Inhibitors of choline uptake and metabolism cause developmental abnormalities in neurulating mouse embryos.
BACKGROUND
Choline is an essential nutrient in methylation, acetylcholine and phospholipid biosynthesis, and in cell signaling. The demand by an embryo or fetus for choline may place a pregnant woman and, subsequently, the developing conceptus at risk for choline deficiency.


METHODS
To determine whether a disruption in choline uptake and metabolism results in developmental abnormalities, early somite staged mouse embryos were exposed in vitro to either an inhibitor of choline uptake and metabolism, 2-dimethylaminoethanol (DMAE), or an inhibitor of phosphatidylcholine synthesis, 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH(3)). Cell death following inhibitor exposure was investigated with LysoTracker Red and histology.


RESULTS
Embryos exposed to 250-750 microM DMAE for 26 hr developed craniofacial hypoplasia and open neural tube defects in the forebrain, midbrain, and hindbrain regions. Embryos exposed to 125-275 microM ET-18-OCH(3) exhibited similar defects or expansion of the brain vesicles. ET-18-OCH(3)-affected embryos also had a distended neural tube at the posterior neuropore. Embryonic growth was reduced in embryos treated with either DMAE (375, 500, and 750 microM) or ET-18-OCH(3) (200 and 275 microM). Whole mount staining with LysoTracker Red and histological sections showed increased areas of cell death in embryos treated with 275 microM ET-18-OCH(3) for 6 hr, but there was no evidence of cell death in DMAE-exposed embryos.


CONCLUSIONS
Inhibition of choline uptake and metabolism during neurulation results in growth retardation and developmental defects that affect the neural tube and face.
Fisher
M C
MC
Department of Cell Biology and Anatomy, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
Zeisel
S H
SH
Mar
M H
MH
Sadler
T W
TW
D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D000818:Animals; D018726:Anti-Dyskinesia Agents / Q000633:toxicity*; D002794:Choline / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D003642:Deanol / Q000633:toxicity*; D004622:Embryo, Mammalian / Q000187:drug effects* / Q000473:pathology; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D005260:Female; D008297:Male; D051379:Mice; D009436:Neural Tube Defects / Q000139:chemically induced* / Q000196:embryology / Q000473:pathology; D009924:Organ Culture Techniques; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology / Q000633:toxicity; D010742:Phospholipid Ethers / Q000494:pharmacology / Q000633:toxicity; D011247:Pregnancy
D018726:Anti-Dyskinesia Agents; D010726:Phosphodiesterase Inhibitors; D010742:Phospholipid Ethers; C026659:edelfosine; D003642:Deanol; D002794:Choline