17β-Estradiol Promotes TLR4-Triggered Proinflammatory Mediator Production through Direct Estrogen Receptor α Signaling in Macrophages In Vivo

Plasmacytoid 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.

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Neuronal Estrogen Receptor-α Mediates Neuroprotection by 17β-Estradiol

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2009.258 ◽

2009 ◽

Vol 30 (5) ◽

pp. 935-942 ◽

Cited By ~ 48

Author(s):

Joachim G Elzer ◽

Sajjad Muhammad ◽

Tim M Wintermantel ◽

Anne Regnier-Vigouroux ◽

Jochen Ludwig ◽

...

Keyword(s):

Estrogen Receptor ◽

Infarct Volume ◽

Estrogen Receptor Α ◽

Mutant Mice ◽

In Vivo Model ◽

Neuroprotective Effects ◽

In Vivo Models ◽

17Β Estradiol

17β-Estradiol (E2) was shown to exert neuroprotective effects both in in vitro and in vivo models of stroke. Although these effects of E2 are known to require estrogen receptor-α (ERα), the cellular target of estrogen-mediated neuroprotection remains unknown. Using cell type-specific ER mutant mice in an in vivo model of stroke, we specifically investigated the role of ERα in neuronal cells versus its role in the microglia in the mediation of neuroprotection by estrogens. We generated and analyzed two different tissue-specific knockout mouse lines lacking ERα either in cells of myeloid lineage, including microglia, or in the neurons of the forebrain. Both E2-treated and E2-untreated mutant and control mice were subjected to a permanent middle cerebral artery occlusion for 48 h, and the infarct volume was quantified. Although the infarct volume of E2-treated female myeloid-specific ERα knockout mice was similar to that of E2-treated control mice, both male and female neuron-specific ERα mutant mice had larger infarcts than did control mice after E2 treatment. We conclude that neuronal ERα in female and male mice mediates neuroprotective estrogen effects in an in vivo mouse model of stroke, whereas microglial ERα is dispensable.

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Protective Hematopoietic Effect of Estrogens in a Mouse Model of Thrombosis: Respective Roles of Nuclear Versus Membrane Estrogen Receptor α

Endocrinology ◽

10.1210/en.2015-1522 ◽

2015 ◽

Vol 156 (11) ◽

pp. 4293-4301 ◽

Cited By ~ 4

Author(s):

Marie-Cécile Valéra ◽

Coralie Fontaine ◽

Françoise Lenfant ◽

Cendrine Cabou ◽

Maeva Guillaume ◽

...

Keyword(s):

Estrogen Receptor ◽

Estrogen Receptor Alpha ◽

Bleeding Time ◽

Activation Function ◽

Estrogen Receptor Α ◽

Loss Of Function ◽

Antithrombotic Effects ◽

17Β Estradiol ◽

First Time

We recently reported that chronic 17β-estradiol (E2) treatment in mice decreases platelet responsiveness, prolongs the tail-bleeding time and protects against acute thromboembolism via the hematopoietic estrogen receptor alpha (ERα), and independently of ERβ. Here, we have explored the respective roles of membrane vs nuclear actions of ERα in this process, using: 1) the selective activator of membrane ERα: estrogen dendrimer conjugate, and 2) mouse models with mutations in ERα. The selective targeting of activation function 2 of ERα provides a model of nuclear ERα loss-of-function, whereas mutation of the ERα palmitoylation site leads to a model of membrane ERα deficiency. The combination of pharmacological and genetic approaches including hematopoietic chimera mice demonstrated that absence of either membrane or nuclear ERα activation in bone marrow does not prevent the prolongation of the tail-bleeding time, suggesting a redundancy of these two functions for this E2 effect. In addition, although hematopoietic membrane ERα is neither sufficient nor necessary to protect E2-treated mice from collagen/epinephrine-induced thromboembolism, the protection against death-induced thromboembolism is significantly reduced in the absence of hematopoietic nuclear ERα activation. Overall, this study emphasizes that hematopoietic cells (likely megakaryocytes and possibly immune cells) constitute an important target in the antithrombotic effects of estrogens, and delineate for the first time in vivo the respective roles of membrane vs nuclear ERα effects, with a prominent role of the latter.

