Skip to main content
ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Toxicology & Mycotoxin Research » Research » Publications at this Location » Publication #295156
Title: Increased nuclear sphingoid base-1-phosphates and HDAC inhibition after fumonisin and FTY720-treatment: the link between epigenomic modifications and neural tube defects?

Author
item GARDNER, NICOLE - National Institute Of Public Health (INSP)
item SACHS, ANDREW - Creighton University
item Riley, Ronald
item MADDOX, JOYCE - Creighton University
item GELINEAU-VAN WAES, JANEE - Creighton University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/7/2013
Publication Date: 10/7/2013
Citation: Gardner, N.M., Sachs, A.J., Riley, R.T., Maddox, J.R., Gelineau-Van Waes, J. 2013. Increased nuclear sphingoid base-1-phosphates and HDAC inhibition after fumonisin and FTY720-treatment: the link between epigenomic modifications and neural tube defects?. 8th International Conference on Neural Tube Defects. October 7, 2013. Austin, Texas.

Interpretive Summary: Abstract - no summary required.

Technical Abstract: Introduction: Fumonisin B1 (FB1) is a mycotoxin produced by a common fungal contaminant of corn. Ingestion of FB1-contaminated food during early pregnancy is associated with increased risk for neural tube defects (NTDs). FB1 inhibits the enzyme ceramide synthase in de novo sphingolipid biosynthesis, resulting in accumulation of bioactive sphinganine-1-phosphate (Sa1P). FTY720 is phosphorylated in vivo to produce bioactive FTY720-1-phosphate. Both FB1 and FTY720 have been shown to cause NTDs in inbred LM/Bc mice. Nuclear sphingoid base-1-phosphates have been shown to inhibit histone deacetylases (HDACs). Exposure to known HDAC inhibitors during pregnancy can cause NTDs. The purpose of this study was to determine if exposure to FB1 or FTY720 results in accumulation of nuclear Sa1P or FTY720-1-P, HDAC inhibition, and post translational modifications (PTMs) in core histones. Methods: Mouse neural progenitor (SFME) and LM/Bc and SWV mouse embryonic fibroblast (MEF) cells were cultured for three days and treated with vehicle control, 40 µM FB1 or 1 µM FTY720 for 24 hours. Cells were harvested and separated into nuclear and cytosolic fractions. Lipidomic analysis of sphingoid base-1-phosphates was performed by LC/MS. HDAC activity was measured using an HDAC Activity Assay (Cayman). Histones were isolated using a Histone Purification Mini Kit (Active Motif). Histone PTMs were evaluated using western blots and LC/LC/MS/MS. Pregnant LM/Bc dams were treated with vehicle or FB1 (20 mg/kg/day on E7.5-E9.5 via intraperitoneal injection). E9.5 embryos were paraffin-embedded and sectioned. Histone acetylation was evaluated using immunohistochemistry (IHC). Results: Sa1P or FTY720-P accumulated in the nucleus of SFME and MEF cells treated with FB1 or FTY720, and HDAC activity was decreased. After FB1 treatment, nuclear Sa1P was higher and HDAC activity was lower in LM/Bc compared to SWV MEFs. Increased acetylation of histones at H2BK12, H3K9, and H4K5 was detected by western blot and IHC. Additional histone PTMS were detected by LC/LC/MS/MS. Discussion: FB1 and FTY720-treatment results in increased nuclear sphingoid base-1-phosphates, HDAC inhibition, and increased acetylation of specific lysine residues in core histones. HDAC inhibition and epigenomic modifications after FB1 or FTY720 exposure may result in chromatin remodeling and altered expression of genes critical for proper neural tube closure.