Tissue selective effects of bazedoxifene on the musculoskeletal system in female mice

The actions of selective estrogen receptor modulators are tissue dependent. The primary objective of the current study was to determine the tissue selective effects of bazedoxifene (BZA) on the musculoskeletal system of ovariectomized (OVX) female mice, focusing on strengths of muscle-bone pairs in the lower hindlimb. Treatment with BZA after ovariectomy (OVX+BZA) did not prevent body or fat mass gains (p<0.05). In vivo plantarflexor muscle isometric torque was not affected by treatment with BZA (p=0.522). Soleus muscle peak isometric, concentric and eccentric tetanic force production were greater in OVX+BZA mice compared to OVX+E2 mice (p≤0.048) with no effect on maximal isometric specific force (p=0.228). Tibia from OVX+BZA mice had greater cortical cross-sectional area and moment of inertia than OVX mice treated with placebo (p<0.001), but there was no impact of BZA treatment on cortical bone mineral density, cortical thickness, tibial bone ultimate load or stiffness (p≥0.086). Overall, these results indicate that BZA may be an estrogen receptor agonist in skeletal muscle, as it has previously been shown in bone, providing minor benefits to the musculoskeletal system.

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The effects of ovariectomy on bone mineral density, geometrical, and biomechanical characteristics in the rabbit femur

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-08-09-0085 ◽

2010 ◽

Vol 23 (01) ◽

pp. 31-36 ◽

Cited By ~ 7

Author(s):

M. E. Kara ◽

F. Sevil

Keyword(s):

Bone Mineral Density ◽

Bone Mineral ◽

Animal Studies ◽

Biomechanical Properties ◽

Mineral Density ◽

Cross Sectional ◽

Tomographic Images ◽

Three Point Bending ◽

Rabbit Femur

SummaryThe aim of the study was to evaluate the bone mineral density, as well as the biomechanic and morphometric changes in the femur of ovariectomised rabbits.Twenty-four six-month-old New Zealand rabbits were randomly divided into an ovariectomy (n = 12) and a sham (n = 12) group. Six rabbits in each group were euthanatized at eight and 16 weeks after surgery, and the femora were resected. The morphometric data were obtained from tomographic images. Periosteal and endosteal diameters and cortical thickness were measured. Total cross-sectional, cortical and medullary areas were also measured. The bone mineral content, the bone area and the bone mineral density were measured from the proximal, distal and mid-shaft of the femur as well as the total femur by dual energy X-ray absorptiometry. Employing the three-point bending method, the ultimate force, stiffness and work-to-failure were measured. The mechanical data were normalised to obtain intrinsic biomechanical properties such as ultimate stress, elastic modulus, and toughness, all of which are independent of size and shape.The results indicated that the femur was both larger and weaker 16 weeks after surgery in the ovariectomised group. Results also suggest that the rabbit might be a useful animal model for investigation of diseases related to oestrogen loss such as human postmenopausal osteoporosis. However, additional studies with advanced techniques at several time points via in vivo animal studies, and precision and predictability analyses should be designed to standardise the rabbit as a model for osteoporosis.

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Estrogen receptor specificity in the regulation of the skeleton in female mice

Journal of Endocrinology ◽

10.1677/joe.0.1710229 ◽

2001 ◽

Vol 171 (2) ◽

pp. 229-236 ◽

Cited By ~ 140

Author(s):

MK Lindberg ◽

SL Alatalo ◽

JM Halleen ◽

S Mohan ◽

JA Gustafsson ◽

...

Keyword(s):

Estrogen Receptor ◽

Estrogen Receptor Alpha ◽

Bone Growth ◽

Fat Content ◽

Mineral Density ◽

Trabecular Bone Mineral Density ◽

Longitudinal Bone Growth ◽

Female Mice ◽

Opposing Effects ◽

Er Alpha

There are two known estrogen receptors, estrogen receptor-alpha (ER alpha) and estrogen receptor-beta (ER beta), which may mediate the actions of estrogen. The aim of the present study was to compare fat content, skeletal growth and adult bone metabolism in female mice lacking ER alpha (ERKO), ER beta (BERKO) or both ERs (DERKO). We demonstrate that endogenous estrogens decrease the fat content in female mice via ER alpha and not ER beta. Interestingly, the longitudinal bone growth was decreased in ERKO, increased in BERKO, but was intermediate in DERKO females, demonstrating that ER alpha and ER beta exert opposing effects in the regulation of longitudinal bone growth. The effects on longitudinal bone growth were correlated with similar effects on serum levels of IGF-I. A complex regulation of the trabecular bone mineral density (BMD), probably caused by a disturbed feedback regulation of estrogen and testosterone, was observed in female ER-inactivated mice. Nevertheless, a partial functional redundancy for ER alpha and ER beta in the maintenance of the trabecular BMD was observed in the female mice at 60 days of age. Thus, ER alpha and ER beta may have separate effects (regulation of fat), opposing effects (longitudinal bone growth) or partial redundant effects (trabecular BMD at 60 days of age), depending on which parameter is studied.

