Role of the LPA2 Receptor in Protecting Against Apoptosis
type: CreativeWork
description: Lysophosphatidic acid (LPA) is a naturally occurring lipid mediator. It exists abundantly in biological fluids such as serum, saliva, follicular fluid, seminal fluid and malignant effusions and induces a vast array of biological responses affecting cell growth, survival, differentiation, migration and morphology. We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. Based on computational modeling octadecenyl thiophosphate (OTP) was synthesized: a novel rationally designed, metabolically stabilized LPA mimic. OTP was more efficacious than LPA in reducing g-irradiation-, camptothecin-, or TNF-a/cycloheximide-induced apoptosis and caspase 3, 8 and 9 activity in the IEC-6 cell line. The OTP- and LPA-elicited antiapoptotic effects were completely blocked by the MEK inhibitor PD98059 and the PI3K inhibitor LY294002. Pertussis toxin partially abolished OTP-induced ERK1/2 and apoptotic protection. In RH7777 cells lacking LPA receptors, OTP selectively protected LPA2 but not LPA1 and LPA3 transfectants. In C57BL/6 and LPA1 knockout mice exposed to 15 Gy g-irradiation, orally applied OTP reduced the number of apoptotic bodies and activated caspase 3 positive cells but was ineffective in LPA2 knockouts. OTP, with higher efficacy than LPA, enhanced intestinal crypt survival in C57BL/6 mice but had no effect in LPA2 knockouts. Intraperitonealy administered OTP reduced death caused by LD100/30 radiation by 50%. Our data indicate that OTP is a highly effective antiapoptotic agent that engages similar prosurvival pathways to LPA through the LPA2 receptor subtype. Unique sequence motifs in the LPA2 carboxyl-terminal (CT) enable it to form macromolecular complexes with PDZ and LIM domain proteins, which link it to G protein-independent signaling networks. Using deletion and site-specific mutagenesis, we mapped out C311xxC314 motif of LPA2-CT that is required for interaction with LIM domain proteins thyroid hormone receptor…
abstract: Lysophosphatidic acid (LPA) is a naturally occurring lipid mediator. It exists abundantly in biological fluids such as serum, saliva, follicular fluid, seminal fluid and malignant effusions and induces a vast array of biological responses affecting cell growth, survival, differentiation, migration and morphology. We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. Based on computational modeling octadecenyl thiophosphate (OTP) was synthesized: a novel rationally designed, metabolically stabilized LPA mimic. OTP was more efficacious than LPA in reducing g-irradiation-, camptothecin-, or TNF-a/cycloheximide-induced apoptosis and caspase 3, 8 and 9 activity in the IEC-6 cell line. The OTP- and LPA-elicited antiapoptotic effects were completely blocked by the MEK inhibitor PD98059 and the PI3K inhibitor LY294002. Pertussis toxin partially abolished OTP-induced ERK1/2 and apoptotic protection. In RH7777 cells lacking LPA receptors, OTP selectively protected LPA2 but not LPA1 and LPA3 transfectants. In C57BL/6 and LPA1 knockout mice exposed to 15 Gy g-irradiation, orally applied OTP reduced the number of apoptotic bodies and activated caspase 3 positive cells but was ineffective in LPA2 knockouts. OTP, with higher efficacy than LPA, enhanced intestinal crypt survival in C57BL/6 mice but had no effect in LPA2 knockouts. Intraperitonealy administered OTP reduced death caused by LD100/30 radiation by 50%. Our data indicate that OTP is a highly effective antiapoptotic agent that engages similar prosurvival pathways to LPA through the LPA2 receptor subtype. Unique sequence motifs in the LPA2 carboxyl-terminal (CT) enable it to form macromolecular complexes with PDZ and LIM domain proteins, which link it to G protein-independent signaling networks. Using deletion and site-specific mutagenesis, we mapped out C311xxC314 motif of LPA2-CT that is required for interaction with LIM domain proteins thyroid hormone receptor…
author: E, Shuyu
keywords: LPA, LPA2 receptor, apoptosis, irradiation, protein-protein interaction, LIM domain PDZ domain, Medical Physiology, Medical Sciences, Medicine and Health Sciences
date published: 2008-12-01T08:00:00Z
date modified: 2026-07-24T05:00:23Z
provider: University of Tennessee Health Science Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Tennessee Health Science Center