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International journal of cardiology 11/2012; · 7.08 Impact Factor
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ABSTRACT: Estrogen exerts vascular protective effects, but the underlying mechanisms remain to be understood fully. In recent years, hydrogen sulfide (H(2)S) has increasingly been recognized as an important signaling molecule in the cardiovascular system. Vascular H(2)S is produced from L-cysteine, catalyzed by cystathionine γ-lyase (CSE). In our study, apolipoprotein E (ApoE)-deficient mice were ovariectomized and implanted with placebo (OVX mice) or 17β-estradiol (E(2)) pellets (OVX + E(2) mice). Compared with OVX mice, OVX + E(2) mice showed increased plasma H(2)S levels (P = 0.012) and decreased aortic lesion area (P = 0.028). These effects were largely reversed when supplementing with the irreversible CSE inhibitor DL-propargylglycine (PPG) in the OVX + E(2) + PPG mice. Meanwhile, the nitric oxide and prostacyclin-resistant responses to cumulative application of acetylcholine (ACh) were studied among all the three groups of femoral arteries. Compared with the arteries in the OVX group, the vasodilator sensitivity of arteries to ACh was increased in the OVX + E(2) group and attenuated in the OVX + E(2) + PPG group. E(2) and estrogen receptor (ER) α agonist 4',4″,4'″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol rapidly increased H(2)S release in human endothelial cells, but not partially selective ERβ agonist 2,3-bis-(4-hydroxyphenyl)-propionitrile. These effects were inhibited by ER antagonist ICI 182780 or by protein kinase G (PKG) inhibitor KT5823. Furthermore, endothelial PKG activity was increased by E(2) (P = 0.003) and E(2)-induced vasodilation was inhibited by KT5823 (P = 0.009). In conclusion, the endothelial CSE/H(2)S pathway is activated by E(2) through PKG, which leads to vasodilation. These actions may be relevant to estrogen's anti-atherogenic effect.
Molecular Human Reproduction 10/2012; · 3.85 Impact Factor
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ABSTRACT: Opioids have been widely used in clinical practice as potent pain relievers for centuries. However, opioids have many deleterious effects. It has been reported that opioid increases tau protein phosphorylation. Hyperphosphorylation of tau is also a pathological feature of Alzheimer's disease and other chronic neurodegenerative disorders. However, the underlying mechanism by which opioids enhance tau phosphorylation is not yet known. In this study, we treated rat embryo cortical neurons with morphine and observed its effect on tau phosphorylation. We found that morphine induced tau hyperphosphorylation and increased levels of phospho-JNK and phospho-p38; these effects were blocked by pretreatment with naloxone. Inhibition of JNK by SP600125 significantly reduced tau hyperphosphorylation in neurons treated with morphine. Similarly, SB203580, an antagonist of p38 MAPK, abolished tau hyperphosphorylation in neurons treated with morphine. Our data suggest that JNK/p38 MAPK, activated by morphine in an opioid receptor-dependent manner, may lead to tau hyperphosphorylation.
Behavioural brain research 09/2012; 237C:249-255. · 3.22 Impact Factor
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ABSTRACT: Metabolic syndrome (MBS), a cluster of metabolic abnormalities and visceral fat accumulation, increases cardiovascular risks in postmenopausal women. In addition to visceral fat, perivascular adipose tissue has been recently found to play an important role in vascular pathophysiology. Hence, the present study investigates the effects of estrogen on both intra-abdominal fat (visceral fat) and periaortic fat (perivascular fat) accumulation as well as hypoxia in ovariectomized female rats. Female rats were divided into sham operation, ovariectomy and ovariectomy with 17β-estradiol supplementation groups. Twelve weeks later, we found that estrogen improved MBS via reducing body weight gain, the weight of periaortic and intra-abdominal fat, hepatic triglyceride, and total serum cholesterol levels. Estrogen also increased insulin sensitivity through restoring glucose and serum leptin levels. For periaortic fat, western blot showed estrogen inhibited hypoxia by reducing the levels of VEGF and HIF-1α, which is consistent with the results from immunohistochemical staining. The correlation analysis indicated that perivascular fat had a positive correlation with body weight, intra-abdominal fat or serum total cholesterol, but a negative correlation with insulin sensitivity index. For intra-abdominal fat, real-time fluorescent RT-PCR showed estrogen improved fat dysfunction via reducing the levels of relative leptin, MCP-1 but increasing adiponectin mRNA. Estrogen reduced the levels of VEGF and HIF-1α to inhibit hypoxia but restored the levels of PPARγ and Srebp-1c, which are important for lipid capacity function of intra-abdominal fat. These results demonstrated estrogen improved MBS through down-regulating VEGF and HIF-1α to inhibit hypoxia of periaortic and intra-abdominal fat in ovariectomized female rats.
