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The Synthetic Steroid Tibolone Decreases Reactive Gliosis and Neuronal Death in the Cerebral Cortex of Female Mice After a Stab Wound Injury. Mol Neurobiol 2018; 55:8651-8667. [PMID: 29582398 DOI: 10.1007/s12035-018-1008-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/15/2018] [Indexed: 02/07/2023]
Abstract
Previous studies have shown that estradiol reduces reactive gliosis after a stab wound injury in the cerebral cortex. Since the therapeutic use of estradiol is limited by its peripheral hormonal effects, it is of interest to determine whether synthetic estrogenic compounds with tissue-specific actions regulate reactive gliosis. Tibolone is a synthetic steroid that is widely used for the treatment of climacteric symptoms and/or the prevention of osteoporosis. In this study, we have assessed the effect of tibolone on reactive gliosis in the cerebral cortex after a stab wound brain injury in ovariectomized adult female mice. By 7 days after brain injury, tibolone reduced the number of glial fibrillary acidic protein (GFAP) immunoreactive astrocytes, the number of ionized calcium binding adaptor molecule 1 (Iba1) immunoreactive microglia, and the number of microglial cells with a reactive phenotype in comparison to vehicle-injected animals. These effects on gliosis were associated with a reduction in neuronal loss in the proximity to the wound, suggesting that tibolone exerts beneficial homeostatic actions in the cerebral cortex after an acute brain injury.
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Spilioti E, Holmbom B, Papavassiliou AG, Moutsatsou P. Lignans 7-hydroxymatairesinol and 7-hydroxymatairesinol 2 exhibit anti-inflammatory activity in human aortic endothelial cells. Mol Nutr Food Res 2013; 58:749-59. [PMID: 24311533 DOI: 10.1002/mnfr.201300318] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 09/10/2013] [Accepted: 09/16/2013] [Indexed: 12/15/2022]
Abstract
SCOPE In the present study, we evaluated the anti-inflammatory properties of several plant lignans most commonly distributed in foods. 7-Hydroxymatairesinol (HMR) and its major isomer 7-hydroxymatairesinol 2 (HMR2), lariciresinol, secoisolariciresinol, and pinoresinol, isolated from Norway spruce knots were examined. METHODS AND RESULTS We investigated the anti-inflammatory effects of lignans on tumor necrosis factor-α-treated human aortic endothelial cells by measuring the expression of intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 by cell ELISA and the adhesion of U937 monocytes to activated endothelial cells using a cell adhesion assay. Among the lignans studied, HMR and HMR2 significantly reduced intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 levels as well as the adhesion of U937 to endothelial cells. To further characterize the molecular mechanisms involved in this regulation, the effect of HMR and HMR2 on nuclear factor-κB, SAPK/c-Jun NH2-terminal kinase and extracellular signal regulated kinase phosphorylation was assessed. CONCLUSION Our results demonstrated that the lignans HMR and HMR2, dominant in cereals such as in wheat, triticale, oat, barley, millet, corn bran, and in amaranth whole grain, exhibit strong anti-inflammatory properties in endothelial cells, at least in part, through attenuation of nuclear factor-κB and extracellular signal regulated kinase phosphorylation.
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Affiliation(s)
- Eliana Spilioti
- Department of Biological Chemistry, Medical School, University of Athens, Athens, Greece
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Yang PY, Tang CC, Chang YC, Huang SY, Hsieh SP, Fan SS, Lee HP, Lin SC, Chen WF, Wen ZH, Jean YH. Effects of tibolone on osteoarthritis in ovariectomized rats: association with nociceptive pain behaviour. Eur J Pain 2013; 18:680-90. [PMID: 24151039 DOI: 10.1002/j.1532-2149.2013.00406.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2013] [Indexed: 11/07/2022]
Abstract
BACKGROUND To investigate the role of the synthetic steroid tibolone in the progression of osteoarthritis (OA) and in nociceptive behaviour in an experimental rat model of OA and ovariectomy (OVX)-induced osteoporosis. METHODS OA was induced in Wistar rats by anterior cruciate ligament transection (ACLT) of the right knee. Osteoporosis was induced by bilateral OVX. Groups of animals were subjected to ACLT, OVX, sham or OVX + ACLT. In addition, two groups were subjected to OVX + ACLT surgeries and were orally administered 0.1 or 0.5 mg tibolone every other day for 14 consecutive weeks, starting 6 weeks after surgery. Nociceptive behaviours (secondary mechanical allodynia and weight-bearing distribution of the hind paws) were analysed prior to and every 3 weeks after surgery up to 24 weeks. At 24 weeks, histopathological studies were performed on the cartilage and synovial membranes of the knee joints, and bone metabolism was assessed by measuring serum concentrations of calcium, phosphorus and alkaline phosphatase. RESULTS Rats undergoing ACLT or OVX + ACLT surgeries showed obvious OA changes in the joints. Animals subjected to ACLT + OVX and treated with tibolone had significantly less cartilage degeneration and synovitis and showed improved nociceptive tests compared with animals undergoing ACLT + OVX surgeries alone. OVX increased the severity of the ACLT-induced OA changes. There was a significant increase in serum alkaline phosphatase in the tibolone-treated ACLT + OVX groups. CONCLUSIONS Treatment with tibolone attenuated the development of OA, concomitantly reduced nociception and increased serum alkaline phosphatase in ACLT + OVX rats.
