title: Estradiol protects PC12 cells against CoCl2-induced apoptosis.
abstract: In hypoxic/ischemic conditions, neuronal apoptotic events are occurred, resulting in neuronal diseases. Estradiol is a female sex hormone with steroid structure known to provide neuroprotection through multiple mechanisms in the central nervous system. This study was aimed to investigate the signal transduction pathway leading to the inhibitory effects of estradiol against cobalt chloride (CoCl(2))-mediated hypoxic death in PC12 cells. Estradiol inhibits CoCl(2)-induced cell death with genomic DNA fragmentation and morphologic changes such as cell shrinkage and condensed nuclei. Pre-incubation of estradiol prior to CoCl(2) treatment attenuated CoCl(2)-mediated the reactive oxygen species (ROS) production and limited the activities of the caspase cascades, such as caspase-8, -9 and -3. Furthermore, estradiol downregulated the Bax:Bcl-2 ratio and decreased the release of cytochrome c from the mitochondria into the cytosol in CoCl(2)-treated cells, indicating that estradiol affect on mitochondrial pathway. Estradiol attenuated also CoCl(2)-induced upregulation of Fas-ligand (Fas-L) and truncated of Bid in sequence of death receptor-mediated pathway. In addition, estradiol increased the phosphorylation of Akt in CoCl(2)-treated cells, demonstrating that estradiol has no affect on upstream signaling through the PI3K/Akt in inhibition of CoCl(2)-induced apoptosis in PC12 cells. Taken together, estradiol was found to have a neuroprotective effect against CoCl(2)-induced apoptosis of PC12 cells by the attenuating ROS production and the modulating apoptotic signal pathway through Bcl-2 family, cytochrome c, Fas/Fas-L as well as PI3K/Akt pathway.
authors.affiliation: Dental Science Research Institute, 2nd Stage of Brain Korea 21 Project for School of Dentistry, Chonnam National University School of Dentistry, Gwangju 500-757, South Korea. jjy@chonnam.ac.kr
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Jung
authors.forename: Kwang Hoon
authors.initials: KH
authors.lastname: Roh
authors.forename: Yeon Jin
authors.initials: YJ
authors.lastname: Jeong
authors.forename: Sun Hun
authors.initials: SH
authors.lastname: Kim
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.forename: Min Seok
authors.initials: MS
authors.lastname: Kim
authors.forename: Won Mann
authors.initials: WM
authors.lastname: Oh
authors.forename: Hee Kyun
authors.initials: HK
authors.lastname: Oh
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D003035:Cobalt / Q000633:toxicity*; D045304:Cytochromes c / Q000032:analysis / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004587:Electrophoresis, Agar Gel / Q000379:methods; D004789:Enzyme Activation / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology; D053222:Fas Ligand Protein / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism
chemical_list: D004967:Estrogens; D053222:Fas Ligand Protein; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; D019014:fas Receptor; D003035:Cobalt; D004958:Estradiol; D045304:Cytochromes c; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; C018021:cobaltous chloride