Timing of the vascular actions of estrogens in experimental and human studies: why protective early, and not when delayed?

International audienceEstrogens, and in particular 17β-estradiol (E2), play a pivotal role in sexual development and reproduction and are also implicated in a large number of physiological processes including the cardiovascular system. Although epidemiological studies and Nurses' Health Study suggested, and all animal models of early atheroma clearly demonstrated a vasculoprotective action of both endogenous and exogenous estrogens, the Women's Health Initiative did not confirm the preventive action of estrogens against coronary heart disease (CHD). However, women who initiated hormone therapy closer to menopause tended to have reduced CHD risk compared with increased CHD risk among women more distant from menopause. Thus, it is now mandatory to try to understand the mechanisms that could have influenced the actions of estrogens at various stages of atherosclerosis and/or of life. In this current review, we will summarize our understanding of the potential cellular targets and mechanisms of the vasculoprotective actions of estrogens, as well as of the lack of action of estrogens when administered after a period of hormonal deprivation. The mechanisms of the aggravating role of progestogens such as medroxyprogesterone acetate will be considered. Finally, we will analyze the possibilities to uncouple some beneficial from other undesirable actions following the partial/selective activation of estrogen receptors

Estrogens in vascular biology and disease: where do we stand today?

International audiencePURPOSE OF REVIEW: Whereas hormone therapy may increase the risk of coronary heart disease and stroke in menopausal women, epidemiological studies (protection in premenopausal women) suggest and experimental studies (prevention of fatty streak development in animals) demonstrate a major atheroprotective action of estradiol. There is also evidence for a thrombogenic effect of oral estrogens. An understanding of the deleterious and beneficial effects of estrogens is thus required. RECENT FINDINGS: The immuno-inflammatory system plays a key role in the development of fatty streak deposit as well as in the rupture of the atherosclerotic plaque. Whereas estradiol favors an anti-inflammatory effect in vitro (cultured cells), it rather elicits a pro-inflammatory response in vivo involving several subpopulations of the immuno-inflammatory system, which could contribute to plaque destabilization. Endothelium is another important target for estrogens, since estradiol potentiates endothelial nitric oxide and prostacyclin production. The respective actions of estrogens on these cell populations may be influenced by the timing of hormonal therapy initiation, hormone regimens, status of the vessel wall and expression of isoforms of estrogen receptors alpha and beta. SUMMARY: A better understanding of the balance between the deleterious and beneficial effects of estrogens is required and should help to improve hormonal therapy safety and to optimize the prevention of cardiovascular disease after menopause

Male osteoporosis: diagnosis and fracture risk evaluation.

International audienceMale osteoporosis is challenging to diagnose and to treat. Underestimation of the risk of male osteoporosis, the combined presence of several interwoven causative factors in many patients, and uncertainty regarding the absorptiometry cutoffs associated with fractures are major obstacles to the diagnosis of male osteoporosis and to the identification of men at risk for fractures. The lifetime risk of osteoporotic fracture is estimated at 15% among men older than 50 years. One-third of proximal femoral fractures occur in men, and the associated mortality rate is 2- to 3-fold that in women. In men, nearly half the cases of osteoporosis are related to disease, medications, or risk factors. Although the criteria for diagnosing male osteoporosis are not agreed on, the definitions developed by the World Health Organization can be used provided the reference population is composed of young males. An absorptiometry T-score < or = -2.5 is useful for diagnosing osteoporosis but fails to adequately predict the fracture risk. The identification of men at high risk for fractures requires a combined evaluation of bone mineral density data, clinical risk factors, and risk factors for falls

The TLR-mediated response of plasmacytoid dendritic cells is positively regulated by estradiol in vivo through cell-intrinsic estrogen receptor α signaling.

International audiencePlasmacytoid dendritic cells (pDCs) produce large amounts of type I interferons (IFN-α/β) in response to viral or endogenous nucleic acids through activation of their endosomal Toll-like receptors (TLR-7 and TLR-9). Enhanced TLR-7-mediated IFN-α production by pDCs in women, compared with men, has been reported, but whether sex hormones, such as estrogens, are involved in this sex-based difference is unknown. Here we show, in humanized mice, that the TLR-7-mediated response of human pDCs is increased in female host mice relative to male. In a clinical trial, we establish that treatment of postmenopausal women with 17β-estradiol markedly enhances TLR-7- and TLR-9-dependent production of IFN-α by pDCs stimulated by synthetic ligands or by nucleic acid-containing immune complexes. In mice, we found exogenous and endogenous estrogens to promote the TLR-mediated cytokine secretion by pDCs through hematopoietic expression of estrogen receptor (ER) α. Genetic ablation of ERα gene in the DC lineage abrogated the enhancing effect of 17β-estradiol on their TLR-mediated production of IFN-α, showing that estrogens directly target pDCs in vivo. Our results uncover a previously unappreciated role for estrogens in regulating the innate functions of pDCs, which may account for sex-based differences in autoimmune and infectious diseases

Estradiol administration controls eosinophilia through estrogen receptor-alpha activation during acute peritoneal inflammation.

