Regulation of LPS-induced tissue factor expression in human monocytic THP-1 cells by curcumin

Authors: GUO, WEIMIN - JM USDA HNRCA @ TUFTS; RATNASARI, ANITA - JM USDA HNRCA @ TUFTS; LI, JING - JM USDA HNRCA @ TUFTS; Meydani, Mohsen

Submitted to: Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/29/2008
Publication Date: 4/22/2009
Citation: Guo, W., Ratnasari, A., Li, J., Meydani, M. 2009. Regulation of LPS-induced tissue factor expression in human monocytic THP-1 cells by curcumin. Experimental Biology. 23: 717.2.

Interpretive Summary:

Technical Abstract: Tissue factor (TF) is a transmembrane receptor, which initiates thrombotic episodes associated with various diseases. In addition to membrane-bound TF, we have discovered an alternatively spliced form of human TF mRNA. It was later confirmed that this form of TF mRNA expresses a soluble protein circulating in blood. Curcumin, a natural polyphenol, has been shown to inhibit the induction of TF activity in cultured endothelial cells. Since monocytes are the only circulating blood cells that can be induced to express TF, we tested the effect of curcumin on TF expression in human monocytic THP-1 cell. We found that curcumin dose-dependently reduced LPS-induced procoagulant activity in intact THP-1 cells, which indicates decreased membrane-bound TF. However, curcumin at low concentration (10 microM) enhanced LPS-induced TF protein in the whole cell lysate, and the majority of the increased TF protein is a soluble form as indicated in Western blotting. TF mRNA level was also increased at 10 microM curcumin treatment; whereas high concentration of curcumin (40 microM) completely inhibited LPS-induced TF mRNA and protein expression. Overall, our data show that curcumin could suppress the LPS-induced procoagulant activity in THP-1 monocytic cells, but it requires further investigation to understand how the two forms of TF are regulated by curcumin. (Supported by USDA agreement #58-1950-7-707)