Fetal ethanol exposure activates protein kinase a and impairsShh expression in prechordal mesendoderm cells in the pathogenesis of holoprosencephaly
| Autor: | Kazushi Aoto, Daisuke Higashiyama, Yayoi Shikata, Jun Motoyama, Kohei Shiota |
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| Rok vydání: | 2008 |
| Předmět: |
Telencephalon
Embryology medicine.medical_specialty animal structures Notochord Apoptosis Endogeny Ascorbic Acid medicine.disease_cause Models Biological Pathogenesis Mice Holoprosencephaly Pregnancy Internal medicine medicine Animals Vitamin E Hedgehog Proteins Sonic hedgehog Protein kinase A Cells Cultured Fetus Ethanol biology Endoderm Gene Expression Regulation Developmental General Medicine medicine.disease Cyclic AMP-Dependent Protein Kinases Mice Inbred C57BL Endocrinology Maternal Exposure Face Maternal-Fetal Relations embryonic structures Pediatrics Perinatology and Child Health biology.protein Female Oxidative stress Developmental Biology |
| Zdroj: | Birth Defects Research Part A: Clinical and Molecular Teratology. 82:224-231 |
| ISSN: | 1542-0760 1542-0752 |
| DOI: | 10.1002/bdra.20447 |
| Popis: | BACKGROUND: In humans, fetal ethanol exposure can cause holoprosencephaly (HPE), one of the most common birth defects that is characterized by brain, facial, and oral abnormalities. However, the pathogenesis of HPE is not clear. In the present study, we investigated the teratogenic mechanism of ethanol-induced brain and facial malformations in mice. METHODS: Pregnant C57BL/6J mice were administered ethanol on E7 and facial and brain malformations were characterized on E10.5. We examined the effect of fetal ethanol exposure on Shh expression and activation of protein kinase A (PKA) because mutations in the human Shh gene are the most frequent cause of autosomal-dominant inherited HPE and PKA is a potent endogenous antagonist of Shh signaling. RESULTS: Fetal ethanol exposure on E7 induced severe midline defects characteristic of HPE. Ethanol exposure impaired Shh expression and induced excessive apoptosis only along the anterior edge of the prechordal mesendoderm (PME). In addition, ethanol activated PKA in anterior PME cells. Pretreatment of embryos with antioxidants, such as vitamins C or E, prevented the development of ethanol-induced HPE. CONCLUSIONS: Shh expression in PME cells is involved in the pathogenesis of ethanol-induced HPE. Ethanol may impair Shh expression indirectly by activating PKA. The inhibition of excessive apoptosis in PME cells by antioxidants implies that oxidative stress may underlie the teratogenic actions of ethanol. Thus, antioxidant treatment may be a simple preventative measure that could reduce the incidence of HPE following fetal ethanol exposure. Birth Defects Research (Part A), 2008. © 2008 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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