The Phosphorylation State of GSK3β Serine 9 Correlated to the Development of Valproic Acid-Associated Fetal Cardiac Teratogenicity, Fetal VPA Syndrome, Rescued by Folic Acid Administration.
The effects of the phosphorylation state of the glycogen synthase kinase 3β involved in the cardiac myocytes (jelly-like cells) epithelial-mesenchymal transition-associated migration during heart-valve formation were examined through the valproic acid-induced cardiac teratogenicity of transgenic line A34 of Tg in a the Brachydanio rerio embryo model. Valproic acid is an effective anti-epileptic drug; however, when taken by pregnant women to treat epilepsy, it can produce cardiac developmental defects in fetuses. In this study, the role of glycogen synthase kinase 3β in valproic acid-induced cardiac teratogenicity was investigated. Transgenic line A34 of zebrafish embryos was used at 3 days postfertilization. The results show that 78% (18/23) of the embryos treated with 0.10 mM valproic acid (group A) had incomplete chamber formation with normal looping and 22 % (5/23) had abnormal looping. Bradycardia was also found in comparison with control embryos (P < 0.001). For the embryos treated with 0.25 mM valproic acid (group B), 92% (22/24) demonstrated chamber formation failure and looping abnormality. Pericardial effusion, noncontracting ventricles, and enlarged, slowly beating atriums were observed at 6 days postfertilization. Valproic acid inhibited phosphorylation of serine 9 in glycogen synthase kinase 3β in a dose-dependent manner. According to immunochemical staining results, valproic acid was shown to inhibit the mass migration and proliferation of cardiomyocytes in the development of the heart-valve region through inhibition of the GSK3β Ser 9 phosphorylation. Folic acid rescued the GSK3β Ser 9 phosphorylation and reversed the valproic acid-induced cardiac morphological, functional, and biochemical defects.
Institute of Biochemistry and Molecular Biology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. whyu2004@ntu.edu.tw.|Department of Biochemistry and Molecular Biology, Graduate Institute of Brain and Mind Sciences, National Taiwan University Hospital and National Taiwan University College of Medicine, Room 0946, No 1, Sec 1, Jan-Ai Road, Taipei, 100, Taiwan. whyu2004@ntu.edu.tw.
Wei-Hsuan
WH
Yu
Graduate Institute of Clinical Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.|Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Yi-Lwun
YL
Ho
Institute of Biochemistry and Molecular Biology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Po-Tsang
PT
Huang
Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.
Shian-Ling
SL
Chu
Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.
Huai-Jen
HJ
Tsai
Department of Pharmacology and Neurology, National Taiwan University Hospital and National Taiwan University College of Medicine, No 7, Chung-Shan South Road, Taipei, 100, Taiwan. hhl@ntu.edu.tw.
Horng-Huei
HH
Liou
D000818:Animals; D030801:Animals, Genetically Modified; D000927:Anticonvulsants / Q000633:toxicity*; D001919:Bradycardia / Q000139:chemically induced / Q000151:congenital; D049109:Cell Proliferation; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D038362:Glycogen Synthase Kinase 3 / Q000187:drug effects* / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006330:Heart Defects, Congenital / Q000139:chemically induced* / Q000517:prevention & control*; D006352:Heart Ventricles / Q000002:abnormalities / Q000473:pathology; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism*; D014635:Valproic Acid / Q000633:toxicity*; D014815:Vitamins / Q000627:therapeutic use*; D015027:Zebrafish
D000927:Anticonvulsants; D014815:Vitamins; D012694:Serine; D014635:Valproic Acid; D005492:Folic Acid; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3
Epithelial–mesenchymal transition (EMT); GSK3β; Heart valve; Teratogenicity; Valproic acid