Augmentation of thalidomide teratogenicity in human CYP3As expressing zebrafish

Abstract

It is well known that the active metabolites of compounds could be involved in the pharmacological and toxicological endpoints. On the other hand, it has been believed long time that thalidomide (TM) causes typical short limb syndrome restricted to primates including human and rabbits. Zebrafish attracted much attention since it was reported that they showed pectoral fin defects in response to TM twelve years ago. However, it was also reported recently that conventional aqueous exposure hardly affects normal development of zebrafish. TM was also reported to cause disorder in forelimb development in mice expressing human cytochrome P450 3As (hCYP3As). In the present study, we prepared zebrafish expressing some hCYPs and examined the effects of TM. F0 embryos that were injected with both transposon vector containing some human CYPs-2A peptide-enhanced green fluorescent protein (EGFP) and transposase capped RNA. Aqueous exposure to TM had no effect on wild-type embryos/larvae at all. By contrast, TM caused pectoral fin hypoplasia and other malformation in zebrafish embryos/larvae that were incorporated with hCYP3A4, 3A7 but not hCYP1A1 in their genome (F0). hCYP3A7-TG embryos/larvae expressing EGFP fluorescence throughout the body showed hypoplasia of pectoral fin and edema by exposure to TM. The results suggest the augmentation of thalidomide teratogenicity by hCYP3A4 and 3A7 but not 1A1.