Deletion of the kinase domain in death-associated protein kinase attenuates tubular cell apoptosis in renal ischemia-reperfusion injury

• Published in: Journal of the American Society of Nephrology 2004-07, Vol.15 (7), p.1826-1834
• Main Authors: KISHINO, Masanori, YUKAWA, Kazunori, ICHINOSE, Masakazu, TAKEDA, Kiyoshi, AKIRA, Shizuo, MUNE, Masatoshi, HOSHINO, Katsuaki, KIMURA, Akihiko, SHIRASAWA, Nobuyuki, OTANI, Haruhisa, TANAKA, Tetsuji, OWADA-MAKABE, Kyoko, TSUBOTA, Yuji, MAEDA, Masanobu
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Apoptosis Regulatory Proteins; Biological and medical sciences; Blotting, Western; Calcium-Calmodulin-Dependent Protein Kinases - chemistry; Calcium-Calmodulin-Dependent Protein Kinases - genetics; Caspase 3; Caspases - metabolism; Cell Nucleus - metabolism; Chromosome aberrations; Death-Associated Protein Kinases; Enzyme Activation; Gene Deletion; Homozygote; Immunohistochemistry; In Situ Nick-End Labeling; Kidney - metabolism; Kidney - pathology; Medical genetics; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Nephrology. Urinary tract diseases; Protein Structure, Tertiary; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Time Factors; Tumor Suppressor Protein p53 - metabolism
• ISSN: 1046-6673; 1533-3450
• DOI: 10.1097/01.asn.0000131527.59781.f2

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.