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The Activation of Plasminogen Activator Inhibitor-1 Expression by IL-1β Is Attenuated by Estrogen in Hepatoblastoma HepG2 Cells Expressing Estrogen Receptor α

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614489 ◽

1999 ◽

Vol 81 (03) ◽

pp. 423-427 ◽

Cited By ~ 11

Author(s):

Marshall Scicchitano ◽

Edward Kilbourne

Keyword(s):

Estrogen Receptor ◽

Plasminogen Activator ◽

Hepg2 Cells ◽

Plasminogen Activator Inhibitor ◽

Estrogen Receptor Α ◽

Plasminogen Activator Inhibitor 1 ◽

17Β Estradiol ◽

Activator Inhibitor ◽

Pai 1

SummaryA low estrogen status in postmenopausal women is associated with elevated plasma levels of plasminogen activator inhibitor-1 (PAI-1). In this study, the ability of estrogen compounds to regulate PAI-1 expression was determined in a hepatocyte HepG2 cell line made to stably express estrogen receptor α (ERα). In both the wild type and ER expressing HepG2 cells, estrogen had no effect on basal PAI-1 expression. However, in the ER expressing cells the ability of IL-1β to increase PAI-1 mRNA and protein levels was attenuated by 17β-estradiol, tamoxifen and twelve estrogen components of Premarin. In contrast, the mixed agonist/antagonist raloxifene had weak agonist activity and like the pure antagonist ICI 182780, it dose dependently blocked the effect of 17β-estradiol on IL-1β stimulated PAI-1 levels. These results suggest that estrogen agonists may lower PAI-1 levels in vivo by inhibiting cytokine activated PAI-1 expression by an ER dependent mechanism.

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PARP7 and Mono-ADP-Ribosylation Negatively Regulate Estrogen Receptor α Signaling in Human Breast Cancer Cells

Cells ◽

10.3390/cells10030623 ◽

2021 ◽

Vol 10 (3) ◽

pp. 623

Author(s):

Marit Rasmussen ◽

Susanna Tan ◽

Venkata S. Somisetty ◽

David Hutin ◽

Ninni Elise Olafsen ◽

...

Keyword(s):

Breast Cancer ◽

Estrogen Receptor ◽

Protein Modification ◽

Target Genes ◽

Estrogen Receptor Α ◽

Transactivation Domain ◽

Adp Ribosylation ◽

Protein Levels ◽

17Β Estradiol ◽

Mcf 7

ADP-ribosylation is a post-translational protein modification catalyzed by a family of proteins known as poly-ADP-ribose polymerases. PARP7 (TIPARP; ARTD14) is a mono-ADP-ribosyltransferase involved in several cellular processes, including responses to hypoxia, innate immunity and regulation of nuclear receptors. Since previous studies suggested that PARP7 was regulated by 17β-estradiol, we investigated whether PARP7 regulates estrogen receptor α signaling. We confirmed the 17β-estradiol-dependent increases of PARP7 mRNA and protein levels in MCF-7 cells, and observed recruitment of estrogen receptor α to the promoter of PARP7. Overexpression of PARP7 decreased ligand-dependent estrogen receptor α signaling, while treatment of PARP7 knockout MCF-7 cells with 17β-estradiol resulted in increased expression of and recruitment to estrogen receptor α target genes, in addition to increased proliferation. Co-immunoprecipitation assays revealed that PARP7 mono-ADP-ribosylated estrogen receptor α, and mass spectrometry mapped the modified peptides to the receptor’s ligand-independent transactivation domain. Co-immunoprecipitation with truncated estrogen receptor α variants identified that the hinge region of the receptor is required for PARP7-dependent mono-ADP-ribosylation. These results imply that PARP7-mediated mono-ADP-ribosylation may play an important role in estrogen receptor positive breast cancer.

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Multiple forms of estrogen receptor-α in cerebral blood vessels: regulation by estrogen

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00165.2002 ◽

2003 ◽

Vol 284 (1) ◽

pp. E184-E192 ◽

Cited By ~ 74

Author(s):

Chris Stirone ◽

Sue P. Duckles ◽

Diana N. Krause

Keyword(s):

Estrogen Receptor ◽

Blood Vessels ◽

Estrogen Receptor Α ◽

26S Proteasome ◽

Target Tissue ◽

Female Rat ◽

Cerebral Vasculature ◽

Cerebral Blood Vessels ◽

Multiple Forms

The cerebral vasculature is an important target tissue for estrogen, as evidenced by significant effects of estrogen on vascular reactivity and protein levels of endothelial nitric oxide synthase and prostacyclin synthase. However, the presence, localization, and regulation of estrogen receptors in the cerebral vasculature have not been investigated. In this study, we identified the presence of estrogen receptor-α (ER-α) in female rat cerebral blood vessels and localized this receptor to both smooth muscle and endothelial cells by use of immunohistochemistry and confocal microscopy. With immunoblot analysis, multiple forms of ER-α were detected at 110, 93, 82, 50, and 45 kDa in addition to a relatively weak band corresponding to the 66-kDa putative unmodified receptor. The 82-kDa band was identified as Ser118-phosphorylated ER-α, whereas the 50-kDa band lacks the normal NH2 terminus, suggestive of an ER-α splice variant. Lower molecular mass bands persisted after in vivo inhibition of 26S proteasome activity with lactacystin, whereas the 110- and 93-kDa bands increased. All forms of ER-α in cerebral vessels were decreased after ovariectomy but significantly increased after chronic estrogen exposure in vivo.

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