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Jian-Su Shao, Su-Li Cheng, Joyce M. Pingsterhaus, Nichole Charlton-Kachigian, Arleen P. Loewy, Dwight A. Towler
Published in Volume 115, Issue 5
J Clin Invest. 2005; 115(5):1210–1220 doi:10.1172/JCI24140
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Figure 11

Working model of Msx2 actions during vascular calcification. High-fat diets upregulate aortic BMP2 expression (10). In addition to providing progenitors for medial disease processes (40, 41, 43), Msx2-expressing adventitial myofibroblasts produce an osteogenic milieu via induction of Wnt agonists and inhibition of the LRP5/6 antagonist, Dkk1. This causes nuclear localization and activation of β-catenin — an indispensable coregulator of osteoblast differentiation and mineralization (24); as reflected by TCF/LEF-dependent transcription, activation occurs in a subset of medial CVCs. CVCs of Demer (50), perhaps derived from migratory adventitial progenitors (10, 40, 41, 43), respond by upregulating ALP expression via key osteogenic transcription factors (11). Vascular PTH1R signaling dampens Msx2-Wnt signaling. In ESRD, PTH1R downregulation (desensitization) arising from hyperparathyroidism may accelerate vascular disease. Although Osx is upregulated by Msx2 (10), the relationship between β-catenin:TCF/LEF signaling (24) and Osx (60) in mineralization has yet to be clarified. The pyrophosphate-generating (PPi-generating) enzyme ENPP1 inhibits arterial calcification, stabilizing the VSMC phenotype (55).