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Affiliation(s)
- P-Y Yang
- Department of Obstetrics and Gynecoloy, Changhua Christian Hospital, Pingtung, Taiwan
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Andrade CMD, Sá MFSD, Toloi MRT. Effects of phytoestrogens derived from soy bean on expression of adhesion molecules on HUVEC. Climacteric 2012; 15:186-94. [PMID: 22066752 DOI: 10.3109/13697137.2011.582970] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The risks of hormone replacement therapy have led to a search for new alternatives such as phytoestrogens, plant compounds with estrogen-like biological activity. Isoflavones are the phytoestrogens most extensively studied and can be found in soybean, red clover and other plants. Due to this estrogen-like activity, phytoestrogens can have some effect on atherosclerosis. Human umbilical vein endothelial cells (HUVEC) have been extensively used to study the biology and pathobiology of human endothelial cells and most of the knowledge acquired is due to experiments with cultures of these cells. OBJECTIVE To evaluate the effects of the phytoestrogen extracts from Glycine max soy bean, genistein, formononetin, biochanin A and daidzein, as well as a mixture of these extracts (Mix), on expression of adhesion molecules, VCAM-1, ICAM-1 and E-selectin, by endothelial cell HUVEC, stimulated with lipopolysaccharide. METHODS HUVEC were cultured in medium EBM(2), pretreated with isoflavones for 24 and 48 h and then stimulated with lipopolysaccharide; in addition, isoflavones were added, after stimulation by lipopolysaccharide, to HUVEC. We evaluated the production of VCAM-1, ICAM-1 and E-selectin on cell surface, by cell-based enzyme immunoassay, and of sVCAM-1, sICAM-1 and sE-selectin in culture supernatant, by ELISA. RESULTS Genistein, formononetin, biochanin A and daidzein, as well as the Mix were able to reduce VCAM-1, ICAM-1 and E-selectin on cell surface and in culture supernatant. Conclusion Isoflavones extracted from Glycine max soy bean, in vitro, presented antiatherogenic effects, reducing the expression of adhesion molecules and acting as preventive agents as well as therapeutic agents.
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Affiliation(s)
- C M de Andrade
- Department of Clinical, Toxicological and Bromatological Analysis, Ribeirão Preto School of Pharmaceutical Sciences, University of São Paulo, Av. Bandeirantes s/n, Monte Alegre, Ribeirão Preto, São Paulo, Brazil
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Biglia N, Maffei S, Lello S, Nappi RE. Tibolone in postmenopausal women: a review based on recent randomised controlled clinical trials. Gynecol Endocrinol 2010; 26:804-14. [PMID: 20586550 DOI: 10.3109/09513590.2010.495437] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIM To critically discuss the use of tibolone (T), in light of a series of very recent double-blind placebo (PL) controlled trials (LISA, LIFT, OPAL, THEBES, LIBERATE) conducted worldwide in a large number of postmenopausal women (PMW). METHODS The most relevant publications on T therapy in PMW were considered with emphasis on menopausal symptoms, quality of life, sexuality, bone, cardiovascular system (CVS) and oncologic risk. RESULTS T significantly relieves climacteric symptoms and improves mood and sexual well-being (LISA). T is as effective as estrogen-progestin therapy in preventing bone loss and reducing the relative risk of vertebral and non-vertebral fractures (LIFT). By using surrogate endpoints of the individual risks for the CVS, studies show mixed results, but a favourable effect on acute miocardial infarction and thromboembolism has been documented (THEBES, LIFT, OPAL). Although findings about endometrial and colon cancer are reassuring, conclusive data on breast cancer risk with T are not available and an increased risk of recurrence in women with previous breast cancer emerged (LIBERATE). CONCLUSIONS T is effective in treating menopausal syndrome with a good tolerability profile. In spite of some unsolved issues in term of safety, T is still a good treatment option for early PMW.
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Affiliation(s)
- Nicoletta Biglia
- Gynecological Oncology Department, University of Turin, Mauriziano Umberto I Hospital, Turin, Italy
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Seeger H, Kloosterboer HJ, Studen M, Wallwiener D, Mueck AO. In vitro effects of tibolone and its metabolites on human vascular coronary cells. Maturitas 2007; 58:42-9. [PMID: 17572028 DOI: 10.1016/j.maturitas.2007.04.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 04/03/2007] [Accepted: 04/29/2007] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Tibolone is a tissue selective compound with estrogenic, androgenic and progestogenic properties in classical bioassays. It is used for alleviation of menopausal symptoms and for osteoporosis prophylaxis in postmenopausal women. Only few data are available regarding the effects of tibolone on the cardiovascular system. We investigated therefore the in vitro effects of tibolone and its metabolites on the vasculature under special controlled conditions, using human female coronary endothelial and smooth muscle cells. METHODS The effect on the production of the following markers in endothelial cells from human female coronary arteries was evaluated: nitric oxide synthase, prostacyclin, endothelin, plasminogen-activator-inhibitor-1 (PAI-1), E-Selectin, Intercellular adhesion molecule (ICAM-1), monocyte attracting protein-1 (MCP-1) and the precursor of matrix metalloproteinase-1 (pro-MMP-1). Tibolone, its metabolites, estradiol (E2), E2/norethisterone (NET) and E2/medroxyprogesterone acetate (MPA) were tested at 0.1 microM and 1 microM. The markers were determined by enzyme immunoassays in the cell supernatant. Cell proliferation of smooth muscle cells from female coronary artery was measured by an adenosine triphosphate-assay. RESULTS Tibolone, its 3-hydroxy metabolites, E2/NET, E2/MPA and estradiol alone had significant effects on the synthesis of all markers tested. The magnitude of the tibolone effects, however, was mostly smaller than that of E2/NET and E2/MPA. Concerning smooth muscle cells tibolone and its 3-hydroxy metabolites also elicited an inhibition of the proliferation compared to control values. The strongest effect here was found for E2/NET and E2 alone, whereas E2/MPA had no effect. CONCLUSION The results of this in vitro study conducted with cells of the most important vascular bed with respect to the problem of cardiovascular risk suggest that tibolone can positively influence the vasculature. However, these tibolone effects may depend on intact vascular cells and may vary due to the different atherosclerotic stages of the vessels. Thus, experimental studies are useful to explore mechanisms, but clearly cannot replace clinical studies.