Molecular Biology Reports 05/2012; 39(8):8177-85. · 2.93 Impact Factor
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ABSTRACT: cAMP response element-binding protein(CREB) and the cAMP cascade play a pivotal role in the opiate-dependence. The blockade of this cascade is believed to attenuate signs of physical opiate withdrawal. A lentiviral vector (LV) expressing a small hairpin RNA (shRNA) to silence CREB in vitro and in vivo was used in this study. The effect of the shRNA on the regulation of the relevant protein expression and the signs of opiate withdrawal were subsequently evaluated in rats undergoing chronic morphine treatment. In cultured primary locus coeruleus (LC) neurons, the designed lentiviral vectors were successfully infected into the cells and led to 70% knockdown in CREB expression. In cells treated with chronic morphine, the expression of CREB, adenylyl cyclase (AC) and protein kinase A (PKA) were increased, while in cells infected with LV-CREB3, treated with chronic morphine treatment failed to increase the expressions of CREB and AC. Consistently, in the rat model for chronic morphine treatment, morphine increased the expression of CREB, AC and PKA in LC neurons. However, in rats received bilateral microinjections of LV-CREB3 into the LC, morphine did not alter the levels of these proteins. Moreover, microinjection of LV-CREB3 significantly attenuated the appearance of certain withdrawal behaviors. In conclusion, the lentiviral vectors expressing CREB shRNA inhibited the increase of CREB and AC expression induced by chronic morphine treatment both in vivo and in vitro. This inhibition was associated with the alleviation of some withdrawal behaviors. These findings suggested that lentivirus-mediated RNA interference could be useful for opiate-dependence therapy.
Behavioural brain research 05/2012; 233(1):217-23. · 3.22 Impact Factor
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ABSTRACT: Individuals with prehypertension are at risk of hypertension and cardiovascular diseases, and yet efficient interventions are lagging behind. Studies indicate that heart rate variability-biofeedback (HRV-BF) increases HRV and baroreflex sensitivity (BRS) as well as reduces related pathological symptoms, suggesting potentially beneficial effects of HRV-BF on prehypertension, but little is known about these effects. In this study, these effects were investigated and their mechanisms were explored.
The effect of HRV-BF on prehypertension in young adults and its potential mechanism were explored.
Forty-three (43) individuals with prehypertension were recruited and classified into three categories: HRV-BF group, slow abdominal breathing group, and control group. All groups were assessed with measurements of noninvasive blood pressure (BP), BRS, respiration, and galvanic skin response (GSR) at pre-intervention, in the entire process of each session, at postintervention, as well as at a 3-month follow-up. Interventions: Subjects participated in a 10-session HRV-BF protocol or simple slow abdominal breathing protocol conducted over 5 weeks. A 3-month follow-up was also performed on these individuals.
The incidence of prehypertension was as high as 14.5% in young college students. Individuals with prehypertension were lower in BRS (7.5±5.2 ms/mm Hg) and HRV (log10-transformed of the standard deviation of normal-to-normal beats [SDNN]=1.62±0.13 ms, lgTotal power of spectral density in the range of frequencies between 0 and 0.4Hz (TP)=8.02±0.55 ms2) than those with normal blood pressure (BRS=18.4±7.4 ms/mm Hg, lgSDNN=1.79±0.10 ms, lgTP=8.68±0.85 ms2). HRV-BF reduced blood pressure (from 131.7±8.7/79.3±4.7 mm Hg to 118.9±7.3 mm Hg/71.9±4.9 mm Hg, p<0.01), increased BRS (from 7.0±5.9 ms/mm Hg to 15.8±5.3 ms/mm Hg, p<0.01) and increased HRV (lgSDNN from 1.61±0.11 to 1.75±0.05 ms, and lgTP from 8.07±0.54 to 9.08±0.41 ms2, p<0.01). These effects were more obvious than those of the slow-breathing group, and remained for at least 3 months. HRV-BF also significantly increased vagus-associated HRV indices and decreased GSR (indices of sympathetic tone).
