LPA4 regulates blood and lymphatic vessel formation during mouse embryogenesis.
Lysophosphatidic acid (LPA) is a potent lipid mediator with a wide variety of biological actions mediated through G protein-coupled receptors (LPA(1-6)). LPA(4) has been identified as a G(13) protein-coupled receptor, but its physiological role is unknown. Here we show that a subset of LPA(4)-deficient embryos did not survive gestation and displayed hemorrhages and/or edema in many organs at multiple embryonic stages. The blood vessels of bleeding LPA(4)-deficient embryos were often dilated. The recruitment of mural cells, namely smooth muscle cells and pericytes, was impaired. Consistently, Matrigel plug assays showed decreased mural cell coverage of endothelial cells in the neovessels of LPA(4)-deficient adult mice. In situ hybridization detected Lpa4 mRNA in the endothelium of some vasculatures. Similarly, the lymphatic vessels of edematous embryos were dilated. These results suggest that LPA(4) regulates establishment of the structure and function of blood and lymphatic vessels during mouse embryogenesis. Considering the critical role of autotaxin (an enzyme involved in LPA production) and Gα(13) in vascular development, we suggest that LPA(4) provides a link between these 2 molecules.
Sumida
Hayakazu
H
Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
Noguchi
Kyoko
K
Kihara
Yasuyuki
Y
Abe
Manabu
M
Yanagida
Keisuke
K
Hamano
Fumie
F
Sato
Shinichi
S
Tamaki
Kunihiko
K
Morishita
Yasuyuki
Y
Kano
Mitsunobu R
MR
Iwata
Caname
C
Miyazono
Kohei
K
Sakimura
Kenji
K
Shimizu
Takao
T
Ishii
Satoshi
S
D000818:Animals; D001808:Blood Vessels / Q000196:embryology* / Q000378:metabolism; D015152:Blotting, Northern; D015139:Blotting, Southern; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D042601:Lymphatic Vessels / Q000196:embryology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011983:Receptors, Purinergic / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D049368:Receptors, Lysophosphatidic Acid
D011983:Receptors, Purinergic; C523574:Lpar4 protein, mouse; D049368:Receptors, Lysophosphatidic Acid