Vitamin K preserves gamma-glutamyl carboxylase activity against carbamylations in uremia: Implications for vascular calcification and adjunct therapies

Kaesler, Nadine, Kaushik, Suresh, Frisch, Janina, Ziegler, Susanne, Grommes, Jochen, Gombert, Alexander, Roma, Leticia Prates, Kuppe, Christoph, Jankowski, Joachim, Floege, Jürgen, de la Puente-Secades, Sofia, Kramann, Rafael and Jankowski, Vera 2025. Vitamin K preserves gamma-glutamyl carboxylase activity against carbamylations in uremia: Implications for vascular calcification and adjunct therapies. Acta Physiologica 241 (5) , e70040. 10.1111/apha.70040

PDF - Published Version Available under License Creative Commons Attribution. Download (2MB)

Abstract

Aim: Vascular calcification contributes to morbidity and mortality in aging and is accelerated in diabetes and in chronic kidney disease. Matrix Gla Protein is a potent inhibitor of vascular calcification, which is activated by the vitamin K-dependent gamma-glutamyl carboxylase (GGCX). However, through a currently unidentified mechanism, the activity of GGCX is reduced in experimental uremia, thereby contributing to the promotion of vascular calcifications. In this study, we aim to identify the cause of these functional alterations and to stimulate the enzyme activity by potential GGCX binding compounds as a new avenue of therapy. Methods: Two rodent models of experimental uremia and human carotid plaques were assessed for GGCX activity and modifications, as well as calcification. In silico compound screening via BindScope identified potential binding partners of GGCX which were further validated in functional assays for enzymatic activity changes and for in vitro calcification. Mass spectrometry was applied to monitor molecular mass changes of the GGCX. Results: Mass spectrometry analysis revealed post-translational modifications of the GGCX in uremic rats and mice, as well as in calcified human carotid plaques. Functional assays showed that the post-translational carbamylation of GGCX reduced the enzyme activity, which was prevented by vitamin K2. Chrysin, identified by compound screening, stimulated GGCX activity, reduced calcium deposition in VSMCs, and oxidized GGCX at lysine 517. Conclusion: In conclusion, this study clearly demonstrates that the vitamin K-dependent enzyme GGCX plays a significant role in uremic calcification and may be modulated to help prevent pathological changes.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Schools > Biosciences
Additional Information:	License information from Publisher: LICENSE 1: Title: cc by, Type: cc by
Publisher:	Wiley
ISSN:	1748-1716
Date of First Compliant Deposit:	22 April 2025
Date of Acceptance:	20 March 2025
Last Modified:	22 Apr 2025 11:00
URI:	https://orca.cardiff.ac.uk/id/eprint/177815

Actions (repository staff only)

Edit Item