title: Activation of GluR6-containing kainate receptors induces ubiquitin-dependent Bcl-2 degradation via denitrosylation in the rat hippocampus after kainate treatment.
abstract: We previously showed that Bcl-2 (B-cell lymphoma 2) is down-regulated in a kainate (KA)-induced rat epileptic seizure model. The underlying mechanism had remained largely unknown, but we here report for the first time that denitrosylation and ubiquitination are involved. Our results show that the S-nitrosylation levels of Bcl-2 are down-regulated after KA injection and that the GluR6 (glutamate receptor 6) antagonist NS102 can inhibit the denitrosylation of Bcl-2. Moreover, the ubiquitin-dependent degradation of Bcl-2 was found to be promoted after KA treatment, which could be suppressed by the proteasome inhibitor MG132 and the NO donors, sodium nitroprusside and S-nitrosoglutathione. In addition, experiments based on siRNA transfections were performed in the human SH-SY5Y neuroblastoma cell line to verify that the stability of Bcl-2 is causal to neuronal survival. At the same time, it was found that the exogenous NO donor GSNO could protect neurons when Bcl-2 is targeted. Subsequently, these mechanisms were morphologically validated by immunohistochemistry, cresyl violet staining, and in situ TUNEL staining to analyze the expression of Bcl-2 as well as the survival of CA1 and CA3/DG pyramidal neurons. NS102, GSNO, sodium nitroprusside, and MG132 contribute to the survival of CA1 and CA3/DG pyramidal neurons by attenuating Bcl-2 denitrosylation. Taken together, our data reveal that Bcl-2 ubiquitin-dependent degradation is induced by Bcl-2 denitrosylation during neuronal apoptosis after KA treatment.
authors.affiliation: Research Center of Biochemistry and Molecular Biology, Jiangsu Province Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Yan
authors.forename: Yong-Ping
authors.initials: YP
authors.lastname: Wu
authors.forename: Chong
authors.initials: C
authors.lastname: Li
authors.forename: Guang-Yi
authors.initials: GY
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D056654:CA3 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D018891:Dentate Gyrus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004827:Epilepsy / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007608:Kainic Acid / Q000633:toxicity; D008297:Male; D009447:Neuroblastoma; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D011499:Protein Processing, Post-Translational / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018092:Kainic Acid Receptors / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism*; D000097806:GluK2 Kainate Receptor
chemical_list: D053148:Caspase 3; D018690:Excitatory Amino Acid Agonists; D007608:Kainic Acid; D009569:Nitric Oxide; D020030:Nitric Oxide Donors; D009584:Nitrogen; D046988:Proteasome Endopeptidase Complex; D061988:Proteasome Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D018092:Kainic Acid Receptors; D025801:Ubiquitin; D000097806:GluK2 Kainate Receptor; C505410:Casp3 protein, rat