These effects suggest that HRV-BF, a novel behavioral neurocardiac intervention, could enhance BRS, improve the cardiac autonomic tone, and facilitate BP adjustment for individuals with prehypertension.
Journal of alternative and complementary medicine (New York, N.Y.) 02/2012; 18(2):143-52. · 1.69 Impact Factor
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ABSTRACT: The mechanisms of progesterone on endothelial cell motility are poorly investigated. Previously we showed that progesterone stimulated endothelial cell migration via the activation of actin-binding protein moesin, leading to actin cytoskeleton remodelling and the formation of cell membrane structures required for cell movement. In this study, we investigated the effects of progesterone on the formation of focal adhesion complexes, which provide anchoring sites for cell movement. In cultured human umbilical endothelial cells, progesterone enhanced focal adhesion kinase (FAK) phosphorylation at Tyr(397) in a dose- and time-dependent manner. Several signalling inhibitors interfered with progesterone-induced FAK activation, including progesterone receptor (PR) antagonist ORG 31710, specific c-Src kinase inhibitor PP2, phosphatidylinosital-3 kinase (PI3K) inhibitor wortmannin as well as ρ-associated kinase (ROCK-2) inhibitor Y27632. It suggested that PR, c-Src, PI3K and ROCK-2 are implicated in this action. In line with this, we found that progesterone rapidly promoted c-Src/PI3K/Akt activity, which activated the small GTPase RhoA/ρ-associated kinase (ROCK-2) complex, resulting in FAK phosphorylation. In the presence of progesterone, endothelial cells displayed enhanced horizontal migration, which was reversed by small interfering RNAs abrogating FAK expression. In conclusion, progesterone promotes endothelial cell movement via the rapid regulation of FAK. These findings provide new information on the biological actions of progesterone on human endothelial cells that are relevant for vascular function.
Journal of Cellular and Molecular Medicine 03/2011; 16(2):296-305. · 4.13 Impact Factor
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ABSTRACT: Estrogen promotes breast cancer metastasis. However, the detailed mechanism remains largely unknown. The actin binding protein ezrin is a key component in tumor metastasis and its over-expression is positively correlated to the poor outcome of breast cancer. In this study, we investigate the effects of 17β-estradiol (E2) on the activation of ezrin and its role in estrogen-dependent breast cancer cell movement. In T47-D breast cancer cells, E2 rapidly enhances ezrin phosphorylation at Thr(567) in a time- and concentration-dependent manner. The signalling cascade implicated in this action involves estrogen receptor (ER) interaction with the non-receptor tyrosine kinase c-Src, which activates the phosphatidylinositol-3 kinase/Akt pathway and the small GTPase RhoA/Rho-associated kinase (ROCK-2) complex. E2 enhances the horizontal cell migration and invasion of T47-D breast cancer cells in three-dimensional matrices, which is reversed by transfection of cells with specific ezrin siRNAs. In conclusion, E2 promotes breast cancer cell movement and invasion by the activation of ezrin. These results provide novel insights into the effects of estrogen on breast cancer progression and highlight potential targets to treat endocrine-sensitive breast cancers.
PLoS ONE 01/2011; 6(7):e22439. · 4.09 Impact Factor
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ABSTRACT: Genistein prevents atherosclerosis by exerting protective effects on blood vessels. The aim of this study is to investigate the role of caveolin1 and sprouty1 in the regulation of proliferation of vascular smooth muscle cell (VSMC) and endothelial cell by genistein. Using thiazolyl blue tetrazolium bromide(MTT) and [3H]-TdR assay, we found genistein inhibited angiotensin II-induced proliferation in primary cultured VSMC while it stimulated proliferation of quiescent endothelial cells. The effects were attenuated by caveolin1 or sprouty1 siRNA. Western blot analysis indicated that genistein attenuated the phosphorylation of extracellular regulated kinase1/2(ERK1/2) in angiotensin II-induced proliferated VSMC but stimulated the phosphorylation of ERK1/2 in quiescent endothelial cell. Double staining immunofluorescence identified caveolin1 and sprouty1 coexpressed in the cytoplasm of both VSMC and endothelial cell. Genistein increased the expression of caveolin1, p-caveolin1 and sprouty1 in VSMC, while it had opposite effects in quiescent endothelial cell. Co-immunoprecipitation suggested that genistein exerted its effects through interaction of caveolin1 and sprouty1. Our results demonstrate that the inhibition of angiotensin II-induced proliferation of VSMC and stimulation of quiescent endothelial cell by genistein are regulated by caveolin1 and sprouty1, which are implemented through Ras/MAPK pathway.
