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Ceramide inhibits development and cytokinesis and induces apoptosis in preimplantation bovine embryos
Author(s) -
Luiz Augusto de Castro e Paula,
Hansen Peter J.
Publication year - 2008
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.20841
Subject(s) - ceramide , biology , microbiology and biotechnology , lipid signaling , apoptosis , cytokinesis , sphingomyelin , embryo , immunology , endocrinology , cell , cell division , biochemistry , cholesterol , inflammation
Ceramide is a second messenger induced by various cellular insults that plays a regulatory role in apoptosis. The objective of the present study was to determine whether ceramide signaling can occur in the preimplantation embryo by testing (1) effects of ceramide on development, cytokinesis, and apoptosis and (2) whether heat shock, which can induce apoptosis in embryos, causes activation of neutral or acidic sphingomyelinases responsible for generation of ceramide. Treatment of embryos ≥16 cells collected at Day 5 after insemination with 50 µM C(2)‐ceramide increased caspase‐9 activity and the proportion of blastomeres undergoing apoptosis but did not increase caspase‐8 activity. Induction of apoptosis was more extensive when culture with ceramide was for 24 hr than for 9 hr. Ceramide also reduced the proportion of embryos that developed to the blastocyst stage when exposure was for 24 hr. At the two‐cell stage, a period in development when apoptosis responses are blocked, culture of embryos with ceramide did not increase caspase‐9 activity or the proportion of blastomeres that were apoptotic. However, culture with ceramide for 24 hr reduced cell proliferation and caused an increase in multinucleated cells because of inhibition of cytokinesis. Exposure of Day 5 embryos to a heat shock of 41°C for 15 hr increased neutral sphingomyelinase activity but did not change acid sphingomyelinase activity. In conclusion, ceramide can regulate embryo development and apoptosis in a time and stage‐of‐development dependent manner and ceramide generation can be activated by cellular insult. Thus, the ceramide signaling pathway is present in the preimplantation embryo. Mol. Reprod. Dev. 75: 1063–1070, 2007. © 2007 Wiley‐Liss, Inc.