Strong Alterations in the Sphingolipid Profile of Chickens Fed a Dose of Fumonisins Considered Safe

Abstract

Fumonisins (FB) are mycotoxins known to exert most of their toxicity by blocking ceramide synthase, resulting in disruption of sphingolipid metabolism. Although the effects of FB on sphinganine (Sa) and sphingosine (So) are well documented in poultry, little information is available on their other effects on sphingolipids. The objective of this study was to analyze the effects of FB on the hepatic and plasma sphingolipidome in chickens. The first concern of this analysis was to clarify the effects of FB on hepatic sphingolipid levels, whose variations can lead to numerous toxic manifestations. The second was to specify the possible use of an alteration of the sphingolipidome as a biomarker of exposure to FB, in addition to the measurement of the Sa:So ratio already widely used. For this purpose, we developed an UHPLC MS/MS method that enabled the determination of 82 SL, including 10 internal standards, in chicken liver and plasma. The validated method was used to measure the effects of FB administered to chickens at a dose close to 20 mg FB1 + FB2/kg feed for 9 days. Significant alterations of sphingoid bases, ceramides, dihydroceramides, glycosylceramides, sphingomyelins and dihydrosphingomyelins were observed in the liver. In addition, significant increases in plasma sphinganine 1-phosphate, sphingosine 1-phosphate and sphingomyelins were observed in plasma. Interestingly, partial least-squares discriminant analysis of 11 SL in plasma made it possible to discriminate exposed chickens from control chickens, whereas analysis of Sa and So alone revealed no difference. In conclusion, our results show that the effects of FB in chickens are complex, and that SL profiling enables the detection of exposure to FB when Sa and So fail.

Targeted Analysis of Sphingolipids in Turkeys Fed Fusariotoxins: First Evidence of Key Changes That Could Help Explain Their Relative Resistance to Fumonisin Toxicity

“…The marked increase in the Sa:So ratio in the liver of turkeys fed 20.2 mg of FB1 + FB2/kg fumonisins in the absence of toxicity agrees with previous results obtained in this animal species [23][24][25][26][27][47][48][49]. Deoxysphinganine was not affected by fumonisins in the present study, in agreement with results obtained in chickens fed a 20.8 mg of FB1 + FB2/kg diet for 9 days [35]. Deoxysphinganine has been found to be increased by FB1 in mammals and is recognized as a key toxic metabolite of sphinganine that, along with deoxyceramides, could contribute to fumonisin toxicity [4,17,50].…”

“…Because very-long-chain sphingomyelins were the most abundant in the liver of turkeys, the total concentration of sphingomyelins was increased. These results are in agreement with those obtained in chickens fed 20.8 mg of FB1 + FB2/kg for nine days [35]. The lack of a decrease in sphingomyelins at a concentration of 0.06 µmol of FB1/kg in the liver in this study is consistent with the IC50 of 0.7 µmol of FB1/L measured in mouse cerebellar neurons in culture for the synthesis of sphingomyelins [67].…”

“…The concentrations of glucosylceramides, hexosylceramides, and lactosylceramides in this study generally paralleled the concentrations of the corresponding ceramides in agreement with results obtained in chickens [35]. This result is consistent with the synthesis pathways of glycosylsphingolipids (Figure 1).…”

“…The analytes were separated on the UHPLC-system with a gradient of elution composed of methanol/acetonitrile/ isopropanol (4/1/1, v/v/v) and pure water, each containing 10 mM ammonium acetate and 0.2% formic acid (v/v) delivered at a flow rate of 0.3 mL/min. MRM parameters and retention times are detailed in [35]. Briefly, the m/z of the product ions used for quantification were 1dSo 266.4; d17:1 268.…”

“…Moreover, recent studies have indicated that fumonisins persist for a long time in the liver of chickens and turkeys and that toxins cumulate in the body over time [ 32 , 33 ]. Increases in free sphinganine and its 1-phosphate derivate are similar in avian species and in mammals [ 34 , 35 ], and measuring sphingoid bases alone is not sufficient to explain the relative resistance of avian species to fumonisin toxicity. The development of quantitative LC-MS/MS analysis based on the high-efficiency chromatographic separation of analytes now enables the quantitation of low-abundance but biologically important sphingolipids [ 36 ].…”