:Glycogen Synthase Kinase 3 / Q000187:drug effects* / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006131:Growth Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use; D009498:Neurotoxins / Q000037:antagonists & inhibitors; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects*; D011960:Receptors, Estrogen / Q000819:agonists / Q000037:antagonists & inhibitors / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
D051017:Apoptosis Regulatory Proteins; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D006131:Growth Inhibitors; D018696:Neuroprotective Agents; D009498:Neurotoxins; D018336:Receptors, Aryl Hydrocarbon; D011960:Receptors, Estrogen; D018698:Glutamic Acid; D019833:Genistein; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3