Vascular endothelial cells (EC)are an important target of estrogen action through both the classical genomic (i.e. nuclear-initiated) activities of estrogen receptors ␣ and ␤ (ER␣ and ER␤) and the rapid "nongenomic" (i.e. membrane-initiated) activation of ER that stimulates intracellular phosphorylation pathways. We tested the hypothesis that the red wine polyphenol trans-resveratrol activates MAPK signaling via rapid ER activation in bovine aortic EC, human umbilical vein EC, and human microvascular EC. We report that bovine aortic EC, human umbilical vein EC, and human microvascular EC express ER␣ and ER␤. We demonstrate that resveratrol and estradiol (E 2 ) rapidly activated MAPK in a MEK-1, Src, matrix metalloproteinase, and epidermal growth factor receptor-dependent manner. Importantly, resveratrol activated MAPK and endothelial nitric-oxide synthase (eNOS) at nM concentrations (i.e. an order of magnitude less than that required for ER genomic activity) and concentrations possibly achieved transiently in serum following oral red wine consumption. Co-treatment with ER antagonists ICI 182,780 or 4-hydroxytamoxifen blocked resveratrol-or E 2 -induced MAPK and eNOS activation, indicating ER dependence. We demonstrate for the first time that ER␣-and ER␤-selective agonists propylpyrazole triol and diarylpropionitrile, respectively, stimulate MAPK and eNOS activity. A red but not a white wine extract also activated MAPK, and activity was directly correlated with the resveratrol concentration. These data suggest that ER may play a role in the rapid effects of resveratrol in EC and that some of the atheroprotective effects of resveratrol may be mediated through rapid activation of ER signaling in EC.Epidemiological studies have indicated that the consumption of red wine reduces the incidence of mortality from coronary heart disease (CHD) 1 (1, 2). The cardioprotective effect has been attributed to the polyphenol fraction of red wine (1). A key polyphenol in red wine is resveratrol, trans-3,5,4Ј-trihydroxystilbene, from grape skin. Red wine contains 1-75 mg of transresveratrol/liter (3). Studies in male rats demonstrated that an alcohol-free red wine extract and resveratrol protect the heart from ischemia reperfusion injury (4). Rodent studies showed that orally administered resveratrol is absorbed in the gut, has high affinity for heart and liver (5, 6), and is metabolized to glucuronides that have a t1 ⁄2 of ϳ1.5 h (7). A recurrent question is whether resveratrol, at concentrations present in red wine, is effective in vivo. The oral absorption of 25 mg of trans-

The higher frequency of lung adenocarcinoma in women smokers than in men smokers suggests a role for gender-dependent factors in the etiology of lung cancer. We evaluated estrogen receptor (ER) a and b expression and activity in human lung adenocarcinoma cell lines and normal lung fibroblasts. Full-length ERa and ERb proteins were expressed in all cell lines with higher ERb than ERa. Although estradiol (E 2 ) binding was similar, E 2 stimulated proliferation only in cells from females, and this response was inhibited by anti-estrogens 4-hydroxytamoxifen (4-OHT) and ICI 182,780. In contrast, E 2 did not stimulate replication of lung adenocarcinoma cells from males and 4-OHT or ICI did not block cell proliferation. Similarly, transcription of an estrogen response element-driven reporter gene was stimulated by E 2 in lung adenocarcinoma cells from females, but not males. Progesterone receptor (PR) expression was increased by E 2 in two out of five adenocarcinoma cell lines from females, but none from males. E 2 decreased E-cadherin protein expression in some of the cell lines from females, as it did in MCF-7 breast cancer cells, but not in the cell lines from males. Thus, ERa and ERb expression does not correlate with the effect of ER ligands on cellular activities in lung adenocarcinoma cells. On the other hand, coactivator DRIP205 expression was higher in lung adenocarcinoma cells from females versus males and higher in adenocarcinoma cells than in normal human bronchial epithelial cells. DRIP205 and other ER coregulators may contribute to differences in estrogen responsiveness between lung adenocarcinoma cells in females and males.

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Calcium transport across a monolayer of Madin-Darby canine kidney (MDCK) cells was measured in response to stimulation of the basal surface with calcium-sensing receptor (CaR) agonists. Stimulation of the CaR resulted in a time- and concentration-dependent inhibition of calcium transport but did not change transepithelial voltage or resistance. Inhibition of transport was not altered by pretreatment of cells with pertussis toxin but was blocked by the phospholipase C (PLC) inhibitor U-73122. To determine a potential mechanism by which the CaR could inhibit calcium transport, we measured activity of the plasma membrane calcium ATPase (PMCA). Stimulation of the CaR on the basal surface resulted in an inhibition of the PMCA in a concentration- and PLC-dependent manner. Thus stimulation of the CaR inhibits both calcium transport and PMCA activity through a PLC-dependent pathway. These studies provide the first direct evidence that calcium can inhibit its own transcellular absorption in a model of the distal tubule. In addition, they provide a potential mechanism for the CaR to inhibit calcium transport, inhibition of PMCA.

Abstract-IntracellularCa 2ϩ is increased in the platelets of hypertensive individuals. Previously, we demonstrated that platelet plasma membrane Ca 2ϩ -ATPase (PMCA) activity inversely correlates with diastolic blood pressure and that inhibition of this Ca 2ϩ pump could explain the elevation of cytosolic Ca 2ϩ in hypertension. More recently, we discovered that PMCA is phosphorylated on tyrosine residues during thrombin-stimulated platelet aggregation and that this phosphorylation causes inhibition of PMCA activity. In the present work, we tested the hypothesis that tyrosine phosphorylation of PMCA in hypertensive patients could account for the observed inhibition of the Ca 2ϩ pump. Platelets were obtained from untreated hypertensive and normotensive volunteers. PMCA was immunoprecipitated from solubilized platelets, and tyrosine phosphorylation was quantified by chemiluminescence of immunoblots treated with anti-phosphotyrosine. PMCA content was measured on the same immunoblots by stripping and reprobing with anti-PMCA. Phosphorylation was reported as normalized phosphotyrosine chemiluminescence per nanogram PMCA (meanϮSE). The average PMCA tyrosine phosphorylation for 15 normotensive subjects was 0.53Ϯ0.09, whereas the average for 8 hypertensive individuals was 1.82Ϯ0.25 (PϽ0.0005, Mann-Whitney U test). Age, gender, and systolic blood pressure did not correlate with PMCA phosphorylation. These results suggest that PMCA in platelets of hypertensive individuals is inhibited because of tyrosine phosphorylation, resulting in increased platelet intracellular Ca 2ϩ , hyperactive platelets, and increased risk of heart attack and stroke.