Estrogen Regulation of Cell Adhesion Molecules, Affecting Monocyte and Endothelial Cell Interactions

Date of Award


Degree Type


Degree Name

Master of Science (MS)

First Advisor

Michael P McGuinness, PhD

Second Advisor

Brian Balin, PhD

Third Advisor

Marina D’Angelo, PhD


Estrogens have pro- and anti-inflammatory mechanisms of action. Specifically estrogens may regulate cell adhesion molecules and alter monocyte binding to endothelial cells. Estrogens bind to receptors present in the nucleus or on the plasma membrane. To determine if estrogen receptors are expressed on the plasma membrane of THP-1 cells, cells were incubated in primary antibody to either ERα, ERβ, actin, or no primary antibody. A secondary antibody conjugated to metallic beads was used to isolate cells. A significantly greater number of cells were isolated with antibodies to ERα or ERβ then cells with no primary antibody or primary antibody to actin. Western Blots were performed to measure the levels of ICAM-1 and VE-Cad in HUVECs and N-Cad and Alpha-L integrin in THP-1 cells. HUVEC cells and THP-1 cells were treated with 17 β estradiol (0-600nM) for 6, 12 and 24 hours. No significant differences were measured in the levels of these cell adhesion molecules. To measure the effect of estradiol on adherence of THP-1 cells to HUVEC cells, one or both cell lines were treated with 200nM estradiol for 24 hours prior to co-culture. The number of THP-1 cells adhering to HUVECs was determined after 15 minutes of co-culture. When HUVEC or THP-1 were treated with 17β estradiol there was a 2 fold decrease in the number of THP-1 cells adhering compared to untreated co-culture. When both HUVEC and THP-1 cells were treated there was a 5 fold decrease in adhering THP-1 cells compared to untreated co-culture. Without affecting the levels of cell adhesion molecules, we have demonstrated that estrogen is able to down-regulate adhesion between monocytes and endothelial cells. Signal transduction from estrogen receptors on the plasma membrane may result in sequestration of cell adhesion molecules in the cytoplasm, which decreases the ability of monocytes to bind to the endothelium.

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