New Insights on Vitamin K Metabolism in Senegalese sole (<i>Solea senegalensis</i>) Based on Ontogenetic and Tissue-Specific Vitamin K Epoxide Reductase Molecular Data

• Main Authors: Silvia Beato, Carlos Marques, Vincent Laizé, Paulo J. Gavaia, Ignacio Fernández
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: International Journal of Molecular Sciences
• Subjects: Vitamin K; gene expression; evolution; flatfish; nutrition; pollution
• Online Access: https://www.mdpi.com/1422-0067/21/10/3489
• ISSN: 1661-6596; 1422-0067

Vitamin K (VK) is a key nutrient for several biological processes (e.g., blood clotting and bone metabolism). To fulfill VK nutritional requirements, VK action as an activator of pregnane X receptor (Pxr) signaling pathway, and as a co-factor of γ-glutamyl carboxylase enzyme, should be considered. In this regard, VK recycling through vitamin K epoxide reductases (Vkors) is essential and should be better understood. Here, the expression patterns of <i>vitamin K epoxide reductase complex subunit 1</i> (<i>vkorc1</i>) and <i>vkorc1 like 1</i> (<i>vkorc1l1</i>) were determined during the larval ontogeny of Senegalese sole (<i>Solea senegalensis</i>), and in early juveniles cultured under different physiological conditions. Full-length transcripts for <i>ssvkorc1</i> and <i>ssvkorc1l1</i> were determined and peptide sequences were found to be evolutionarily conserved. During larval development, expression of <i>ssvkorc1</i> showed a slight increase during absence or low feed intake. Expression of <i>ssvkorc1l1</i> continuously decreased until 24 h post-fertilization, and remained constant afterwards. Both <i>ssvkors</i> were ubiquitously expressed in adult tissues, and highest expression was found in liver for <i>ssvkorc1</i>, and ovary and brain for <i>ssvkorc1l1</i>. Expression of <i>ssvkorc1</i> and <i>ssvkorc1l1</i> was differentially regulated under physiological conditions related to fasting and re-feeding, but also under VK dietary supplementation and induced deficiency. The present work provides new and basic molecular clues evidencing how VK metabolism in marine fish is sensitive to nutritional and environmental conditions.