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Induction of fecal cholesterol excretion is not effective for the treatment of hyperbilirubinemia in Gunn rats



Unconjugated hyperbilirubinemia, a feature of neonatal jaundice or Crigler–Najjar syndrome, can lead to neurotoxicity and even death. We previously demonstrated that unconjugated bilirubin (UCB) can be eliminated via transintestinal excretion in Gunn rats, a model of unconjugated hyperbilirubinemia, and that this is stimulated by enhancing fecal fatty acid excretion. Since transintestinal excretion also occurs for cholesterol (TICE), we hypothesized that increasing fecal cholesterol excretion and/or TICE could also enhance fecal UCB disposal and subsequently lower plasma UCB concentrations.


To determine whether increasing fecal cholesterol excretion could ameliorate unconjugated hyperbilirubinemia, we treated hyperbilirubinemic Gunn rats with ezetimibe (EZE), an intestinal cholesterol absorption inhibitor, and/or a liver X receptor (LXR) and farnesoid X receptor (FXR) agonist (T0901317 (T09) and obeticholic acid (OCA), respectively), known to stimulate TICE.


We found that EZE treatment alone or in combination with T09 or OCA increased fecal cholesterol disposal but did not lower plasma UCB levels.


These findings do not support a link between the regulation of transintestinal excretion of cholesterol and bilirubin. Furthermore, induction of fecal cholesterol excretion is not a potential therapy for unconjugated hyperbilirubinemia.


  • Increasing fecal cholesterol excretion is not effective to treat unconjugated hyperbilirubinemia.

  • This is the first time a potential relation between transintestinal excretion of cholesterol and unconjugated bilirubin is investigated.

  • Transintestinal excretion of cholesterol and unconjugated bilirubin do not seem to be quantitatively linked.

  • Unlike intestinal fatty acids, cholesterol cannot “capture” unconjugated bilirubin to increase its excretion.

  • These results add to our understanding of ways to improve and factors regulating unconjugated bilirubin disposal in hyperbilirubinemic conditions.

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Fig. 1: The effect of stimulation of FNS on plasma levels of bilirubin in hyperbilirubinemic rats.
Fig. 2: Schematic representation of the calculated cholesterol fluxes.
Fig. 3: The effect of T09 and EZE on UCB in bile and feces in Gunn rats.
Fig. 4: The effect of T09 and EZE treatment on LXR target gene expression and triglyceride levels.
Fig. 5: The effect of OCA and EZE treatment on FXR target genes and bile acids in Gunn rats.


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The authors gratefully acknowledge the excellent technical contributions to this study by Rick Havinga, Renze Boverhof, Martijn Koehorst, and Anouk Bos. We thank Folkert Kuipers for helpful discussions and advice. This study was funded by a grant from De Cock Hadders stichting. L.V. received a grant from the Czech Ministry of Health (RVO-VFN64165).

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M.B. designed and performed the experiments, analyzed and interpreted data, and wrote the manuscript. I.P.v.d.P. interpreted data and wrote the manuscript. A.D. and N.C. analyzed data and reviewed the manuscript. L.V. interpreted data and reviewed the manuscript. J.W.J. and H.J.V. designed the experiments, interpreted data, and wrote the manuscript.

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Correspondence to Henkjan J. Verkade.

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Blankestijn, M., van de Peppel, I.P., Dvorak, A. et al. Induction of fecal cholesterol excretion is not effective for the treatment of hyperbilirubinemia in Gunn rats. Pediatr Res (2020).

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