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MESH Headings
- Biomarkers/blood
- Cells, Cultured
- Coronary Vessels/cytology
- Coronary Vessels/drug effects
- E-Selectin/blood
- Endothelins/blood
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Enzyme-Linked Immunosorbent Assay
- Epoprostenol/blood
- Estradiol/pharmacology
- Female
- Humans
- Intercellular Adhesion Molecule-1/blood
- Matrix Metalloproteinase 1/blood
- Medroxyprogesterone Acetate/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nitric Oxide Synthase/blood
- Norethindrone/pharmacology
- Norpregnenes/pharmacology
- Plasminogen Activator Inhibitor 1/blood
- Vascular Resistance/drug effects
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Affiliation(s)
- H Seeger
- Department of Endocrinology and Menopause, University's Women Hospital, Calwerstrasse 7, 72 076 Tuebingen, Germany
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Campisi R, Marengo FD. Cardiovascular Effects of Tibolone: A Selective Tissue Estrogenic Activity Regulator. ACTA ACUST UNITED AC 2007; 25:132-45. [PMID: 17614936 DOI: 10.1111/j.1527-3466.2007.00007.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Traditionally, it was accepted that long-term hormone replacement therapy (HRT) has a cardiovascular beneficial effect in postmenopausal women with and without coronary artery disease (CAD). However, randomized trials in postmenopausal women have not shown any benefit in either primary or secondary prevention of cardiovascular events. Therefore, these findings have raised the question of whether traditional HRT (i.e., estrogen and progesterone) has a cardioprotective effect in women at risk for or with established CAD. Concerns about the use of conventional HRT have led to a search for alternatives. Tibolone is a synthetic compound with estrogenic, androgenic, and progestogenic properties that relieves climacteric symptoms and prevents postmenopausal bone loss. Tibolone possesses a tissue-selective mechanism of action that differs from that of estrogen and/or progestogen. Unlike these compounds, tibolone's metabolites play a central role in its mode of action. Tibolone is widely used for HRT. However, its clinical impact on cardiovascular disease is still under study. The current review focuses on the effects of tibolone on the cardiovascular system and discusses clinical investigations with this compound in postmenopausal women.
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Affiliation(s)
- Roxana Campisi
- Fundación Centro Diagnóstico Nuclear and Instituto Argentino de Diagnóstico y Tratamiento S.A., Argentina.
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Simoncini T, Mannella P, Genazzani AR. Rapid Estrogen Actions in the Cardiovascular System. Ann N Y Acad Sci 2006; 1089:424-30. [PMID: 17261785 DOI: 10.1196/annals.1386.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the last two decades, several studies have unveiled a series of original signaling mechanisms through which so-called "nuclear" receptors can mediate rapid actions of steroid hormones. These rapid signaling actions are independent of the synthesis of mRNA or protein, and are therefore known as "nontranscriptional" or "nongenomic" as opposed to the classical genomic mechanisms. Nongenomic signaling of estrogens plays a prominent role in nonreproductive tissues, and between these is the vascular wall. At this level, estrogen triggers rapid vasodilatation, exerts anti-inflammatory effects, stimulates endothelial growth and migration, and protects the vessels from atherosclerotic degeneration. Nongenomic signaling mechanisms have been involved in many of these actions and are increasingly considered to be of importance for vascular function in physiological and pathophysiological conditions. Rapid actions of steroid hormones have been implicated with vascular as well as with myocardial protection in animal experimental models. Moreover, the nongenomic signaling of estrogens is tightly interconnected with the nuclear pathways, and there are several indications that, through nongenomic modulation of signaling cascades, estrogens are also able to modulate the expression of several relevant genes in endothelial cells. In conclusion, while we are still in an early phase of the investigations of the nontranscriptional actions of steroid hormone receptors, it is clear that this newly recognized category of signaling mechanisms is responsible for critical steroid actions in nonreproductive tissues.
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Affiliation(s)
- Tommaso Simoncini
- Molecular and Cellular Gynecological Endocrinology Laboratory (MCGEL), Department of Reproductive Medicine and Child Development, Division of Gynecology and Obstetrics, University of Pisa, 56100 Pisa, Italy.
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Cicinelli E, Ranieri G, Maffei S, Colafiglio G, Ria R, Bellavia M, Schonauer MM. Long-term effects of tibolone on circulating levels of vascular cell adhesion molecules and E-selectin in postmenopausal women. Fertil Steril 2006; 86:899-904. [PMID: 16963035 DOI: 10.1016/j.fertnstert.2006.03.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 03/13/2006] [Accepted: 03/13/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Adherence of lymphocytes and monocytes to cell adhesion molecules (vascular cell adhesion molecules [VCAMs]) expressed by activated endothelial cells is the first step in the development of atherosclerotic disease. It is known that administration of tibolone for 8 weeks reduces serum levels of VCAMs in postmenopausal women. We evaluated the effects of the administration of tibolone in postmenopausal women for 1 year. DESIGN Randomized, placebo-controlled, crossover trial. SETTING Healthy volunteers in an academic environment. PATIENT(S) Thirty-six healthy women in postmenopause since 1-4 years. INTERVENTION(S) Group A received 2.5 mg/d of tibolone and group B received placebo for 12 months; treatment was subsequently crossed over for 1 month. MAIN OUTCOME MEASURE(S) Serum concentrations of VCAM-1, intercellular adhesion molecule-1 (ICAM-1), and E-selectin were evaluated at baseline and at 6, 12, and 13 months. RESULT(S) Baseline concentration of VCAM-1, ICAM-1, and E-selectin were similar in both groups. At months 6 and 12, mean concentrations of VCAM-1, ICAM-1, and E-selectin decreased significantly in group A but not in group B. At month 13, levels returned to baseline in group A, whereas they decreased significantly in group B. CONCLUSION(S) Tibolone causes a rapid and sustained decrease in circulating levels of VCAMs; the effect is lost soon after stopping the treatment. Tibolone induces favorable changes in endothelial function and may exert a direct cardiovascular protective effect in postmenopausal women.
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Affiliation(s)
- Ettore Cicinelli
- Department of Obstetrics and Gynecology, Section of Internal Medicine, University of Bari, Bari, Italy.
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Sator K, Sator MO, Sator PG, Egarter C, Huber JC. Effects of tibolone on selectins in postmenopausal women. Maturitas 2006; 53:166-70. [PMID: 15894441 DOI: 10.1016/j.maturitas.2005.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Revised: 03/22/2005] [Accepted: 03/30/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The first step in atherosclerosis is characterized by the adherence of lymphocytes and monocytes to cell adhesion molecules expressed by endothelial cells. The precise mechanism by which steroid hormones may be exerting a protective action against atherogenesis remains unclear. Therefore, we wanted to investigate the effect of tibolone on the circulating levels of various selectins in postmenopausal women. METHODS Thirty healthy postmenopausal women were enrolled in a prospective, randomized, double blind, placebo-controlled outpatient trial. RESULTS Patients treated with tibolone revealed a significant decrease for the variables sE-selectin, sL-selectin, and sPECAM-1 after 8 weeks of treatment. CONCLUSIONS By reducing leukocyte adhesion molecule expression on human endothelial cells, tibolone may have the intrinsic potential to exert additional, lipid-independent, cardiovascular protective effects that may explain the clinical benefits of cardiovascular diseases in postmenopausal women.
