title: Procaspase-9 induces its cleavage by transnitrosylating XIAP via the Thioredoxin system during cerebral ischemia-reperfusion in rats.
abstract: Transnitrosylation is an important mechanism by which nitric oxide (NO) modulates cell signaling pathways. For instance, SNO-caspase-3 can transnitrosylate the X-linked inhibitor of apoptosis (XIAP) to enhance apoptosis. XIAP is a potent antagonist of caspase apoptotic activity. Decrease in XIAP activity via nitrosylation results in SNO-XIAP-mediated caspase activation. Considering the functional liaison of procaspase-9 and XIAP, we hypothesized that procaspase-9 nitrosylates XIAP directly. Our data confirmed that cerebral ischemia-reperfusion induced XIAP nitrosylation, procaspase-9 denitrosylation and cleavage. Interestingly, the time courses of the nitrosylation of procaspase-9 and XIAP were negatively correlated, which was more prominent after cerebral ischemia-reperfusion, suggesting a direct interaction. The nitrosylation of XIAP, as well as the denitrosylation and cleavage of procaspase-9, were inhibited by DNCB, TrxR1 AS-ODNs, or TAT-AVPY treatment. Meanwhile, DNCB, TrxR1 AS-ODNs, or TAT-AVPY also inhibited the decrease in hippocampal CA1 neurons induced by ischemia-reperfusion in rats. The denitrosylation and cleavage of procaspase-9 induced by OGD/reoxygenation in SH-SY5Y cells were inhibited when cells were co-transfected with wild-type procaspase-9 and XIAP mutant (C449G). These data suggest that cerebral ischemia-reperfusion induces a transnitrosylation from procaspase-9 to XIAP via the Trx system to consequently cause apoptosis. Additionally, Cys325 is a critical S-nitrosylation site of procaspase-9.
authors.affiliation: Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou 221004, China.
authors.forename: Dengyue
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.|Emergency Center of the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Ningjun
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Xuzhou 221004, China.|Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
authors.affiliation: Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physiology, College of Basic Medical Science, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China.
authors.forename: Gongliang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.|Emergency Center of the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Xianliang
authors.initials: X
authors.lastname: Yan
authors.affiliation: Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.|Emergency Center of the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Shuqun
authors.initials: S
authors.lastname: Hu
authors.affiliation: Institute of Emergency Rescue Medicine, Xuzhou Medical College, Xuzhou 221002, China.|Emergency Center of the Affiliated Hospital of Xuzhou Medical College, Xuzhou 221002, China.
authors.forename: Tie
authors.initials: T
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015153:Blotting, Western; D002545:Brain Ischemia / Q000235:genetics / Q000378:metabolism*; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004137:Dinitrochlorobenzene / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009154:Mutation; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D011485:Protein Binding / Q000235:genetics; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000235:genetics / Q000378:metabolism*; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*
chemical_list: D004137:Dinitrochlorobenzene; D051034:Inhibitor of Apoptosis Proteins; D016376:Oligonucleotides, Antisense; D010455:Peptides; C494837:Xiap protein, rat; D009569:Nitric Oxide; D013879:Thioredoxins; D053453:Caspase 9