The lysophosphatidic acid type 2 receptor is required for protection against radiation-induced intestinal injury.
Gastroenterology
; 132(5): 1834-51, 2007 May.
Article
em En
| MEDLINE
| ID: mdl-17484878
ABSTRACT
BACKGROUND & AIMS:
We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. The objective of the present study was to evaluate the effect of octadecenyl thiophosphate (OTP), a novel rationally designed, metabolically stabilized LPA mimic, on radiation-induced apoptosis of intestinal epithelial cells in vitro and in vivo.METHODS:
The receptors and signaling pathways activated by OTP were examined in IEC-6 and RH7777 cell lines and wild-type and LPA(1) and LPA(2) knockout mice exposed to different apoptotic stimuli.RESULTS:
OTP was more efficacious than LPA in reducing gamma irradiation-, camptothecin-, or tumor necrosis factor alpha/cycloheximide-induced apoptosis and caspase-3-8, and caspase-9 activity in the IEC-6 cell line. In RH7777 cells lacking LPA receptors, OTP selectively protected LPA(2) but not LPA(1) and LPA(3) transfectants. In C57BL/6 and LPA(1) knockout mice exposed to 15 Gy gamma irradiation, orally applied OTP reduced the number of apoptotic bodies and activated caspase-3-positive cells but was ineffective in LPA(2) knockout mice. OTP, with higher efficacy than LPA, enhanced intestinal crypt survival in C57BL/6 mice but was without any effect in LPA(2) knockout mice. Intraperitoneally administered OTP reduced death caused by lethal dose (LD)(100/30) radiation by 50%.CONCLUSIONS:
Our data indicate that OTP is a highly effective antiapoptotic agent that engages similar prosurvival pathways to LPA through the LPA(2) receptor subtype.
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Base de dados:
MEDLINE
Assunto principal:
Compostos Organofosforados
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Lesões Experimentais por Radiação
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Apoptose
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Receptores de Ácidos Lisofosfatídicos
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Mucosa Intestinal
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article