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Affiliation(s)
- Kathrin Sator
- Department of Obstetrics and Gynaecology, Division of Endocrinology & Reproductive Medicine, University of Vienna, General Hospital, Waehringer, Austria
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Kiran H, Kiran G. Short-term effects of hormone therapy on serum C-reactive protein levels in postmenopausal women. Arch Gynecol Obstet 2005; 274:9-12. [PMID: 16369811 DOI: 10.1007/s00404-005-0111-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Accepted: 11/16/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the effects of tibolone and conjugated equine estrogens (CEEs) plus medroxyprogesterone acetate (MPA) (CEE + MPA) on levels of serum C-reactive protein (CRP), an independent risk factor for cardiovascular disorders, in postmenopausal women. STUDY DESIGN In this prospective randomized study, we randomly assigned 58 healthy postmenopausal women to CEE (0.625 mg/day) plus MPA (2.5 mg/day) (CEE + MPA) or tibolone (2.5 mg/day). The serum levels of CRP at 3 months after starting treatment were compared with baseline values for both therapies. RESULTS After 3 months of treatment the median CRP levels increased by 29% in the CEE + MPA group and by 5% in the tibolone group. But, these changes did not have statistical significance (P=0.15, P=0.06, respectively). CONCLUSIONS Our findings show that neither tibolone nor CEE + MPA caused significant changes in serum CRP levels in postmenopausal women. The potential impact of hormone therapy on serum CRP levels should be investigated in ongoing clinical trials.
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Affiliation(s)
- Hakan Kiran
- Prof. Dr. M. Turan Cetin Women HeaIth and IVF Center, 100.yil Mah.132.Sk.No:1 CarrefourSA yani, 01104, Adana, Turkey.
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Koh KK, Han SH, Shin MS, Ahn JY, Lee Y, Shin EK. Significant differential effects of lower doses of hormone therapy or tibolone on markers of cardiovascular disease in post-menopausal women: a randomized, double-blind, crossover study. Eur Heart J 2005; 26:1362-8. [PMID: 15872028 DOI: 10.1093/eurheartj/ehi311] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
AIMS We have previously reported that lower doses of hormone therapy (L-HT) and tibolone have different effects on markers of cardiovascular disease when compared with conventional doses of HT. The objective was to compare the effects of L-HT and tibolone on lipid profile, vasodilation, and factors associated with inflammation and haemostasis. METHODS AND RESULTS Forty-one women received a combination of micronized progesterone 100 mg with conjugated equine estrogen 0.3 mg vs. tibolone 2.5 mg alone daily in random order during 2 months with 2 months washout period. When compared with L-HT, tibolone significantly reduced total cholesterol (P<0.001), triglyceride (P<0.001), HDL cholesterol (P<0.001) levels, and triglyceride/HDL cholesterol ratios (P=0.004) except total cholesterol/HDL cholesterol ratios. Tibolone improved flow-mediated response to hyperaemia from baseline values (P<0.001) by a similar magnitude to L-HT. L-HT and tibolone did not increase high-sensitivity C-reactive protein relative to baseline values. L-HT reduced antithrombin III from baseline values (P=0.037), compared with tibolone showing no changes. However, there was no difference between either. In contrast, tibolone increased pro-thrombin fragment 1+2 (F1+2) from baseline values (P=0.002), compared with L-HT showing no changes. Tibolone significantly reduced plasma plasminogen activator inhibitor type 1 (PAI-1) antigen levels from baseline values (P=0.004), compared with L-HT showing no changes. The effects of L-HT and tibolone on F1+2 and PAI-1 were significantly different (P=0.045 and P=0.008, respectively). CONCLUSION Both tibolone and L-HT improved flow-mediated response by a similar magnitude and did not significantly increase high-sensitivity C-reactive protein. However, tibolone significantly reduced PAI-1, but increased F1+2 more than L-HT.
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Affiliation(s)
- Kwang Kon Koh
- Division of Cardiology, Gil Heart Center, Gachon Medical School, 1198 Kuwol-dong, Namdong-gu, Incheon 405-760, Korea.
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Vogelvang TE, van der Mooren MJ, Mijatovic V. Hormone replacement therapy, selective estrogen receptor modulators, and tissue-specific compounds: cardiovascular effects and clinical implications. ACTA ACUST UNITED AC 2005; 3:105-15. [PMID: 15743106 DOI: 10.2165/00024677-200403020-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In industrialized countries, coronary heart disease (CHD) is not only the leading cause of death in women but of disability as well. Menopause, regardless of age at onset, is associated with a marked increase in CHD risk. Based on epidemiologic studies demonstrating mainly positive biologic effects of hormone replacement therapy (HRT) on CHD risk factors and outcomes, earlier recommendations decreed that most, if not all, postmenopausal women should be treated with long-term HRT. Recent randomized controlled trials with clinical CHD endpoints have shown that previously held dicta may not be accurate. Selective estrogen receptor modulators (SERMs) such as tamoxifen and raloxifene are alternatives to HRT. SERMs represent a growing class of compounds that act as either estrogen receptor agonists or antagonists in a tissue-selective manner. This pharmacologic profile may offer the opportunity to dissociate favorable cardiovascular effects of estrogen from unfavorable stimulatory effects on the breast and endometrium. The only data available regarding the effects of tamoxifen on cardiovascular events in postmenopausal women are from breast cancer trials. They showed fewer fatal myocardial events in women randomly assigned to tamoxifen compared with women assigned to placebo. Raloxifene is a so-called second-generation SERM. It seems clear that raloxifene increases bone mineral density, has no effect on the endometrium, and holds high promise for the prevention of breast cancer. The effect of raloxifene on cardiovascular disease is uncertain. On the basis of the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, raloxifene may offer some protection to women with cardiovascular disease or to those who are at high risk. Proof that raloxifene reduces the risk of CHD requires a clinical trial with hard clinical endpoints. Such a study is currently underway. Clinical trials have demonstrated that the synthetic 19-nortestosterone derivative tibolone reduces climacteric complaints and prevent osteoporosis without causing menstrual bleeding. Tibolone lowers lipoprotein(a), fibrinogen, and plasminogen activator inhibitor-1 levels and improves glucose tolerance, insulin sensitivity, and endothelial function; however, it also lowers high-density lipoprotein cholesterol by >20%. The long-term impact of tibolone on the risk of CHD is not known and needs to be studied.