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Drug-Herb Interaction Between Selective Estrogen Receptor Modulators and Estrogenic Herbal Medicine Er-Xian Decoction in Bone in Vivo and in Vitro

10.21203/rs.3.rs-101206/v1 ◽

2020 ◽

Author(s):

Ka-Ying Wong ◽

Liping Zhou ◽

Wenxuan Yu ◽

Christina Chui Wa Poon ◽

Man-Sau Wong

Keyword(s):

Estrogen Receptor ◽

Selective Estrogen Receptor Modulators ◽

Serum Estradiol ◽

Mineral Density ◽

Alp Activity ◽

Estrogen Receptor Modulators ◽

Combined Use ◽

Receptor Modulators

Abstract Background: Er-Xian decoction (EXD), a traditional Chinese Medicine for managing menopausal syndrome and osteoporosis in China, could exert osteoprotective action via activation of estrogen receptor (ERs) and regulation of serum estradiol without causing severe side effects. However, no fundamental studies have explored its potential interaction in the combined use of prescription drugs, Selective Estrogen Receptor Modulators (SERMs), regarding the osteogenic and uterotrophic effects. The present study evaluated the estrogenic effects of EXD and its potential interactions with tamoxifen and raloxifene in bone and uterus using a mature ovariectomized (OVX) Sprague-Dawley (SD) rat model and human osteoblastic MG-63 cells. Methods: Six-month-old female SD rats were randomly assigned to Sham-operated group or seven OVX groups: vehicle, 17ß-estradiol (E2, 1.0 mg/kg.day), Tamoxifen (Tamo, 1.0 mg/kg.day), Raloxifene (Ralo, 3.0 mg/kg.day), EXD (EXD, 1.6 g/kg.day), EXD+Tamoxifen (EXD+Tamo) and EXD+Raloxifene (EXD+Ralo). The effect of EXD on bodyweight, bone mineral density (BMD), bone microarchitecture, biochemical analysis of serum and urine, and uterus were evaluated. In addition, Alkaline phosphatase assay and activation of estrogen-responsive element mediated by EXD and in its combination with SERMs were investigated in MG-63 cells. Results: In vivo, EXD could interact with SERMs to modulate the serum estradiol, follicle-stimulating hormone, osteocalcin level as well as BMD and bone properties in OVX rats. Moreover, EXD could relieve the uterotrophic effect of SERMs. In vitro, EXD crude extract and EXD-treated serum could promote ALP activity. In particular, EXD-treated serum could interact with SERMs on regulating ALP activity in MG-63 cells. Conclusion: Our study demonstrated that EXD in vivo and EXD-treated serum in vitro did not weaken the osteogenic effect of SERMs. Interestingly, EXD seems to ameliorate the uterotrophic effects of SERMs. Therefore, the combined use of EXD and SERMs may be considered safe and effective in managing postmenopausal osteoporosis.

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The Non-Erythropoietic EPO Analogue (Cibinetide) Preserves Bone Mass in Mice

Blood ◽

10.1182/blood-2021-147204 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 850-850

Author(s):

Zamzam Awida ◽

Almog Bachar ◽

Hussam Saed ◽

Anton Gorodov ◽

Nathalie Ben-Califa ◽

...

Keyword(s):

Bone Loss ◽

Cancer Biology ◽

Molecular Mechanisms ◽

Conflicts Of Interest ◽

Erythroid Progenitors ◽

Mineral Density ◽

Female Mice ◽

Tissue Protection

Abstract Background and aims: Erythropoietin (EPO) is a pleiotropic cytokine, which besides its classical role in driving erythropoiesis, displays tissue protective and immunomodulatory activities. EPO also induces bone loss. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. Cibinetide (CIB), a non-erythropoietic analogue of EPO, specifically binds to the heteromeric receptor and confers tissue protection. Our published findings that EPO stimulates osteoclast precursors and entrains a decrease in bone density, raise questions regarding the underlying molecular mechanisms. Here, we evaluated the role of the heteromeric complex in bone metabolism using CIB alone and in combination with EPO in vivo and in vitro. Results: CIB injections to 12-week-old female mice (120 µg/kg thrice weekly for 4 weeks) resulted in a significant increase in tissue mineral density in cortical bone by 5.8% (1416.4±39.27 vs 1338.74±16.56 mgHA/cm 3) and in trabecular bone by 5.2% (1056.52±30.94 vs 1004.13±16.91 mg HA/cm 3) (n=10 in each group, p< 0.05 versus saline-injected controls), as measured by microCT (Figure 1A). To evaluate the capacity of CIB to attenuate EPO mediated bone loss, we administered CIB (300 µg/kg) for 5 consecutive days, to 13-week-old female mice that also received 2 injections of 120U EPO on days 1 and 4. Flow cytometry analysis revealed a 1.8-fold reduction in the number of osteoclast progenitors, defined as Lin -CD11b −CD115 +Ly6C hi, in the EPO + CIB injected mice, compared to the mice injected with EPO alone (n=7 in each group, p< 0.05). Hemoglobin levels and TER119 + bone marrow (BM) erythroid progenitors were similar in both groups. In vitro, EPO administration to BM-derived macrophages (BMDM) enhanced osteoclastogenesis, whereas CIB had an opposite, dose-dependent effect. Combining CIB with EPO inhibited osteoclastogenesis in BMDM, suggesting that CIB overrides the pro-osteoclastogenic effect of EPO (Figure 1B). Conclusions: Our findings highlight the increasing complexity of EPOR signaling in bone and pave the way for clinical translation through potential combination therapy of EPO and CIB in anemic and in cancer patients. Adjunctive administration of CIB may prevent or attenuate bone loss while preserving the erythropoietic actions of EPO. This study was supported by a grant from the Dotan Hemato-oncology Fund, the Cancer Biology Research Center, Tel Aviv University to DN and YG. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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The Non-Erythropoietic EPO Analogue Cibinetide Inhibits Osteoclastogenesis In Vitro and Increases Bone Mineral Density in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms23010055 ◽

2021 ◽

Vol 23 (1) ◽

pp. 55

Author(s):

Zamzam Awida ◽

Almog Bachar ◽

Hussam Saed ◽

Anton Gorodov ◽

Nathalie Ben-Califa ◽

...

Keyword(s):

Bone Mineral Density ◽

Bone Loss ◽

Bone Mineral ◽

Molecular Mechanisms ◽

Mineral Density ◽

Female Mice ◽

Epo Receptor

The two erythropoietin (EPO) receptor forms mediate different cellular responses to erythropoietin. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. In the skeletal system, EPO stimulates osteoclast precursors and induces bone loss. However, the underlying molecular mechanisms are still elusive. Here, we evaluated the role of the heteromeric complex in bone metabolism in vivo and in vitro by using Cibinetide (CIB), a non-erythropoietic EPO analogue that exclusively binds the heteromeric receptor. CIB is administered either alone or in combination with EPO. One month of CIB treatment significantly increased the cortical (~5.8%) and trabecular (~5.2%) bone mineral density in C57BL/6J WT female mice. Similarly, administration of CIB for five consecutive days to female mice that concurrently received EPO on days one and four, reduced the number of osteoclast progenitors, defined by flow cytometry as Lin−CD11b−Ly6Chi CD115+, by 42.8% compared to treatment with EPO alone. In addition, CIB alone or in combination with EPO inhibited osteoclastogenesis in vitro. Our findings introduce CIB either as a stand-alone treatment, or in combination with EPO, as an appealing candidate for the treatment of the bone loss that accompanies EPO treatment.

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The bi-modal effects of estradiol on gonadotropin synthesis and secretion in female mice are dependent on estrogen receptor-α

Journal of Endocrinology ◽

10.1677/joe.1.06965 ◽

2006 ◽

Vol 191 (1) ◽

pp. 309-317 ◽

Cited By ~ 28

Author(s):

Jonathan Lindzey ◽

Friederike L Jayes ◽

Mariana M Yates ◽

John F Couse ◽

Kenneth S Korach

Keyword(s):

Estrogen Receptor ◽

Negative Feedback ◽

Primary Cultures ◽

Estrogen Receptor Α ◽

High Plasma ◽

Pituitary Cells ◽

Gonadotropin Secretion ◽

Female Mice ◽

Positive Effects

Depending on the estrous/menstrual cycle stage in females, ovarian-derived estradiol (E2) exerts either a negative or a positive effect on the hypothalamic–pituitary axis to regulate the synthesis and secretion of pituitary gonadotropins, LH, and FSH. To study the role of estrogen receptor-α (ERα) mediating these effects, we assessed the relevant parameters in adult wild-type (WT) and ERα-null (αERKO) female mice in vivo and in primary pituitary cell cultures. The αERKO mice exhibited significantly higher plasma and pituitary LH levels relative to WT females despite possessing markedly high levels of circulating E2. In contrast, hypothalamic GnRH content and circulating FSH levels were comparable between genotypes. Ovariectomy led to increased plasma LH in WT females but no further increase in αERKO females, while plasma FSH levels increased in both genotypes. E2 treatment suppressed the high plasma LH and pituitary Lhb mRNA expression in ovariectomized WT females but had no effect in αERKO. In contrast, E2 treatments only partially suppressed plasma FSH in ovariectomized WT females, but this too was lacking in αERKO females. Therefore, negative feedback on FSH is partially E2/ERα mediated but more dependent on ovarian-derived inhibin, which was increased threefold above normal in αERKO females. Together, these data indicate that E2-mediated negative feedback is dependent on functional ERα and acts to primarily regulate LH synthesis and secretion. Studies in primary cultures of pituitary cells from WT females revealed that E2 did not suppress basal or GnRH-induced LH secretion but instead enhanced the latter response, indicating that the positive influence of E2 on gonadotropin secretion may occur at the level of the pituitary. Once again this effect was lacking in αERKO gonadotropes in culture. These data indicate that the aspects of negative and positive effects of E2 on gonadotropin secretion are ERα dependent and occur at the level of the hypothalamus and pituitary respectively.

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In vivo tibial stiffness is maintained by whole bone morphology and cross-sectional geometry in growing female mice

Journal of Biomechanics ◽

10.1016/j.jbiomech.2010.06.019 ◽

2010 ◽

Vol 43 (14) ◽

pp. 2689-2694 ◽

Cited By ~ 36

Author(s):

Russell P. Main ◽

Maureen E. Lynch ◽

Marjolein C.H. van der Meulen

Keyword(s):

Bone Morphology ◽

Cross Sectional ◽

Female Mice

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Estrogen Inhibits Cardiac Hypertrophy: Role of Estrogen Receptor-β to Inhibit Calcineurin

Endocrinology ◽

10.1210/en.2008-0133 ◽

2008 ◽

Vol 149 (7) ◽

pp. 3361-3369 ◽

Cited By ~ 114

Author(s):

Ali Pedram ◽

Mahnaz Razandi ◽

Dennis Lubahn ◽

Jinghua Liu ◽

Mani Vannan ◽

...

Keyword(s):

Estrogen Receptor ◽

Cardiac Hypertrophy ◽

Protein Expression ◽

Cardiac Fibrosis ◽

Interacting Protein ◽

Female Mice ◽

Cellular Effects ◽

Gene And Protein Expression ◽

Β Receptor

Estrogen has been reported to prevent development of cardiac hypertrophy in female rodent models and in humans. However, the mechanisms of sex steroid action are incompletely understood. We determined the cellular effects by which 17β-estradiol (E2) inhibits angiotensin II (AngII)-induced cardiac hypertrophy in vivo. Two weeks of angiotensin infusion in female mice resulted in marked hypertrophy of the left ventricle, exacerbated by the loss of ovarian steroid hormones from oophorectomy. Hypertrophy was 51% reversed by the administration of E2 (insertion of 0.1 mg/21-d-release tablets). The effects of E2 were mainly mediated by the estrogen receptor (ER) β-isoform, because E2 had little effect in ERβ-null mice but comparably inhibited AngII-induced hypertrophy in wild-type or ERα-null mice. AngII induced a switch of myosin heavy chain production from α to β, but this was inhibited by E2 via ERβ. AngII-induced ERK activation was also inhibited by E2 through the β-receptor. E2 stimulated brain natriuretic peptide protein expression and substantially prevented ventricular interstitial cardiac fibrosis (collagen deposition) as induced by AngII. Importantly, E2 inhibited calcineurin activity that was stimulated by AngII, related to E2 stimulating the modulatory calcineurin-interacting protein (MCIP) 1 gene and protein expression. E2 acting mainly through ERβ mitigates the important signaling by AngII that produces cardiac hypertrophy and fibrosis in female mice.

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Specific force of the vastus lateralis in adults with achondroplasia

Journal of Applied Physiology ◽

10.1152/japplphysiol.00638.2017 ◽

2018 ◽

Vol 124 (3) ◽

pp. 696-703 ◽

Cited By ~ 7

Author(s):

David T. Sims ◽

Gladys L. Onambélé-Pearson ◽

Adrian Burden ◽

Carl Payton ◽

Christopher I. Morse

Keyword(s):

Vastus Lateralis ◽

Force Production ◽

Limb Length ◽

Muscle Size ◽

Knee Extensors ◽

Specific Force ◽

Moment Arm ◽

Cross Sectional ◽

Volume Activation

Achondroplasia is a clinical condition defined by shorter stature and disproportionate limb length. Force production in able-bodied individuals (controls) is proportional to muscle size, but given the disproportionate nature of achondroplasia, normalizing to anatomical cross-sectional area (ACSA) is inappropriate. The aim of this study was to assess specific force of the vastus lateralis (VL) in 10 adults with achondroplasia (22 ± 3 yr) and 18 sex-matched controls (22 ± 2 yr). Isometric torque (iMVCτ) of the dominant knee extensors (KE) and in vivo measures of VL muscle architecture, volume, activation, and patella tendon moment arm were used to calculate VL physiological CSA (PCSA), fascicle force, and specific force in both groups. Achondroplasic muscle volume was 53% smaller than controls (284 ± 36 vs. 604 ± 102 cm3, P < 0.001). KE iMVCτ was 63% lower in achondroplasia compared with controls (95 ± 24 vs. 256 ± 47 N⋅m, P < 0.001). Activation and moment arm length were similar between groups ( P > 0.05), but coactivation of bicep femoris of achondroplasic subjects was 70% more than controls (43 ± 20 vs. 13 ± 5%, P < 0.001). Achondroplasic subjects had 58% less PCSA (43 ± 10 vs. 74.7 ± 14 cm2, P < 0.001), 29% lower fascicle force (702 ± 235 vs. 1704 ± 303 N, P < 0.001), and 29% lower specific force than control subjects (17 ± 6 vs. 24 ± 6 N⋅cm−2, P = 0.012). The smaller VL specific force in achondroplasia may be attributed to infiltration of fat and connective tissue, rather than to any difference in myofilament function. NEW & NOTEWORTHY The novel observation of this study was the measurement of normalized force production in a group of individuals with disproportionate limb length-to-torso ratios.

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Evaluation of estrogenic potential by herbal formula, HPC 03 for in vitro and in vivo

Reproduction ◽

10.1530/rep-17-0530 ◽

2018 ◽

Vol 155 (2) ◽

pp. 103-113 ◽

Cited By ~ 5

Author(s):

Bo Yoon Chang ◽

Dae Sung Kim ◽

Hye Soo Kim ◽

Sung Yeon Kim

Keyword(s):

Estrogen Receptor ◽

Ovariectomized Rats ◽

Herbal Formula ◽

Mineral Density ◽

Bone Mineral Density Loss ◽

Ovx Rats ◽

Estrogenic Potential ◽

Mcf 7

HPC 03 is herbal formula that consists of extracts from Angelica gigas, Cnidium officinale Makino and Cinnamomum cassia Presl. The present study evaluated the estrogenic potential of HPC 03 by using in vitro and in vivo models. The regulatory mechanisms of HPC 03 in estrogen-dependent MCF-7 cells were assessed. HPC 03 induced the proliferation of estrogen receptor-positive MCF-7 cells, and the proliferation was blocked by the addition of the estrogen antagonist tamoxifen. The estrogen receptorα/β luciferase activities were significantly increased by HPC 03 treatment, which also increased the mRNA expression of the estrogen-responsive genes Psen2, Pgr and Ctsd. Also, we evaluated the ameliorative effects of HPC 03 on menopausal symptoms in ovariectomized rats. HPC 03 treatment in OVX rats significantly affected the uterine weight, increased the expression of estrogen-responsive genes Pgr and Psen2 in uterus, increased bone mineral density loss in the femur and inhibited body weight increase. Serum E2, collagen type 1 and osteocalcin were significantly increased, while serum LH, FSH and ALP were decreased compared with OVX rats. HPC 03 may be a promising candidate for the treatment of menopause, but further research is necessary to determine whether the observed effects also occur in humans.

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