Expression of midkine and receptor-like protein tyrosine phosphatase (RPTP)-beta genes in the rat stomach and the influence of rebamipide.
BACKGROUND
Midkine has been reported to bind to receptor-like protein tyrosine phosphatase (RPTP)-beta and to play important roles in growth and differentiation of various cells. Midkine is expressed in rat stomach during experimental ulcer healing, suggesting that the midkine-RPTP-beta system has some physiological functions in the stomach. Rebamipide is a mucoprotective drug used for the treatment of gastric ulcers. We have tested the hypothesis that the ulcer healing mechanism stimulated by rebamipide is linked physiologically to the gastric midkine-RPTP-beta system.


METHODS
Seven-week-old-male Wistar rats were used. Midkine and RPTP-beta gene expression in rat stomach was investigated by laser capture microdissection coupled with the reverse transcription-polymerase chain reaction (RT-PCR). The effects of rebamipide on midkine and RPTP-beta expression in rat stomach and the gastric epithelial cell line RGM1 were evaluated by RT-PCR and Northern blot analyses.


RESULTS
Midkine and RPTP-beta expression was detected in the gastric mucosal, submucosal and muscle layers. Rebamipide stimulated both midkine and RPTP-beta expression in rat stomach and RGM1 cells.


CONCLUSIONS
Rebamipide may protect the gastric mucosa by regulating midkine and RPTP-beta expression.
Yuki
T
T
Department of Internal Medicine II, Shimane Medical University, Shimane, Japan.
Ishihara
S
S
Rumi
M
M
Ortega-Cava Cesar
F
F
Kadowaki
Y
Y
Kazumori
H
H
Yuki
M
M
Wada
T
T
Miyaoka
Y
Y
Yoshino
N
N
Kinoshita
Y
Y
D000409:Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D016207:Cytokines; D005753:Gastric Mucosa / Q000378:metabolism*; D008297:Male; D000078792:Midkine; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D015363:Quinolones / Q000494:pharmacology*; D012313:RNA / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D000897:Anti-Ulcer Agents; D002352:Carrier Proteins; D016207:Cytokines; D009419:Nerve Tissue Proteins; D015363:Quinolones; D000078792:Midkine; D012313:RNA; D017027:Protein Tyrosine Phosphatases; C516852:Ptprg protein, rat; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; C052785:rebamipide; D000409:Alanine