The kinase domain of death-associated protein kinase is inhibitory for tubulointerstitial fibrosis in chronic obstructive nephropathy.
Death-associated protein kinase (DAPK) is a Ca2+/calmodulin-dependent serine/threonine kinase that is thought to mediate apoptosis. We have shown that the kinase domain of DAPK is crucial for the induction of renal tubular cell apoptosis in chronic obstructive uropathy (COU) created by unilateral ureteral ligation. DAPK-mutant mice, generated by deletion of 74 amino acids from the catalytic kinase domain, were used to investigate the role of the DAPK kinase domain in renal fibrosis following COU. Interstitial collagen and alpha-smooth muscle actin (alpha-SMA) expressions in situ were compared between obstructed kidneys in wild-type and mutant mice. As a result, tubulointerstitial fibrosis, as quantified by interstitial collagen expression, was significantly augmented in mutant kidneys compared with wild-type kidneys following COU. Furthermore, deletion of the kinase domain from DAPK significantly increased the appearance of alpha-SMA-positive myofibroblasts in the renal interstitium during COU. Thus, our results suggest that the kinase domain deleted by gene targeting plays a suppressive role for the development of renal fibrosis through inhibition of the tubular epithelial-to-mesenchymal transition in a mouse model of COU.
Yukawa
Kazunori
K
Department of Physiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8509, Japan. kazu59@wakayama-med.ac.jp
Kishino
Masanori
M
Hoshino
Katsuaki
K
Shirasawa
Nobuyuki
N
Kimura
Akihiko
A
Tsubota
Yuji
Y
Owada-Makabe
Kyoko
K
Bai
Tao
T
Tanaka
Tetsuji
T
Ueyama
Takashi
T
Ichinose
Masakazu
M
Takeda
Kiyoshi
K
Akira
Shizuo
S
Maeda
Masanobu
M
D000199:Actins / Q000378:metabolism; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D024042:Collagen Type I / Q000378:metabolism; D064550:Death-Associated Protein Kinases; D005355:Fibrosis / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D051379:Mice; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D014517:Ureteral Obstruction / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
D000199:Actins; D051017:Apoptosis Regulatory Proteins; D024042:Collagen Type I; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases