| 1. |
- Nilsson, Maria E., et al.
(författare)
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Measurement of a comprehensive sex steroid profile in rodent serum by high-sensitive gas chromatography-tandem mass spectrometry.
- 2015
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 156:7, s. 2492-502
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Tidskriftsartikel (refereegranskat)abstract
- Accurate measurement of sex steroid concentrations in rodent serum is essential to evaluate mouse and rat models for sex steroid-related disorders. The aim of the present study was to develop a sensitive and specific gas chromatography-tandem mass spectrometry (GC-MS/MS) method to assess a comprehensive sex steroid profile in rodent serum. A major effort was invested in reaching an exceptionally high sensitivity for measuring serum estradiol concentrations. We established a GC-MS/MS assay with a lower limit of detection for estradiol, estrone, testosterone, dihydrotestosterone, progesterone, androstenedione and dehydroepiandrosterone of 0.3, 0.5, 4, 1.6, 8, 4 and 50 pg/ml, respectively, while the corresponding values for the lower limit of quantification were 0.5, 0.5, 8, 2.5, 74, 12 and 400 pg/ml, respectively. Calibration curves were linear, intra- and inter-assay CVs were low and accuracy was excellent for all analytes. The established assay was used to accurately measure a comprehensive sex steroid profile in female rats and mice according to estrus cycle phase. In addition, we characterized the impact of age, sex, gonadectomy, and estradiol treatment on serum concentrations of these sex hormones in mice. In conclusion, we have established a highly sensitive and specific GC-MS/MS method to assess a comprehensive sex steroid profile in rodent serum in a single run. This GC-MS/MS assay has, to the best of our knowledge, the best detectability reported for estradiol. Our method therefore represents an ideal tool to characterize sex steroid metabolism in a variety of sex steroid-related rodent models and in human samples with low estradiol levels.
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| 2. |
- Börjesson, Anna E, et al.
(författare)
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SERMs have substance-specific effects on bone, and these effects are mediated via ER alpha AF-1 in female mice
- 2016
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Ingår i: American Journal of Physiology-Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 310:11
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Tidskriftsartikel (refereegranskat)abstract
- The bone-sparing effect of estrogens is mediated primarily via estrogen receptor (ER)alpha, which stimulates gene transcription through activation function (AF)-1 and AF-2. The role of ER alpha AF-1 for the estradiol (E-2) effects is tissue specific. The selective ER modulators (SERMs) raloxifene (Ral), lasofoxifene (Las), and bazedoxifene (Bza) can be used to treat postmenopausal osteoporosis. They all reduce the risk for vertebral fractures, whereas Las and partly Bza, but not Ral, reduce the risk for nonvertebral fractures. Here, we have compared the tissue specificity of Ral, Las, and Bza and evaluated the role of ER alpha AF-1 for the effects of these SERMs, with an emphasis on bone parameters. We treated ovariectomized (OVX) wild-type (WT) mice and OVX mice lacking ER alpha AF-1 (ER alpha AF-1(0)) with E-2, Ral, Las, or Bza. All three SERMs increased trabecular bone mass in the axial skeleton. In the appendicular skeleton, only Las increased the trabecular bone volume/tissue volume and trabecular number, whereas both Ral and Las increased the cortical bone thickness and strength. However, Ral also increased cortical porosity. The three SERMs had only a minor effect on uterine weight. Notably, all evaluated effects of these SERMs were absent in ovx ER alpha AF-1(0) mice. In conclusion, all SERMs had similar effects on axial bone mass. However, the SERMs had slightly different effects on the appendicular skeleton since only Las increased the trabecular bone mass and only Ral increased the cortical porosity. Importantly, all SERM effects require a functional ER alpha AF-1 in female mice. These results could lead to development of more specific treatments for osteoporosis.
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| 3. |
- Börjesson, Anna E, et al.
(författare)
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The role of activation functions 1 and 2 of estrogen receptor-alpha for the effects of estradiol and selective estrogen receptor modulators in male mice
- 2013
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 28:5, s. 1117-1126
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Tidskriftsartikel (refereegranskat)abstract
- Estradiol (E2) is important for male skeletal health and the effect of E2 is mediated via estrogen receptor (ER)-. This was demonstrated by the findings that men with an inactivating mutation in aromatase or a nonfunctional ER had osteopenia and continued longitudinal growth after sexual maturation. The aim of the present study was to evaluate the role of different domains of ER for the effects of E2 and selective estrogen receptor modulators (SERMs) on bone mass in males. Three mouse models lacking either ERAF-1 (ERAF-10), ERAF-2 (ERAF-20), or the total ER (ER/) were orchidectomized (orx) and treated with E2 or placebo. E2 treatment increased the trabecular and cortical bone mass and bone strength, whereas it reduced the thymus weight and bone marrow cellularity in orx wild type (WT) mice. These parameters did not respond to E2 treatment in orx ER/ or ERAF-20 mirx ERAF-10 mice were tissue-dependent, with a clear response in cortical bone parameters and bone marrow cellularity, but no response in trabecular bone. To determine the role of ERAF-1 for the effects of SERMs, we treated orx WT and ERAF-10 mice with raloxifene (Ral), lasofoxifene (Las), bazedoxifene (Bza), or vehicle. These SERMs increased total body areal bone mineral density (BMD) and trabecular volumetric BMD to a similar extent in orx WT mice. Furthermore, only Las increased cortical thickness significantly and only Bza increased bone strength significantly. However, all SERMs showed a tendency toward increased cortical bone parameters. Importantly, all SERM effects were absent in the orx ERAF-10 mice. In conclusion, ERAF-2 is required for the estrogenic effects on all evaluated parameters, whereas the role of ERAF-1 is tissue-specific. All evaluated effects of Ral, Las and Bza are dependent on a functional ERAF-1. Our findings might contribute to the development of bone-specific SERMs in males. (c) 2013 American Society for Bone and Mineral Research.
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| 4. |
- Colldén, Hannah, et al.
(författare)
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Dehydroepiandrosterone Supplementation Results in Varying Tissue-specific Levels of Dihydrotestosterone in Male Mice
- 2022
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 163:12
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Tidskriftsartikel (refereegranskat)abstract
- Dehydroepiandrosterone (DHEA), an adrenal androgen precursor, can be metabolized in target tissues into active sex steroids. It has been proposed that DHEA supplementation might result in restoration of physiological local sex steroid levels, but knowledge on the effect of DHEA treatment on local sex steroid levels in multiple tissues is lacking. To determine the effects of DHEA on tissue-specific levels of sex steroids, we treated orchiectomized (ORX) male mice with DHEA for 3 weeks and compared them with vehicle-treated ORX mice and gonadal intact mice. Intra-tissue levels of sex steroids were analyzed in reproductive organs (seminal vesicles, prostate, m. levator ani), major body compartments (white adipose tissue, skeletal muscle, and brain), adrenals, liver, and serum using a sensitive and validated gas chromatography-mass spectrometry method. DHEA treatment restored levels of both testosterone (T) and dihydrotestosterone (DHT) to approximately physiological levels in male reproductive organs. In contrast, this treatment did not increase DHT levels in skeletal muscle or brain. In the liver, DHEA treatment substantially increased levels of T (at least 4-fold) and DHT (+536%, P < 0.01) compared with vehicle-treated ORX mice. In conclusion, we provide a comprehensive map of the effect of DHEA treatment on intra-tissue sex steroid levels in ORX mice with a restoration of physiological levels of androgens in male reproductive organs while DHT levels were not restored in the skeletal muscle or brain. This, and the unexpected supraphysiological androgen levels in the liver, may be a cause for concern considering the uncontrolled use of DHEA.
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| 5. |
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| 6. |
- Gustafsson, Karin L., 1987, et al.
(författare)
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A tissue-specific role of membrane-initiated ERα signaling for the effects of SERMs
- 2022
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Ingår i: Journal of Endocrinology. - 0022-0795. ; 253:2, s. 75-84
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Tidskriftsartikel (refereegranskat)abstract
- Selective estrogen receptor modulators (SERMs) act as estrogen receptor (ER) agonists or antagonists in a tissue-specific manner. ERs exert effects via nuclear actions but can also utilize membrane-initiated signaling pathways. To dete rmine if membrane-initiated ERα (mERα) signaling affects SERM action in a tissue-specific manner, C451 A mice, lacking mERα signaling due to a mutation at palmitoylation site C451, were treated with Lasofoxifene (Las), Bazedoxifene (Bza), or estradi ol (E2), and various tissues were evaluated. Las and Bza treatment increased uterine weight to a similar extent in C451A and control mice, demonstrating mERα-independent uterine SERM effects, while the E2 effect on the uterus was predominantly mER α-dependent. Las and Bza treatment increased both trabecular and cortical bone mass in controls to a similar degree as E2, while both SERM and E2 treatment effects were abse nt in C451A mice. This demonstrates that SERM effects, similar to E2 effects, in th e skeleton are mERα- dependent. Both Las and E2 treatment decreased thymus weight in controls, while neither treatment affected the thymus in C451A mice, demonstrati ng mERα-dependent SERM and E2 effects in this tissue. Interestingly, both SERM and E2 treatments decreased the total body fat percent in C451A mice, demonstrating the ability of these treatments to affect fat tissue in the absence of functional mER α signaling. In conclusion, mERα signaling can modulate SERM responses in a tissue-specific manne r. This novel knowledge increases the understanding of the mechanisms behind SERM effects and may thereby facilitate the development of new improved SERMs.
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| 7. |
- Gustafsson, Karin L., 1987, et al.
(författare)
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The role of membrane ER alpha signaling in bone and other major estrogen responsive tissues
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen receptor a (ER alpha) signaling leads to cellular responses in several tissues and in addition to nuclear ER alpha-mediated effects, membrane ER alpha (mER alpha) signaling may be of importance. To elucidate the significance, in vivo, of mER alpha signaling in multiple estrogen-responsive tissues, we have used female mice lacking the ability to localize ER alpha to the membrane due to a point mutation in the palmitoylation site (C451A), so called Nuclear-Only-ER (NOER) mice. Interestingly, the role of mER alpha signaling for the estrogen response was highly tissue-dependent, with trabecular bone in the axial skeleton being strongly dependent (>80% reduction in estrogen response in NOER mice), cortical and trabecular bone in long bones, as well as uterus and thymus being partly dependent (40-70% reduction in estrogen response in NOER mice) and effects on liver weight and total body fat mass being essentially independent of mER alpha (<35% reduction in estrogen response in NOER mice). In conclusion, mER alpha signaling is important for the estrogenic response in female mice in a tissue-dependent manner. Increased knowledge regarding membrane initiated ER alpha actions may provide means to develop new selective estrogen receptor modulators with improved profiles.
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| 8. |
- Jiang, Yiwen, et al.
(författare)
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Membrane estrogen receptor alpha signaling modulates the sensitivity to estradiol treatment in a dose- and tissue- dependent manner
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Estradiol (E2) affects both reproductive and non-reproductive tissues, and the sensitivity to different doses of E2 varies between tissues. Membrane estrogen receptor alpha (mER alpha)-initiated signaling plays a tissue-specific role in mediating E2 effects, however, it is unclear if mER alpha signaling modulates E2 sensitivity. To determine this, we treated ovariectomized C451A females, lacking mER alpha signaling, and wildtype (WT) littermates with physiological (0.05 mu g/mouse/day (low); 0.6 mu g/mouse/day (medium)) or supraphysiological (6 mu g/mouse/day (high)) doses of E2 (17 beta-estradiol-3-benzoate) for three weeks. Low-dose treatment increased uterus weight in WT, but not C451A mice, while non-reproductive tissues (gonadal fat, thymus, trabecular and cortical bone) were unaffected in both genotypes. Medium-dose treatment increased uterus weight and bone mass and decreased thymus and gonadal fat weights in WT mice. Uterus weight was also increased in C451A mice, but the response was significantly attenuated (- 85%) compared to WT mice, and no effects were triggered in non-reproductive tissues. High-dose treatment effects in thymus and trabecular bone were significantly blunted (- 34% and - 64%, respectively) in C451A compared to WT mice, and responses in cortical bone and gonadal fat were similar between genotypes. Interestingly, the high dose effect in uterus was enhanced (+ 26%) in C451A compared to WT mice. In conclusion, loss of mER alpha signaling reduces the sensitivity to physiological E2 treatment in both non-reproductive tissues and uterus. Furthermore, the E2 effect after high-dose treatment in uterus is enhanced in the absence of mER alpha, suggesting a protective effect of mER alpha signaling in this tissue against supraphysiological E2 levels.
