1α,25-Dihydroxyvitamin D ₃ and Its Potent Synthetic Analogs Downregulate Tissue Factor and Upregulate Thrombomodulin Expression in Monocytic Cells, Counteracting the Effects of Tumor Necrosis Factor and Oxidized LDL

Abstract

Because KY3 has the highest affinity for vitamin D receptor, our findings suggest that TF and TM regulation by 1, 25(OH)(2)D(3) analogs is also mediated by vitamin D receptor. The 1, 25(OH)(2)D(3) analogs KY3 and 22-oxacalcitriol may have the potential to serve as an agent for preventing and treating atherosclerotic and other cytokine-mediated thrombotic diseases and as a tool for studying the molecular mechanisms of TF and TM regulation.

1,25(OH)2D3 blocks TNF-induced monocytic tissue factor expression by inhibition of transcription factors AP-1 and NF-κB

“…Further studies are necessary to elucidate the intricate pathways that NF-kB and AP-1 play in TF gene expression. 14 We used 0.1 mM of 1,25(OH) 2 D 3 in this study to reveal the effect on TF expression. The more potent 1,25(OH) 2 D 3 analogs, which have far stronger binding affinity to VDR and which lack an adverse effect of hypercalcemia, have been synthesized.…”

“…As the anticoagulant effects of 1,25(OH) 2 D 3 have been detected in monocytic leukemia cell line U937 as well as in human peripheral monocytes, 14 we primarily used monoblastic leukemia cell line THP-1 cells and partly U937 cells in this study, both of which were provided by Health Science Research Bank. Cells were cultured in RPMI-1640 medium supplemented with 10% fetal calf serum, 0.2% sodium carbonate, 2 mM glutamine, and 50 U/ml penicillin-streptomycin.…”

“…After incubation at 371C for 2 min, 0.1 ml of 25 mM calcium chloride was added and the plasma recalcification time was measured by a CA-100 semiautomatic coagulator (Sysmax, Kobe, Japan). The procoagulant activity associated with the surface of THP-1 cells was attributable to the occurrence of TF expression 13,14 and thus the prolongation of the recalcfication time is mainly due to downregulation of TF expression. TF cofactor activity was quantitatively measured by reference to a standard curve constructed with human placental TF, and the amount of TF activity that yielded a 50-s recalcification time was defined as 1 U/ml.…”

“…11,12 We have previously found that 1,25(OH) 2 D 3 and its synthetic analogs downregulate TF and upregulate thrombomodulin (TM) expression in monocytic cells, counteracting the effects of TNF and oxidized LDL. 13,14 Pathogenic expression of TF mRNA in monocytic cells was markedly downregulated by 1,25(OH) 2 D 3 and its synthetic analogs . Several subsequent studies have reported that the vitamin D/VDR system plays a physiological role in vivo in the maintenance of antithrombotic homeostasis.…”

Disruption of Nuclear Vitamin D Receptor Gene Causes Enhanced Thrombogenicity in Mice

“…Koyama and colleagues (10,12) have found that a hormonally active form of vitamin D, 1␣,25-dihydroxyvitamin D3, as well as retinoic acid, exert anticoagulant effects by up-regulating the expression of the anticoagulant glycoprotein, thrombomodulin (TM), and by down-regulating the expression of a critical coagulation factor, tissue factor (TF), in cultured monocytic cells and human peripheral monocytes. However, it remains unclear whether activation of nuclear VDR can elicit antithrombotic actions in vivo.…”