1. Carboxyl ester lipase is highly conserved in utilizing maternal supplied lipids during early development of zebrafish and human.
- Author
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Qiu Y, Sun S, Yu X, Zhou J, Cai W, and Qian L
- Subjects
- Animals, Animals, Genetically Modified, Carboxylesterase genetics, Central Nervous System embryology, Cholesterol metabolism, Cholesterol Esters metabolism, Disease Models, Animal, Embryo, Nonmammalian, Embryonic Development, Gene Knockdown Techniques, Growth Disorders embryology, Growth Disorders enzymology, Hedgehog Proteins metabolism, Humans, Lipid Metabolism, Morpholinos administration & dosage, Morpholinos genetics, Pancreas, Exocrine embryology, Pancreas, Exocrine enzymology, Triglycerides metabolism, Yolk Sac embryology, Zebrafish genetics, Zebrafish metabolism, Zebrafish Proteins genetics, Carboxylesterase metabolism, Gene Expression Regulation, Developmental, Growth Disorders genetics, Yolk Sac enzymology, Zebrafish embryology, Zebrafish Proteins metabolism
- Abstract
Carboxyl ester lipase (Cel), is a lipolytic enzyme secreted by the pancreas, which hydrolyzes various species of lipids in the gut. Cel is also secreted by mammary gland during lactation and exists in breast milk. It facilitates dietary fat digestion and absorption, thus contributing to normal infant development. This study aimed to examine whether the Cel in zebrafish embryos has a similar role of maternal lipid utilization as in human infants, and how Cel contributes to the utilization of yolk lipids in zebrafish. The cel1 and cel2 genes were expressed ubiquitously in the blastodisc and yolk syncytial layer before 24 hpf, and in the exocrine pancreas after 72 hpf. The cel1 and cel2 morphants exhibited developmental retardation and yolk sac retention. The total cholesterol, cholesterol ester, free cholesterol, and triglyceride were reduced in the morphants' body while accumulated in the yolk (except triglyceride). The FFA content of whole embryos was much lower in morphants than in standard controls. Moreover, the delayed development in cel (cel1/cel2) double morphants was partially rescued by FFA and cholesterol supplementation. Delayed and weakened cholesterol ester transport to the brain and eyes was observed in cel morphants. Correspondingly, shrunken midbrain tectum, microphthalmia, pigmentation-delayed eyes as well as down-regulated Shh target genes were observed in the CNS of double morphants. Interestingly, cholesterol injections reversed these CNS alterations. Our findings suggested that cel genes participate in the lipid releasing from yolk sac to developing body, thereby contributing to the normal growth rate and CNS development in zebrafish., Competing Interests: Declaration of competing interest Authors have declared no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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