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Affiliation(s)
- Tatjana E Vogelvang
- Department of Obstetrics and Gynecology, Project Aging Women and the Institute for Cardiovascular Research-Vrije Universiteit, VU University Medical Center, Amsterdam, The Netherlands.
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Kloosterboer HJ. Tissue-selective effects of tibolone on the breast. Maturitas 2004; 49:S5-S15. [PMID: 15351102 DOI: 10.1016/j.maturitas.2004.06.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 05/05/2004] [Accepted: 06/10/2004] [Indexed: 11/21/2022]
Abstract
Hormone treatment with an estrogen plus a progestagen (EPT) increases the risk of breast cancer. Both hormone activities are also induced by tibolone. In order to assess the breast safety of tibolone, it was evaluated in several pre-clinical models. The effects were inconclusive in breast cancer cell lines but, in various in vivo models, it did not stimulate the breast. In the 17,12-dimethylbenz(a)anthracene (DMBA) model, tibolone clearly inhibited the growth of breast tumors and, when given prophylactally, far less tumors developed. Ovariectomized monkeys showed no increase in the expression of the proliferation marker Ki67. The effects of tibolone and its metabolites on the steroid metabolizing enzymes in breast tissues were investigated in order to unravel its mode of action in the breast. Tibolone and its metabolites did not inhibit aromatase, but sulfatase was profoundly inhibited. The sulfated 3alpha-OH tibolone metabolite even showed irreversible inhibition of sulfatase. In addition, 17ss-hydroxysteroid dehydrogenase activities were slightly inhibited and sulfotransferase activity was stimulated at low concentrations. The consequence of these effects is that, for both endogenous estrogens and estrogenic-metabolites of tibolone, the equilibrium is preferential for the sulfated forms. The intracellular hormonal milieu tibolone and its metabolites also influence cellular homeostasis. It inhibits cell proliferation of normal breast epithelial cells and stimulates apoptosis. In this respect, tibolone behaves differently from estrogens. Clinical studies have shown that tibolone users experience less breast tenderness and do not show an increase in mammographic density as found with continuous combined EPT. The data concerning tibolone and breast cancer risk are inconclusive and require further investigation.
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Affiliation(s)
- H J Kloosterboer
- N.V. Organon (Room KA5020), PO Box 20, 5340 BH Oss, The Netherlands.
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Simoncini T, Mannella P, Fornari L, Caruso A, Varone G, Garibaldi S, Genazzani AR. Tibolone activates nitric oxide synthesis in human endothelial cells. J Clin Endocrinol Metab 2004; 89:4594-600. [PMID: 15356068 DOI: 10.1210/jc.2003-032189] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
After the unexpected findings of the Women's Health Initiative trial, indicating that traditional cardiovascular risk markers fail to predict the effects of hormone replacement therapy, it is of interest to characterize how steroids act on vascular cells. This is particularly important for tissue-specific drugs such as tibolone, whose actions may differ from other preparations. Because nitric oxide (NO) is a key regulator of vascular tone and atherogenesis, we studied its regulation by tibolone and its metabolites on human endothelial cells. Tibolone and its estrogenic metabolites (3alpha- and 3beta-OH tibolone) activate NO synthesis by recruiting functional estrogen receptors, whereas the progestogenic/androgenic metabolite (Delta(4) isomer) has no effect. During prolonged exposures, tibolone and the estrogenic compounds enhance the expression of endothelial NO synthase (eNOS). In addition, tibolone is able to induce rapid activation of eNOS, leading to rapid increases in the release of NO. Relevant for its clinical effects, the sulfated metabolites of tibolone are also effective in activating eNOS. Different from estrogen, rapid activation of eNOS does not rely on recruitment of phosphatidylinositol-3 kinase but rather on MAPK-dependent cascades. These results help to understand the mechanisms of action of tibolone on the cardiovascular system and have relevant clinical implications.
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Affiliation(s)
- Tommaso Simoncini
- Molecular and Cellular Gynecological Endocrinology Laboratory, Department of Reproductive Medicine and Child Development, Division of Obstetrics and Gynecology, University of Pisa, Via Roma, 57, 56100 Pisa, Italy.
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16
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Abstract
Tibolone is effective in preventing bone loss and treating climacteric symptoms, without stimulating the endometrium. The effects on bone, brain and vagina can be accurately explained by the oestrogenic activity of tibolone, but oestrogenic activity is not expressed in the endometrium. Tibolone behaves differently from oestrogen plus progestogen combinations on the breast. Therefore, tibolone can be characterised as a selective oestrogen activity regulator. The objective of this review is to characterise the typical properties of tibolone in order to explain its tissue-selective action. Tibolone is rapidly converted into three major metabolites: 3 alpha- and 3 beta-hydroxy-tibolone, which have oestrogenic effects, and the Delta(4)-isomer, which has progestogenic and androgenic effects. The 3-hydroxy metabolites are present in the circulation, predominantly in their inactive sulphated form. The tissue-selective effects of tibolone are the result of metabolism, enzyme regulation and receptor activation that vary in different tissues. The bone preserving effects are the result of oestradiol receptor activation, whilst other steroid receptors, notably the progesterone and androgen receptor, are not involved. Breast tissue of monkeys is not stimulated, as occurs with oestrogen plus progestogen, because tibolone and its metabolites inhibit sulphatase and 17 beta-hydroxysteroid dehydrogenase (HSD) type I and stimulate sulphotransferase and 17 beta-HSD type II, the combined effects of which prevent conversion to active oestrogens. In addition, tibolone affects cellular homeostasis in the breast by inhibiting proliferation and stimulating apoptosis. Tibolone does not stimulate the endometrium because of the action of the highly stable progestogenic metabolite (Delta(4)-isomer) in combination with an effect on the sulphatase (inhibition)-sulphotransferase (stimulation) system. The oestrogenic metabolites of tibolone have direct favourable effects on the cardiovascular system and, in in vivo models, tibolone has shown no adverse consequences. In conclusion, tibolone shows oestrogenic effects in brain, vagina and bone and has direct oestrogenic effects on the cardiovascular system. In the endometrium, the progestogenic activity of the Delta(4)-metabolite and the effect on oestrogen-inactivating enzymes prevent oestrogenic stimulation. The mammary gland is not stimulated in currently used animal models. Tibolone appears to regulate estrogenic activity in the various tissues by influencing the availability of estrogenic compounds for the estradiol receptor in a tissue-selective manner.
