Oxidative stress decreases klotho expression in a mouse kidney cell line.
OBJECTIVE
Defects in klotho gene expression in the mouse result in a syndrome that resembles human aging. We recently identified expression of klotho in a mouse inner medullary collecting duct (mIMCD3) cell line for the first time, and in the present study we explored the physiological relevance of the regulation of klotho expression in the presence of oxidant stress injury.


METHODS
Klotho expression was analyzed by real-time PCR, Western blot, and immuocytochemical staining during exposure to hydrogen peroxide (H2O2). Overexpression of the klotho gene was induced by klotho adenoviruses, and the number of apoptotic cells was counted by flowcytometry.


RESULTS
Oxidant stress injury by H2O2 dose-dependently reduced klotho expression and diminished klotho staining. There were fewer apoptotic cells among the klotho-transfected cells than among the control cells.


CONCLUSIONS
Klotho is expressed in cell line mIMCD3, and the klotho gene may be involved in the process of oxidative stress injury and apoptosis in this cell line.
Department of Medicine IV, Tokyo Women's Medical University, Tokyo, Japan.
Michihiro
M
Mitobe
Takumi
T
Yoshida
Hidekazu
H
Sugiura
Satsuki
S
Shirota
Ken
K
Tsuchiya
Hiroshi
H
Nihei
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D015153:Blotting, Western; D002460:Cell Line; D003199:Computer Systems; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D005966:Glucuronidase; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology; D007150:Immunohistochemistry / Q000379:methods; D007679:Kidney Medulla; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D000090265:Klotho Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D016877:Oxidants / Q000008:administration & dosage / Q000494:pharmacology; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013194:Staining and Labeling
D008565:Membrane Proteins; D016877:Oxidants; D006861:Hydrogen Peroxide; D005966:Glucuronidase; D000090265:Klotho Proteins