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| 9. |
- Lagerquist, Marie K, et al.
(författare)
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Reduction of Mature B Cells and Immunoglobulins Results in Increased Trabecular Bone
- 2022
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Ingår i: Jbmr Plus. - : Wiley. - 2473-4039. ; 6:9
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation has a significant effect on bone remodeling and can result in bone loss via increased stimulation of osteoclasts. Activated immunoglobulins, especially autoantibodies, can increase osteoclastogenesis and are associated with pathological bone loss. Whether immunoglobulins and mature B lymphocytes are important for general bone architecture has not been completely determined. Here we demonstrate, using a transgenic mouse model, that reduction of mature B cells and immunoglobulins leads to increased trabecular bone mass compared to wild-type (WT) littermate controls. This bone effect is associated with a decrease in the number of osteoclasts and reduced bone resorption, despite decreased expression of osteoprotegerin. We also demonstrate that the reduction of mature B cells and immunoglobulins do not prevent bone loss caused by estrogen deficiency or arthritis compared to WT littermate controls. In conclusion, the reduction of mature B cells and immunoglobulins results in disturbed regulation of trabecular bone turnover in healthy conditions but is dispensable for pathological bone loss. (c) 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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| 10. |
- Movérare-Skrtic, Sofia, et al.
(författare)
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The bone-sparing effects of estrogen and WNT16 are independent of each other
- 2015
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 112:48, s. 14972-14977
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Tidskriftsartikel (refereegranskat)abstract
- Wingless-type MMTV integration site family (WNT)16 is a key regulator of bone mass with high expression in cortical bone, and Wnt16-/- mice have reduced cortical bone mass. As Wnt16 expression is enhanced by estradiol treatment, we hypothesized that the bone-sparing effect of estrogen in females isWNT16-dependent. This hypothesis was tested in mechanistic studies using two genetically modified mouse models with either constantly high osteoblastic Wnt16 expression or no Wnt16 expression. We developed a mouse model with osteoblast-specific Wnt16 overexpression (Obl-Wnt16). These mice had several-fold elevated Wnt16 expression in both trabecular and cortical bone compared with wild type (WT) mice. Obl- Wnt16 mice displayed increased total body bone mineral density (BMD), surprisingly caused mainly by a substantial increase in trabecular bone mass, resulting in improved bone strength of vertebrae L3. Ovariectomy (ovx) reduced the total body BMD and the trabecular bone mass to the same degree in Obl-Wnt16 mice and WT mice, suggesting that the bone-sparing effect of estrogen is WNT16-independent. However, these bone parameters were similar in ovx Obl- Wnt16 mice and sham operated WT mice. The role of WNT16 for the bone-sparing effect of estrogen was also evaluated in Wnt16-/- mice. Treatment with estradiol increased the trabecular and cortical bone mass to a similar extent in both Wnt16-/- and WT mice. In conclusion, the bone-sparing effects of estrogen and WNT16 are independent of each other. Furthermore, loss of endogenous WNT16 results specifically in cortical bone loss, whereas overexpression of WNT16 surprisingly increases mainly trabecular bone mass. WNT16- targeted therapies might be useful for treatment of postmenopausal trabecular bone loss.
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