Abstract
Vascular smooth muscle cells (VSMCs) transdifferentiate into osteoblast-like cells during vascular calcification, inducing active remodeling and calcification of the extracellular matrix (ECM). Intracellular and extracellular enzymes, such as lysyl hydroxylase 1 (PLOD1) and lysyl oxidase (LOX), contribute to ECM maturation and stabilization. We assessed the contribution of these enzymes to hyperphosphatemia-induced calcification. Human and murine VSMCs were differentiated into functional osteoblast-like cells by high-phosphate medium (HPM) conditioning. HPM promoted ECM calcification and up-regulated osteoblast markers associated with induction of LOX and PLOD1 expression and with an increase in ECM-insoluble collagen deposition. Murine VSMCs from transgenic mice overexpressing LOX (TgLOX) exhibited an increase in HPM-dependent calcification and osteoblast commitment compared with wild-type cells. Similarly, enhanced HPM-induced calcification was detected in aorta from TgLOX. Conversely, b-aminopropionitrile (a LOX inhibitor) and LOX knockdown abrogated VSMC calcification and transdifferentiation. We found a significant positive association between LOX expression and vascular calcification in human atherosclerotic lesions. Likewise, 2,29-dipyridil (a PLOD inhibitor) and PLOD1 knockdown impaired HPM-induced ECM mineralization and osteoblast commitment. Our findings identify LOX and PLOD as critical players in vascular calcification and highlight the importance of ECM remodeling in this process.
Original language | English |
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Pages (from-to) | 4459-4469 |
Number of pages | 11 |
Journal | FASEB Journal |
Volume | 32 |
Issue number | 8 |
Early online date | 30 Jul 2018 |
DOIs | |
Publication status | Published - 1 Aug 2018 |
Keywords
- BAPN
- Dipyridyl
- Extracellular matrix
- LOX
- PLOD1