title: Zebrafish vitamin K epoxide reductases: expression in vivo, along extracellular matrix mineralization and under phylloquinone and warfarin in vitro exposure.
abstract: Vitamin K (VK) acts as a cofactor driving the biological activation of VK-dependent proteins and conferring calcium-binding properties to them. As a result, VK is converted into VK epoxide, which must be recycled by VK epoxide reductases (Vkors) before it can be reused. Although VK has been shown to play a central role in fish development, particularly during skeletogenesis, pathways underlying VK actions are poorly understood, while good and reliable molecular markers for VK cycle/homeostasis are still lacking in fish. In the present work, expression of 2 zebrafish vkor genes was characterized along larval development and in adult tissues through qPCR analysis. Zebrafish cell line ZFB1 was used to evaluate in vitro regulation of vkors and other VK cycle-related genes during mineralization and upon 24 h exposure to 0.16 and 0.8 µM phylloquinone (VK1), 0.032 µM warfarin, or a combination of both molecules. Results showed that zebrafish vkors are differentially expressed during larval development, in adult tissues, and during cell differentiation/mineralization processes. Further, several VK cycle intermediates were differentially expressed in ZFB1 cells exposed to VK1 and/or warfarin. Present work provides data identifying different developmental stages and adult tissues where VK recycling is probably highly required, and shows how genes involved in VK cycle respond to VK nutritional status in skeletal cells. Expression of vkor genes can represent a reliable indicator to infer VK nutritional status in fish, while ZFB1 cells could represent a suitable in vitro tool to get insights into the mechanisms underlying VK action on fish bone.
authors: Centre of Marine Sciences (CCMAR), University of Algarve, Campus of Gambelas, 8005-139, Faro, Portugal, nacfm@hotmail.com.
authors: Ignacio
authors: I
authors: Fernández
authors: Parameswaran
authors: P
authors: Vijayakumar
authors: Carlos
authors: C
authors: Marques
authors: M Leonor
authors: ML
authors: Cancela
authors: Paulo J
authors: PJ
authors: Gavaia
authors: Vincent
authors: V
authors: Laizé
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D002113:Calcification, Physiologic / Q000187:drug effects; D002460:Cell Line; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D010837:Vitamin K 1 / Q000494:pharmacology; D064417:Vitamin K Epoxide Reductases / Q000235:genetics* / Q000378:metabolism*; D014859:Warfarin / Q000494:pharmacology; D015027:Zebrafish / Q000235:genetics* / Q000254:growth & development*
chemical_list: D017931:DNA Primers; D014859:Warfarin; D010837:Vitamin K 1; D064417:Vitamin K Epoxide Reductases