International audienceEstrogens influence the incidence and the course of numerous immune or inflammatory diseases in humans and in experimental models. For instance, estrogens prevent the accumulation of granulocytes in acute inflammatory murine models, but the respective actions on neutrophil and eosinophil trafficking remain to be clarified. We demonstrate here that in a model of TGC-induced sterile peritonitis in ovx mice, chronic E2 administration electively and strongly inhibited peritoneal eosinophil accumulation. E2 decreased BM eosinophil number, contributing to a marked prevention of the TGC-induced eosinophil blood mobilization. These effects on eosinophil mobilization and peritoneal accumulation were abolished in ER-α(-/-) mice, demonstrating the crucial role of this nuclear receptor. Grafting ER-α(-/-) mice with ER-α(+/+) BM cells restored the suppressive effect of E2 on peritoneal eosinophilia, although the action on eosinophil blood mobilization was still abrogated. We therefore explored additional mechanisms and found that E2 reduced the peritoneal concentrations of key eosinophil prosurvival factors (IL-5, IL-9, and IL-25) and enhanced eosinophil apoptosis during the inflammatory process. Furthermore, this proapoptotic effect of E2 was abrogated in IL-5-overexpressing Tg mice. To conclude, we demonstrate for the first time that ER-α activation by exogenous E2 administration strongly inhibits eosinophil accumulation during acute inflammation in a nonreproductive target site for estrogen through combined actions on eosinophil mobilization and apoptosis. This specific, suppressive effect of chronic E2 replacement therapy on eosinophils has to be integrated to further understand the evolution of eosinophil-associated diseases in menopausal women

Vers une optimisation de la modulation du récepteur des œstrogènes dans le traitement hormonal de la ménopause

Les femmes vivent désormais plus d’un tiers de leur vie après la survenue de la ménopause. Le déclin de la production d’œstrogènes endogènes au cours de cette période s’accompagne fréquemment de troubles fonctionnels qui affectent la qualité de vie. Ces symptômes peuvent être soulagés par un traitement hormonal (THM) initialement fondé sur l’administration d’œstrogènes conjugués équins (principalement aux États-Unis, par voie orale) ou d’un œstrogène naturel, le 17β-estradiol (en Europe, notamment par voie transdermique). Le récepteur des œstrogènes α (REα) relaye la majorité des effets physiologiques des œstrogènes. REα appartient à la superfamille des récepteurs nucléaires. Il régule la transcription de gènes via ses fonctions activatrices (AF1 et AF2). Outre ces actions génomiques classiques, les œstrogènes peuvent aussi activer une sous-population de récepteurs REα présents à la membrane des cellules et ainsi induire des signaux rapides. Dans cette revue, nous résumerons l’évolution des THM depuis les débuts de la substitution hormonale jusqu’aux nouvelles molécules émergentes fondées sur une modulation sélective du REα. Nous décrirons également les progrès récents sur la compréhension des mécanismes d’action des œstrogènes, en détaillant les rôles respectifs des REα nucléaire et membranaire et les développements thérapeutiques possibles qui pourraient en découler

Reimbursment of the serum CTX assay in France: the clinical biology nomenclature is incoherent.

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Trabecular Bone Score: Where are we now?

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Préservation de la fertilité, contraception et traitement hormonal de la ménopause chez les femmes traitées pour tumeurs malignes rares de l’ovaire : recommandations du réseau national dédié aux cancers gynécologiques rares (TMRG/GINECO)

National audienceIntroduction - Rare ovarian tumors include complex borderline ovarian tumors, sex-cord tumors, germ cell tumors, and rare epithelial tumors. Indications and modalities of fertility preservation, infertility management and contraindications for hormonal contraception or menopause hormone therapy are frequent issues in clinical practice. A panel of experts from the French national network dedicated to rare gynaecological cancers, and of experts in reproductive medicine and gynaecology have worked on guidelines about fertility preservation, contraception and menopause hormone therapy in women treated for ovarian rare tumors. Methods - A panel of 39 experts from different specialties contributed to the preparation of the guidelines, following the DELPHI method (formal consensus method). Statements were drafted after a systematic literature review, and then rated through two successive rounds. Results - Thirty-five recommendations were selected, and concerned indications for fertility preservation, contraindications for ovarian stimulation (in the context of fertility preservation or for infertility management), contraceptive options (especially hormonal ones), and menopause hormone therapy for each tumor type. Overall, prudence has been recommended in the case of potentially hormone-sensitive tumors such as sex cord tumors, serous and endometrioid low-grade adenocarcinomas, as well as for high-risk serous borderline ovarian tumors. Discussion - In the context of a scarce literature, a formal consensus method allowed the elaboration of guidelines, which will help clinicians in the management of these patients