title: Deletion of the kinase domain in death-associated protein kinase attenuates tubular cell apoptosis in renal ischemia-reperfusion injury.
abstract: Death-associated protein kinase (DAPK) is a calcium/calmodulin-dependent serine/threonine kinase localized to renal tubular epithelial cells. To elucidate the contribution of DAPK activity to apoptosis in renal ischemia-reperfusion (IR) injury, wild-type (WT) mice and DAPK-mutant mice, which express a DAPK deletion mutant that lacks a portion of the kinase domain, were subjected to renal pedicle clamping and reperfusion. After IR, DAPK activity was elevated in WT kidneys but not in mutant kidneys (1785.7 +/- 54.1 pmol/min/mg versus 160.7 +/- 60.6 pmol/min/mg). Furthermore, there were more TUNEL-positive nuclei and activated caspase 3-positive cells in WT kidneys than in mutant kidneys after IR (24.0 +/- 5.9 nuclei or 9.4 +/- 0.6 cells per high-power field [HPF] versus 6.3 +/- 2.2 nuclei or 4.4 +/- 0.7 cells/HPF at 40 h after ischemia). In addition, the increase in p53-positive tubule cells after IR was greater in WT kidney than in mutant kidneys (9.9 +/- 1.4 cells/HPF versus 0.8 +/- 0.4 cells/HPF), which is consistent with the theory that DAPK activity stabilizes p53 protein. Finally, serum creatinine levels after IR were higher in WT mice than in mutant mice (2.54 +/- 0.34 mg/dl versus 0.87 +/- 0.24 mg/dl at 40 h after ischemia). Thus, these results indicate that deletion of the kinase domain from DAPK molecule can attenuate tubular cell apoptosis and renal dysfunction after IR injury.
authors.affiliation: Department of Internal Medicine, Wakayama Medical University, Wakayama, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Kishino
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yukawa
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Hoshino
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kimura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shirasawa
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Otani
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kyoko
authors.initials: K
authors.lastname: Owada-Makabe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tsubota
authors.forename: Masanobu
authors.initials: M
authors.lastname: Maeda
authors.forename: Masakazu
authors.initials: M
authors.lastname: Ichinose
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Takeda
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Mune
mesh_terms: D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000235:genetics*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D064550:Death-Associated Protein Kinases; D004789:Enzyme Activation; D017353:Gene Deletion; D006720:Homozygote; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007668:Kidney / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009154:Mutation; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D015427:Reperfusion Injury; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases