Role of NO Pathway in Membrane Estrogen Receptor Mediated Proliferation and Apoptosis of Endothelial Progenitor Cells / 中山大学学报(医学科学版)

[Objective] The aim of the present study was to investigate the role of membrane estrogen receptor (mER) mediated pathway in the proliferation and apoptosis of endothelial progenitor cells (EPCs). [Methods] Bone marrow (BM)-derived EPCs were cultured. The cells were divided into different groups, plus or not plus estrogen receptor blocker (ICI 182,780), PI3K inhibitors (LY294002), and NOS inhibitor (L-NAME) to show the effect of E_2-BSA on EPCs. The proliferation of EPCs was determined by MTT and nitric oxide (NO) release was measured by chromatometry. Apoptotic cell death was determined using the Hochest 33258 staining. The expression of phosphorylated eNOS (p-eNOS) were detected by Western blot. [Results] E_2-BSA could increase EPCs proliferation, and this effect was inhibited by estrogen receptor blocker ICI 182,780, thus indicated that mER-initiated membrane signaling pathways were involved in the action of estrogen on EPCs. E_2-BSA increased nitric oxide production and inhibited apoptosis induced by serum withdrawal, and this effect also inhibited by PI3K inhibitor (LY294002), NOS inhibitor (L-NAME)and estrogen receptor blocker(ICI 182,780), thus indicated that PI3K/Akt/NO pathway was involved the effect of estrogen on EPCs apoptosis. Moreover, E_2-BSA treatment increased phosphorylation of eNOS (p-eNOS). PI3K inhibitors (LY294002) also blocked these effects. [Conclusions] The results of present study suggested that mER mediated EPCs proliferation and apoptosis were related to the PI3K/Akt/eNOS pathway.

Identification and analysis of membrane estrogen receptor in inters titial cells of Cajal / 重庆医科大学学报

Objective:To detect and analyze the membrane estrogen receptor(mER)in primary cultured interstitial cells of Cajal(ICC).Methods:Interstitial Cells of Cajal(ICC)'s surface binding sites for 17-?estradiol(E2)were detected by cell-impermeant ligand using confocal microscopy.Radioligand binding assay and Scatchard software were used to analyzed the characteristics of mER.Results:Immunofluorescence shows the staining pattern of nonfixed,nonpermeabilized ICC incubated with E2BSAFITC.The radioligand binding assay were analyzed by Scatchard software,The Bmax of mER was 45.75 fmol/mg protein and the kD was 0.717 3 nmol/L.Conclusion:A form of the estrogen receptor is present within the cell membrane of ICC and maybe capable of mediating rapid effect of estrogen.