Chemical and metabolomic screens identify novel biomarkers and antidotes for cyanide exposure

Abstract

Exposure to cyanide causes a spectrum of cardiac, neurological, and metabolic dysfunctions that can be fatal. Improved cyanide antidotes are needed, but the ideal biological pathways to target are not known. To understand better the metabolic effects of cyanide and to discover novel cyanide antidotes, we developed a zebrafish model of cyanide exposure and scaled it for high-throughput chemical screening. In a screen of 3120 small molecules, we discovered 4 novel antidotes that block cyanide toxicity. The most potent antidote was riboflavin. Metabolomic profiling of cyanide-treated zebrafish revealed changes in bile acid and purine metabolism, most notably by an increase in inosine levels. Riboflavin normalizes many of the cyanide-induced neurological and metabolic perturbations in zebrafish. The metabolic effects of cyanide observed in zebrafish were conserved in a rabbit model of cyanide toxicity. Further, humans treated with nitroprusside, a drug that releases nitric oxide and cyanide ions, display increased circulating bile acids and inosine. In summary, riboflavin may be a novel treatment for cyanide toxicity and prophylactic measure during nitroprusside treatment, inosine may serve as a biomarker of cyanide exposure, and metabolites in the bile acid and purine metabolism pathways may shed light on the pathways critical to reversing cyanide toxicity.

15 years of zebrafish chemical screening

“…Chemically induced changes in metabolomic profiles, for example, could be used as phenotypic endpoints in zebrafish chemical screens [73, 74] in addition to epigenetic, gene expression or proteomic readouts.…”

Characterization of a Mouse Model of Oral Potassium Cyanide Intoxication

“…Potassium cyanide (CAS 151-50-8, purity of 99.8%), tetrabutylammonium sulfate, 2,3,4,5,6-pentafluorobenzyl bromide, tetraborate decahydrate, thiocyanate, and potassium 13 C 15 Ncyanide and potassium 13 …”

“…12 A number of compounds are being investigated for efficacy in treatment of CN intoxication. [13][14][15][16][17] However, little information is available on the effects of CN in young animals. Reports have indicated age differences in rhodanese activity, a key enzyme in degradation of CN.…”

In vivo cell biology in zebrafish – providing insights into vertebrate development and disease

“…By using transgenic zebrafish expressing a GFP-tagged secreted glycoprotein in hepatocytes Tsedensodnom et al, 2013;Xie et al, 2010), and zebrafish that express fluorescent protein markers of the hepatocyte secretory organelles and of other cells in the liver (Yin et al, 2012), the mechanisms by which alcohol and other drugs cause organ-specific and organelle-mediated toxicity can be uniquely addressed. Moreover, large-scale drug screens exploit the ease of treating zebrafish with drugs (Peterson and Macrae, 2012) and have identified compounds modulating processes ranging from metabolism (Nath et al, 2013) to sleep (Rihel and Schier, 2012). …”