Aim: To study the effect of 17beta-estradiol on expression of chemokine receptor CXCR2 in monocytes in vivo.
Methods: Expressions of chemokine receptor CXCR2 mRNA and protein were measured by RT-PCR and flow cytometry, respectively.
Results: In both ovary-intact and ovariectomized (OVX) rats, CXCR2 protein and mRNA expression were significantly increased in rats fed with a high-cholesterol diet for 6 weeks. The cholesterol-induced increases in CXCR2 protein and mRNA expression were significantly attenuated in OVX rats injected with estradiol-17beta (17beta-E2) (5 and 20 microg x kg(-1) x d(-1)). In normal diet rats, CXCR2 protein and mRNA expression were increased in OVX rats compared with ovary-intact rats, and this increase was prevented by 17beta-E2.
Conclusion: Both basal and hypercholesterolemia-induced increases in chemokine receptor CXCR2 are modulated by physiological concentrations of estradiol.