European journal of pharmacology 12/2010; 648(1-3):153-61. · 2.59 Impact Factor
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ABSTRACT: Atherosclerosis is an inflammatory disease where lipopolysaccharide (LPS) triggers the release of inflammatory cytokines that accelerate its initiation and progression. Estrogen has been proven to be vasoprotective against atherosclerosis; however, the anti-inflammatory function of estrogen in the vascular system remains obscure. In this study, we investigated the effect of estrogen on LPS-induced monocyte chemoattractant protein-1 (MCP-1; listed as CCL2 in the MGI database) production in vascular smooth muscle cells (VSMCs). LPS significantly enhances MCP-1 production and this is dependent on nuclear factor kappa B (NFkappaB) signaling, since the use of NFkappaB inhibitor pyrrolidine dithiocarbamate or the silencing of NFkappaB subunit p65 expression with specific siRNA largely impairs LPS-enhanced MCP-1 production. On the contrary, 17beta-estradiol (E(2)) inhibits LPS-induced MCP-1 production in a time- and dose-dependent manner, which is related to the suppression of p65 translocation to nucleus. Furthermore, p38 MAPK is rapidly activated in response to LPS, while E(2) markedly inhibits p38 MAPK activation. Transfection with p38 MAPK siRNA or the use of p38 MAPK inhibitor SB203580 markedly attenuates LPS-stimulated p65 translocation to nucleus and MCP-1 production, suggesting that E(2) suppresses NFkappaB signaling by the inactivation of p38 MAPK signaling. LPS promotes VSMCs migration and this is abrogated by MCP-1 antibody, implying that MCP-1 may play a major role as an autocrine factor in atherosclerosis. In addition, E(2) inhibits LPS-promoted cell migration by downregulation of MCP-1 production. Overall, our results demonstrate that E(2) exerts anti-inflammatory property antagonistic to LPS in VSMCs by reducing MCP-1 production, and this effect is related to the inhibition of p38 MAPK/NFkappaB cascade.
Journal of Molecular Endocrinology 08/2010; 45(2):87-97. · 3.48 Impact Factor
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ABSTRACT: Genistein (GST) is a phytoestrogen that binds estrogen receptors (ER) to produce a protective cardiovascular effect. It also has been shown binding peroxisome proliferator-activated receptor-gamma (PPAR-gamma).
In the present study, we assessed the role of PPAR-gamma and ER in GST-mediated regulation of vascular tone in female rat aortas by in vitro tension measurement, immunohistochemistry, immunofluorescence, immunoprecipitation and Western blot analysis.
In aortas pretreated with GW9662 (inhibitor of PPAR-gamma), ICI182780 (inhibitor of ER) and a combination of GW9662 and ICI182780, the magnitudes of GST-induced dilatation were attenuated. N(G)-nitro-L-arginine methyl ester had a similar effect. ER-beta and PPAR-gamma colocalized in all 3 layers of the aortas, while ER-alpha and PPAR-gamma colocalized only in the vascular endothelium and adventitia. In GST-treated whole-cell protein samples, we demonstrated coimmunoprecipitation of ER-beta (not ER-alpha) and PPAR-gamma. The expression of ER-beta and PPAR-gamma in nuclear protein from GST-treated samples increased, which was partially reversed by either GW9662 or ICI182780 and more efficiently reversed using a combination of GW9662 and ICI182780.
Our findings suggest that GST can relax phenylephrine-induced vascular contraction in female rat aortas, which is mediated by PPAR-gamma and ER-beta.
Pharmacology 01/2010; 86(2):117-24. · 1.79 Impact Factor