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Affiliation(s)
- Helenius J Kloosterboer
- NV Organon, Research and Development Laboratories, P.O. Box 20, Oss 5340 BH, The Netherlands.
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Kalogeropoulos S, Petrogiannopoulos C, Gagos S, Kampas N, Kalogeropoulos G. The influence of 5-year therapy with tibolone on the lipid profile in postmenopausal women with mild hypercholesterolemia. Gynecol Endocrinol 2004; 18:227-32. [PMID: 15293895 DOI: 10.1080/09513590410001667238] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Our objective was to investigate the effects of 5-year therapy with tibolone on the lipid profile in postmenopausal women with mild hypercholesterolemia (total cholesterol, 241 +/- 7 mg/dl; LDL cholesterol, 153 +/- 9 mg/dl). Eighty-two patients were divided into two groups. Group A (53 women) received 2.5 mg of tibolone per day. Group B (29 women) received no tibolone. Total, low- and high-density lipoprotein cholesterol and lipoprotein(a) were found to be decreased in the tibolone group, by 17.7%, 32%, 15.5% and 12%, respectively (p < 0.01) throughout the 5-year treatment, while triglycerides showed no significant change. The lipid profile in the control group remained at its initial values. Menopausal symptoms disappeared in the treatment group within the first 5 months, whereas they deteriorated in the control group during the first 2 years. Although a few unwanted side-effects on hormone-dependent tissues were observed (including vaginal spotting in 11.3% and febrile hemorrhagic cystic mastopathy in 3.8%) long-term therapy with tibolone seemed to be well tolerated, and appeared to have a beneficial effect on the levels of serum lipids.
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Liew R, Stagg MA, MacLeod KT, Collins P. Acute actions of 3α-hydroxy-tibolone on factors influencing contraction in guinea-pig ventricular myocytes. Eur J Pharmacol 2004; 484:141-5. [PMID: 14744597 DOI: 10.1016/j.ejphar.2003.11.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We investigated whether one of the main estrogenic metabolites of the postmenopausal agent, tibolone (Org OD14), exerts direct cardiac actions in a similar way to 17beta-estradiol. 3alpha-OH-tibolone (40 microM) decreased both cell shortening and Ca2+ transient amplitude of field-stimulated (1 Hz, 37 degrees C) guinea-pig ventricular myocytes. These effects were still observed in cells that had been incubated with the specific estrogen receptor antagonist, ICI 182,780 (C(32)H(47)F(5)O(3)S), suggesting an estrogen receptor-independent mechanism of action. In addition, 3alpha-OH-tibolone inhibited the L-type Ca2+ current and shortened action potential durations (APD). This mechanism may contribute to a potential cardiovascular action of tibolone.
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Affiliation(s)
- Reginald Liew
- Cardiac Medicine, National Heart and Lung Institute, Imperial College London, Dovehouse Street, London SW3 6LY, UK.
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19
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Simoncini T, Mannella P, Fornari L, Caruso A, Varone G, Genazzani AR. In vitro effects of progesterone and progestins on vascular cells. Steroids 2003; 68:831-6. [PMID: 14667975 DOI: 10.1016/j.steroids.2003.08.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The impact of progesterone on the cardiovascular system is relevant, but not as well characterized as the effects of estrogens. The recent early interruption of the conjugated equine estrogens (CEE)-medroxyprogesterone acetate (MPA) arm of the Women's Health Initiative trial, but not of the parallel CEE-only treatment arm, suggesting the possibility of harmful cardiovascular effects of the progestins, boosts the debate on the role of progesterone and progestins on the vascular tree. The data available up to now show the presence of important regulatory effects of progestagens on vascular cells. Additionally, the presence of a progestagen results in diverse modifications of the effects of estrogens, sometimes acting synergically, others being neutral or antagonizing estrogens' effects. Notwithstanding the availability of consistent observations on the functional effects of progestins on the cardiovascular system, the molecular mechanisms of progestins actions on vascular cells have been up to now only scarcely characterized. Novel mechanisms of signal transduction are being discovered for progesterone receptors in different tissues, some of which are independent of gene transcription regulation, and are therefore indicated as "nongenomic." Furthermore, the contribution to signal transduction of co-activators is currently widely investigated, in order to understand the ways to tissue-specificity and to engineer new progesterone receptor modulators. The understanding of the molecular basis of progesterone receptor signaling in vascular tissue is therefore of paramount importance for the development of hormonal agents with an optimal cardiovascular profile.
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Affiliation(s)
- Tommaso Simoncini
- Department of Reproductive Medicine and Child Development, Molecular and Cellular Gynecological Endocrinology Laboratory, Division of Obstetrics and Gynecology, University of Pisa, Via Roma, 67, 56100 Pisa, Italy.
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Abstract
OBJECTIVE The first step in atherosclerosis is characterized by the adherence of lymphocytes and monocytes to cell adhesion molecules expressed by endothelial cells. Therefore, we wanted to investigate the effect of tibolone on the circulating levels of various cell adhesion molecules. DESIGN Thirty postmenopausal women were enrolled in a double-blind, randomized, placebo-controlled outpatient trial. RESULTS Tibolone led to a significant decrease in soluble intercellular adhesion molecule-1, soluble intercellular adhesion molecule-3, and soluble vascular cell adhesion molecule-1, but had no effect on monocyte chemotactic protein-1. CONCLUSIONS The direct favorable effects of tibolone on endothelial cells may explain the clinical benefits of this substance in terms of anti-ischemic effects and osteoporosis prevention.
