title: Autophagy is involved in ethanol-induced cardia bifida during chick cardiogenesis.
abstract: Excess alcohol consumption during pregnancy has been acknowledged to increase the incidence of congenital disorders, especially the cardiovascular system. However, the mechanism involved in ethanol-induced cardiac malformation in prenatal fetus is still unknown. We demonstrated that ethanol exposure during gastrulation in the chick embryo increased the incidence of cardia bifida. Previously, we reported that autophagy was involved in heart tube formation. In this context, we demonstrated that ethanol exposure increased ATG7 and LC3 expression. mTOR was found to be inhibited by ethanol exposure. We activated autophagy using exogenous rapamycin (RAPA) and observed that it induced cardiac bifida and increased GATA5 expression. RAPA beads implantation experiments revealed that RAPA restricted ventricular myosin heavy chain (VMHC) expression. In vitro explant cultures of anterior primitive streak demonstrated that both ethanol and RAPA treatments could reduce cell differentiation and the spontaneous beating of cardiac precursor cells. In addition, the bead experiments showed that RAPA inhibited GATA5 expression during heart tube formation. Semiquantitative RT-PCR analysis indicated that BMP2 expression was increased while GATA4 expression was suppressed. In the embryos exposed to excess ethanol, BMP2, GATA4 and FGF8 expression was repressed. These genes are associated with cardiomyocyte differentiation, while heart tube fusion is associated with increased Wnt3a but reduced VEGF and Slit2 expression. Furthermore, the ethanol exposure also caused the production of excess ROS, which might damage the cardiac precursor cells of developing embryos. In sum, our results revealed that disrupting autophagy and excess ROS generation are responsible for inducing abnormal cardiogenesis in ethanol-treated chick embryos.
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Shuai
authors: S
authors: Li
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Guang
authors: G
authors: Wang
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Lin-Rui
authors: LR
authors: Gao
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Wen-Hui
authors: WH
authors: Lu
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Xiao-Yu
authors: XY
authors: Wang
authors: b Division of Cell and Developmental Biology ; University of Dundee ; Dundee , UK.
authors: Manli
authors: M
authors: Chuai
authors: d Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Biomedical Sciences, Chinese University of Hong Kong ; Shatin , Hong Kong.
authors: Kenneth Ka Ho
authors: KK
authors: Lee
authors: c Key Laboratory of Medical Cell Biology, China Medical University ; Shenyang , China.
authors: Liu
authors: L
authors: Cao
authors: a Division of Histology and Embryology ; Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University ; Guangzhou , China.
authors: Xuesong
authors: X
authors: Yang
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects* / Q000502:physiology; D002642:Chick Embryo; D000431:Ethanol / Q000633:toxicity*; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000196:embryology*; D006330:Heart Defects, Congenital / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D038081:Organogenesis / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D000431:Ethanol
keywords: autophagy; cardia bifida; chick embryo; ethanol; heart tube