Main content area

A blood spot method for detecting fumonisin-induced changes in putative sphingolipid biomarkers in LM/Bc mice and humans

Riley, Ronald T., Showker, Jency L., Lee, Christine M., Zipperer, Cody E., Mitchell, Trevor R., Voss, Kenneth A., Zitomer, Nicholas C., Torres, Olga, Matute, Jorge, Gregory, Simon G., Ashley-Koch, Allison E., Maddox, Joyce R., Gardner, Nicole, Gelineau-Van Waes, Janee B.
Food additives & contaminants 2015 v.32 no.6 pp. 934-949
absorbance, animal models, biomarkers, blood, blood volume, ceramides, corn, formic acid, fumonisins, half life, humans, males, mice, neural tube defects, paper, protein content, risk factors, tissues, urine
Fumonisins (FB) are mycotoxins found in maize. They are hypothesised risk factors for neural tube defects (NTDs) in humans living where maize is a dietary staple. In LM/Bc mice, FB ₁-treatment of pregnant dams induces NTDs and results in increased levels of sphingoid base 1-phosphates in blood and tissues. The increased level of sphingoid base 1-phosphates in blood is a putative biomarker for FB ₁ inhibition of ceramide synthase in humans. Collection of blood spots on paper from finger sticks is a relatively non-invasive way to obtain blood for biomarker analysis. The objective of this study was to develop and validate in an animal model, and ultimately in humans, a method to estimate the volume of blood collected as blood spots on absorbent paper so as to allow quantification of the molar concentration of sphingoid base 1-phosphates in blood. To accomplish this objective, blood was collected from unexposed male LM/Bc and FB ₁-exposed pregnant LM/Bc mice and humans and applied to two types of absorbent paper. The sphingoid base 1-phosphates, absorbance at 270 nm (A ₂₇₀), and total protein content (Bradford) were determined in the acetonitrile:water 5% formic acid extracts from the dried blood spots. The results show that in both mouse and human the A ₂₇₀, total protein, and blood volume were closely correlated and the volume of blood spotted was accurately estimated using only the A ₂₇₀ of the extracts. In mouse blood spots, as in tissues and embryos, the FB ₁-induced changes in sphingolipids were correlated with urinary FB ₁. The half-life of FB ₁ in the urine was short (<24 h) and the elevation in sphingoid base 1-phosphates in blood was also short, although more persistent than the urinary FB ₁.