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Affiliation(s)
- Christian Egarter
- Department of Obstetrics and Gynecology, University of Vienna Medical School, Austria.
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Simoncini T, Fornari L, Mannella P, Varone G, Caruso A, Liao JK, Genazzani AR. Novel non-transcriptional mechanisms for estrogen receptor signaling in the cardiovascular system. Interaction of estrogen receptor alpha with phosphatidylinositol 3-OH kinase. Steroids 2002; 67:935-9. [PMID: 12398989 DOI: 10.1016/s0039-128x(02)00040-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Estrogen receptor (ER) signaling has been, for a long time, associated with transcriptional processes involving nuclear translocation and binding on specific response elements, leading to regulation of target gene expression. However, rapid, non-transcriptional mechanisms of signal transduction through steroid hormone receptors have been identified. These so-called 'non-genomic' effects are independent from gene transcription or protein synthesis and involve steroid-induced modulation of cytoplasmic or cell membrane-bound regulatory proteins. Several biological actions of estrogen have been associated with this type of signaling, and intracellular regulatory cascades such as extracellular signal-regulated kinase/mitogen-activated protein kinases (ERK/MAPK) and tyrosine kinases or the modulation of G-protein-coupled receptors have been shown to be non-transcriptionally recruited by estrogen in diverse tissues. The vascular wall is one of these sites, where estrogen triggers rapid vasodilatation mainly due to increased nitric oxide (NO) release. We have recently described a novel, non-transcriptional mechanism for ER signaling in human as well as in animal endothelial cells, showing that ER alpha can physically and functionally couple to the lipid kinase phosphatidylinositol 3-OH kinase (PI3K). This interaction leads to activation of PI3K signaling cascade to Ser/Thr kinase Akt, which mediates several PI3K-dependent intracellular effects, including endothelial isoform of NO synthase (eNOS) phosphorylation and activation. This original non-transcriptional mechanism for ER signaling may play an important role in the generation of some of the rapid 'non-genomic' effects of estrogen.
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Affiliation(s)
- Tommaso Simoncini
- Division of Obstetrics and Gynecology, University of Pisa, Via Roma, 67, 56100, Pisa, Italy.
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Register TC, Wagner JD, Zhang L, Hall J, Clarkson TB. Effects of tibolone and conventional hormone replacement therapies on arterial and hepatic cholesterol accumulation and on circulating endothelin-1, vascular cell adhesion molecule-1, and E-selectin in surgically menopausal monkeys. Menopause 2002; 9:411-21. [PMID: 12439100 DOI: 10.1097/00042192-200211000-00006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Menopause and aging are associated with a marked increase in the incidence of coronary heart disease as well as reductions in circulating estrogen, progestogen, and androgen levels. The synthetic compound tibolone and its metabolites have estrogenic, progestogenic, and androgenic characteristics. In the present study, we compared the effects of tibolone, estrogen replacement therapy, and estrogen plus progestogen replacement therapy on arterial and hepatic lipid accumulation and on circulating soluble adhesion molecule and endothelin-1 concentrations in surgically postmenopausal cynomolgus monkeys. DESIGN Animals were fed an atherogenic diet for 2 years while receiving either no hormone treatment (control, n = 31) or the following treatments at doses designed to mimic the human dose on a daily caloric intake basis: tibolone at 2.5 mg/day (HiTib, n = 31), tibolone at 0.625 mg/day (LoTib, n = 29), conjugated equine estrogens (CEE) alone at 0.625 mg/day (CEE, n = 29), or CEE plus continuous medroxyprogesterone acetate (MPA) at 2.5 mg MPA/day (CEE + MPA, n = 30). RESULTS Relative to the control group, iliac artery total cholesterol content was not different in the HiTib, LoTib, and CEE + MPA groups but was significantly lower in the group receiving CEE only (P < 0.05). In contrast, hepatic free cholesterol content was reduced in all treatment groups [HiTib (P < 0.01), LoTib (P < 0.05), CEE (P < 0.01), and CEE + MPA (P < 0.05)], whereas hepatic total and esterified cholesterol content were reduced in the HiTib, CEE, and CEE + MPA groups (all P < 0.05). HiTib and CEE groups had lower hepatic triglyceride levels per milligram of protein (P < 0.05). Iliac arterial cholesterol content was highly correlated with hepatic cholesterol content and with previously published histomorphometrically determined coronary artery atherosclerosis, supporting the use of the iliac artery as a surrogate for the coronary artery in the monkey. Circulating levels of soluble vascular cell adhesion molecule-1 were significantly reduced in the HiTib (P < 0.02) and CEE (P < 0.05) groups, whereas soluble E-selectin was reduced in the CEE group only (P < 0.01). Plasma endothelin-1 was significantly reduced in the LoTib (P < 0.05), CEE (P < 0.01), and CEE + MPA (P < 0.01) groups. CONCLUSIONS These results suggest that while tibolone caused marked depression of high-density lipoprotein cholesterol and a resultant twofold increase in the total plasma cholesterol/high-density lipoprotein cholesterol ratio, those effects did not result in exacerbation of iliac artery atherosclerosis, perhaps because of beneficial effects on vascular biology or hepatic metabolism.
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Affiliation(s)
- Thomas C Register
- Comparative Medicine Clinical Research Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Abstract
OBJECTIVE To review published data pertaining to the effects of tibolone on sexual parameters, mood, and cognitive function in postmenopausal women. DESIGN A review of all relevant published, peer-reviewed studies. RESULTS Tibolone is a compound that can be selectively metabolized by individual tissues to its estrogenic, progestogenic, or androgenic metabolites and hence exhibits tissue-specific hormonal effects. Tibolone also lowers sex hormone binding globulin, thus increasing free estradiol and testosterone levels. Tibolone alleviates climacteric vasomotor symptoms and displays a dominant progestogenic effect on the endometrium. Tibolone normalizes the vaginal karyopyknotic and maturation indexes and alleviates symptomatic atrophic vaginitis. Women treated with tibolone report significant reductions in vaginal dryness and dyspareunia, effects that may be secondary to both estrogenic and androgenic actions. Randomized studies indicate tibolone has positive effects on mood compared with placebo and alleviates several adverse mood parameters to a similar extent as conventional hormone replacement therapy. Improved mood is associated with increased plasma beta-endorphin. With respect to cognition, tibolone seems to improve semantic memory but does not significantly improve recognition memory. Tibolone is associated with improvements in sexual function that seem to be greater than those achieved with standard hormone replacement therapy. CONCLUSION Published studies indicate beneficial effects of tibolone on both libido and mood, which otherwise significantly compromise physical, psychological, and social well-being. Hence, tibolone provides another option for menopausal women experiencing loss of libido as part of their symptomatology or who have persistent low libido despite adequate estrogen/progestin replacement therapy.
