Lysophosphatidic Acid Produced by Hen Egg White Lysophospholipase D Induces Vascular Development on Extraembryonic Membranes

Abstract

Lysophosphatidic acid (lysoPtdOH), a lysophospholipid mediator, exerts diverse physiological effects, including angiogenesis, through its specific G-protein-coupled receptors. Previously, we showed that unfertilized hen egg white contains polyunsaturated fatty acid-rich lysoPtdOH and lysophospholipase D (lysoPLD). Here, we examined whether lysoPtdOH was produced by lysoPLD in the presence and absence of a hen fertilized ovum and what the physiological role of lysoPtdOH in hen egg white is. Mass spectrometry showed that fertilized hen egg white contained about 8 μM lysoPtdOH before incubation with an ovum, mainly comprised of 18:1- (12.6 %), 18:2- (37.8 %) and 20:4-molecular species (41.5 %). In an early gestation period, the lysoPtdOH was increased up to 9.6 μM, concomitant with a decrease in the level of polyunsaturated lysophosphatidylcholine (lysoPtdCho). Moreover, lysoPtdOH-degrading activities were found in egg white and the vitelline membrane, showing that these enzymes control lysoPtdOH levels in egg white. In an egg yolk angiogenesis assay, two lysoPtdOH receptor antagonists, Ki16425 and N-palmitoyl serine phosphoric acid (NASP), inhibited blood vessel formation induced by exogenously added 18:1-lysoPtdOH and its precursor lysoPtdCho on the hen yolk sac. Ki16425 and NASP also inhibited blood vessel formation in the chorioallantoic membrane (CAM). Furthermore, the relatively higher levels of LPA₁, LPA₂, LPA₄ and LPA₆ mRNA were present in the yolk sac and CAM. These results suggest that lysoPtdOH produced from lysoPtdCho by the action of lysoPLD in hen egg white is involved in the formation of blood vessel networks through several lysoPtdOH receptors on various extraembryonic membranes, including the yolk sac membrane and CAM.

Discovery of Spoilage Markers for Chicken Eggs Using Liquid Chromatography-High Resolution Mass Spectrometry-Based Untargeted and Targeted Foodomics

“…44 Second, when the quality of eggs declines over time, the vitelline membrane becomes fragile and loses its strength. The endogenous enzyme originating in the albumen, lysophospholipase D, for instance, 45 may enter the yolk and catalyze the cleavage of phospholipids. Hence, this phospholipid catabolism can be initiated by phospholipases from microbes or the egg itself.…”

Uji Efektivitas Putih Telur Ayam Kampung (Gallus domesticus) Terhadap Penyembuhan Luka Bakar Derajat II pada Mencit (Mus musculus)

“…26 Penelitian yang dilakukan oleh Morishije pada tahun 2013 dalam penelitiannya mengungkapkan bahwa lysophospatidic acid yang terdapat pada putih telur yang tidak dibuahi dapat menginduksi perkembangan pembentukan pembuluh darah. 27 Putih telur mengandung sejumlah protein yang dapat memicu faktor pertumbuhan. Protein albumin yang terkandung dalam putih telur memiliki sifat terapeutik dan imunogenik.…”

Evaluation of the in vivo antioxidative activity of redox nanoparticles by using a developing chicken egg as an alternative animal model

“…Thus, the in vivo activity reflecting the pharmacokinetics of candidate compounds may be evaluable using this developing chicken egg model [11]. We have already succeeded in evaluating the in vivo activity of an antiangiogenic agent and a radiosensitizing agent by using this model [12][13][14][15].…”