ABSTRACT
Objective To study the effects of 17estradiol on chemokine receptor CXCR2 expression in monocytes incubated with oxidized low density lipoproteins (oxLDL). Methods Human monocytic U937 cells were used as a model of monocytes. Expressions of CXC chemokine receptor CXCR2 mRNA and protein were measured by RT-PCR and FACS, respectively. Results The oxLDL(50 ?g/ml) significantly upregulated CXCR2 expression in U937 cells. 17estradiol (50 nmol/L) reduced expressions of CXCR2 mRNA and protein in U937 cells incubated with oxLDL (50 ?g/ml) , and the decrease of the CXCR2 protein was dependent on the concentration of 17estradiol (5-500 nmol/L). Conclusions 17estradiol can obviously reverse oxLDL-induced CXC chemokine receptor CXCR2 expression in U937 cells.
ABSTRACT
To study the effect of chemokine growth-regulated oncogene ? (GRO?) in process of LDL-induced atherosclerosis, a monocytic cell line, U937 cells and human umbilical vein endothelial cells were used. GRO? mRNA levels were significantly elevated after exposure of endothelial cells to oxLDL. A significant upregulation of GRO? surface expression in endothelial cells was induced by oxLDL with concentration-dependent and time-dependent manners, but no significant change in GRO? was observed in the medium. Upregulation of GRO? expression in endothelial cells enhanced monocytic cells adhesion to endothelial cells, but antibodies to GRO? inhibited the adhesion process. oxLDL functionally upregulates GRO? expression in endothelial cells.
ABSTRACT
To investigate the effect of menopause on chemokine receptor CXCR2 expression on monocyte, 21 postmenopausal and 20 premenopausal women were enrolled in the present study. Fasting venous blood was collected, and plasma estrogen levels were determined with radio immunoassay. Monocytes were separated from peripheral blood with gelatin method. Protein expression of chemokine receptor was assayed with flow cytometry and mRNA concentration was measured with RT PCR. The results showed that the levels of plasma estrogen decreased, whereas protein and mRNA expression of chemokine receptor CXCR2 increased after menopause. The plasma estrogen levels were negatively correlated with chemokine receptor CXCR2 expression in monocytes. These data suggested that the changes in CXCR2 on monocytes might contribute to,at least partially,the increased risk of developing coronary heart disease associated with estrogen secretory changes.
ABSTRACT
Objective: To study the change of chemokine receptor CXCR2 in monocytes in postmenopausal women with coronary artery disease (CAD) after estrogen replacement therapy. Methods: Randomized placebo controlled trial was conducted in 22 post menopausal women with CAD and 20 normal menopausal women by giving 0.625 mg premarin daily or vitamin C treatment for 3 months. Serum estradiol (E 2) and chemokine receptor CXCR2 in peripheral blood monocytes were measured at 0 and 3 months of treatment. Results:(1) E 2 and CXCR2 levels in the CAD group was lower than that in the normal group ( P