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Affiliation(s)
- Susan R Davis
- Jean Hailes Foundation, Clayton, Victoria, Australia.
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Villablanca AC, Lewis KA, Rutledge JC. Time- and dose-dependent differential upregulation of three genes by 17 beta-estradiol in endothelial cells. J Appl Physiol (1985) 2002; 92:1064-73. [PMID: 11842041 DOI: 10.1152/japplphysiol.00374.2001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to identify genetic targets in the vasculature for estrogen by profiling genes expressed in female human aortic endothelial cells exposed to various doses of 17 beta-estradiol at differing concentrations and for differing periods of time. Our approach employed a RT-PCR-based cloning strategy of DNA differential display analysis, with differential expression verified by semiquantitative PCR performed with gene-specific primers. A significant increase in mRNA expression in response to 17 beta-estradiol was observed for the following three genes: aldose reductase (3.4-fold), caspase homologue-alpha protein (4.2-fold), and plasminogen activator inhibitor-1 intron e (2.3-fold). For all three upregulated genes, estradiol-induced upregulation occurred with a similar time course and temporally clustered to the first 24 h after hormone treatment. In addition, the effect of estradiol dose on gene expression was consistent and occurred at physiological concentrations. Our results describe previously uncharacterized estradiol-sensitive time- and dose-dependent regulation of genes with potential importance to vascular function in human endothelial cells.
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Affiliation(s)
- Amparo C Villablanca
- Division of Cardiovascular Medicine, University of California, Davis, California 95616-8636, USA.
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Genazzani AR. Controversial issues in climacteric medicine (I) Cardiovascular disease and hormone replacement therapy. International Menopause Society Expert Workshop, 13–16 October 2000, Royal Society of Medicine, London, UK. Maturitas 2001; 38:263-71. [PMID: 11358643 DOI: 10.1016/s0378-5122(01)00183-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- A R Genazzani
- Universita degli Studi di Pisa, Instituto di Clinica Ost/Gin, Piero Fioretti, Via Roma 67, 56100 Pisa, Italy.
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Mijatovic V. Receptor selectivity, enzymes and tissue specificity. Maturitas 2001; 37:147-9. [PMID: 11173175 DOI: 10.1016/s0378-5122(00)00185-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
In postmenopausal women tibolone has proved to prevent bone-loss and relieve climacteric symptoms as effectively as estrogens, but it does not stimulate the endometrium and the breast. This clinical profile strongly suggests that tibolone is a compound with tissue-specific action. Tibolone is quickly metabolized into its main active metabolites, 3alpha and 3beta-OH, which are also present in an inactive, sulphated, form. In addition a Delta4-metabolite is found in circulation. The 3-OH-metabolites bind only to the estrogen receptor while the Delta4-isomer shows affinity only to the progesterone and androgen receptors. Tibolone prevents bone loss in a similar way to estrogens. Studies on bone mass using anti-estrogen, antiprogestin and anti-androgen in combination with tibolone, confirmed the sole involvement of the estradiol receptor. Increases in skin temperature as well as vaginal atrophy can be prevented by tibolone in a similar way to estrogens. Breast safety studies showed that tibolone clearly inhibited the growth of tumors in a DMBA model. In breast cell lines, tibolone profoundly inhibited sulphatase activity and an increase in apoptosis and decrease in cell proliferation was found. The stimulation of the endometrium is prevented by the local formation of the Delta4-isomer from tibolone or the 3beta-OH-metabolite. We conclude that tibolone acts as a tissue-specific compound by mediating its effects via steroid receptors and enzymatic pathways. This dual effect of tibolone explains it's positive clinical effects on bone, vagina and brain, and avoids stimulation of the endometrium and breast tissue.
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Affiliation(s)
- H J Kloosterboer
- NV Organon, Research and Development Laboratories, P.O. Box 20, 5340, Oss, The Netherlands.
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Genazzani AR, Gambacciani M. Controversial issues in climacteric medicine I. Cardiovascular disease and hormone replacement therapy. International Menopause Society Expert Workshop. 13-16 October 2000, royal society of medicine, London, UK. Climacteric 2000; 3:233-40. [PMID: 11910582 DOI: 10.1080/13697130008500127] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The clinical benefits of HRT are clearly established for the relief of menopausal symptoms, improving quality of life and the prevention of osteoporosis. Although research on the impact of HRT (oral, transdermal, tibolone, etc.) and on the effects of raloxifene on CVD is still ongoing, with certain unresolved controversies, studies using a variety of different HRT formulations have shown a clear benefit on surrogate markers of CHD and epidemiological and clinical, although not randomized, studies have demonstrated a CHD reduction in HRT-treated women. Today, HRT may be used for the primary prevention of CVD. Conversely, there is no clear reason to commence HRT solely or primarily to confer an immediate cardiovascular benefit in postmenopausal women with established CHD. Equally, there is no compelling evidence for discontinuing--or indeed not initiating--HRT in women without CVD because of concern about cardiovascular risk. In any case, all medical interventions should be individualized to the specific woman's age, characteristics and needs. The ultimate effects of different dosages, schedules and type of hormones used should be clarified, avoiding inferring the effects of one form of HRT to others. The importance of increased attention to life-style factors such as healthy diet, exercise and cessation of smoking should be underlined since these can confer specific benefits also to menopausal women. For women with known risks for CVD, HRT may contribute to the beneficial effects of life-style improvements and well-established therapies (including blood pressure control, cholesterol-lowering drugs, aspirin, etc.). New strategies, including lower dosages, new estrogens, progestins, and new estrogen-like substances may be designed to target specific needs.
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Affiliation(s)
- A R Genazzani
- Department of Gynecology and Obstetrics, University of Pisa, Via Roma 35, 56126 Pisa, Italy
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