scholarly journals MicroRNA levels in bone and blood change during bisphosphonate and teriparatide therapy in an animal model of postmenopausal osteoporosis

2019 ◽  
Author(s):  
Roland Kocijan ◽  
Moritz Weigl ◽  
Susanna Skalicky ◽  
Elisabeth Geiger ◽  
James Ferguson ◽  
...  
Keyword(s):  
Animal Model ◽  
Femoral Head ◽  
Bone Loss ◽  
Postmenopausal Osteoporosis ◽  
Bone Tissue ◽  
Peripheral Blood ◽  
List Type ◽  
Mrna Levels ◽  
Ovx Rats ◽  
Anabolic Treatment

ABSTRACTMicroRNAs control the activity of a variety of genes that are pivotal to bone metabolism. Therefore, the clinical utility of miRNAs as biomarkers and drug targets for bone diseases certainly merits further investigation. This study describes the use of an animal model of postmenopausal osteoporosis to generate a comprehensive dataset on miRNA regulation in bone tissue and peripheral blood during bone loss and specifically anti-resorptive and osteo-anabolic treatment.Forty-two Sprague-Dawley rats were randomized to SHAM surgery (n=10) or ovariectomy (OVX, n=32). Eight weeks after surgery, OVX animals were further randomized to anti-resorptive treatment with zoledronate (n=11), osteo-anabolic treatment with teriparatide (n=11), or vehicle treatment (n=10). After 12 weeks of treatment, bone and serum samples were used for microRNA analysis using next-generation sequencing (NGS), mRNA levels using RT-qPCR, and bone microarchitecture analysis using nanoCT.Ovariectomy resulted in loss of trabecular bone, which was fully rescued using osteo-anabolic treatment, and partially rescued using anti-resorptive treatment. NGS revealed that both, anti-resorptive and anabolic treatment had a significant impact on miRNA levels in bone tissue and serum: out of 426 detected miRNAs, 46 miRNAs were regulated by teriparatide treatment an d 10 by zoledronate treatment (p-adj. < 0.1). Interestingly, teriparatide and zoledronate treatment were able to revert miRNA changes in tissue and serum of untreated OVX animals, such as the up-regulation of miR-203a-3p, a known osteo-inhibitory miRNA. We confirmed previously established mechanisms of miR-203a by analyzing its direct target Dlx5 in femoral head.Our data reveal a significant effect of ovariectomy-induced bone loss, as well as the two major types of anti-osteoporotic treatment on miRNA transcription in femoral head tissue. These changes are associated with altered activity of target genes relevant to bone formation, such as Dlx5. The observed effects of bone loss and treatment response on miRNA levels in bone are also reflected in the peripheral blood, suggesting the possibility of minimally-invasive monitoring of bone-derived miRNAs using liquid biopsies.HighlightsmicroRNA expression in bone tissue is altered by osteo-anabolic and anti-resorptive therapy in OVX rats.microRNA changes in untreated OVX rats are reverted by anti-osteoporotic therapy.miR-203a is up-regulated during bone loss and down-regulated following therapy.Bone tissue and serum levels of miR-203a are highly correlated.

scholarly journals PERK controls bone homeostasis through the regulation of osteoclast differentiation and function

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Jiachao Guo ◽  
Ranyue Ren ◽  
Kai Sun ◽  
Xudong Yao ◽  
Jiamin Lin ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Bone Loss ◽  
Er Stress ◽  
Bone Tissue ◽  
Protein Modification ◽  
Osteoclast Differentiation ◽  
Marker Genes ◽  
Mrna Levels ◽  
Bone Homeostasis ◽  
Related Proteins

Abstract Osteoclasts are multinucleated giant cells with the ability to degrade bone tissue, and are closely related to abnormal bone metabolic diseases. Endoplasmic reticulum (ER) is an organelle responsible for protein modification, quality control, and transportation. The accumulation of unfolded or misfolded proteins in ER cavity induces ER stress. Double-stranded RNA-dependent protein kinase-like ER kinase (PERK) is an ER stress-sensing protein, which is ubiquitous in eukaryotic cells. Systemic PERK knockout mice show severe bone loss, suggesting that PERK is of great significance for maintaining the normal growth and development of bone tissue, but the role of PERK in osteoclastogenesis is still unclear. In this study, we found that PERK was significantly activated during RANKL-induced osteoclast differentiation; knockdown of PERK by siRNA and inhibition of PERK by GSK2606414, respectively, had significant negative regulatory effects on the formation and bone resorption of osteoclasts. PERK inhibitor GSK2606414 down-regulated the mRNA levels and protein expression of osteoclast differentiation marker genes, and inhibited RANKL-induced activation of Mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) pathways. Treatment with PERK inhibitor GSK2606414 in ovariectomized mouse model significantly suppressed bone loss and osteoclast formation. Thapsigargin activated ER stress to enhance autophagy, while GSK2606414 had a significant inhibitory effect on autophagy flux and autophagosome formation. Antioxidant N-acetylcysteine (NAC) could inhibit the expression of PERK phosphorylation, osteoclast-related proteins and autophagy-related proteins, but the use of PERK activator CCT020312 can reverse inhibition effect of NAC. Our findings demonstrate a key role for PERK in osteoclast differentiation and suggest its therapeutic potential.

Chronic treatment with angiotensin AT1 receptor antagonists reduced serum but not bone TGF-β1 levels in ovariectomized rats

2009 ◽  
Vol 87 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Yong-Qi Li ◽  
Hui Ji ◽  
Yang Shen ◽  
Li-Ju Ding ◽  
Pei Zhuang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Postmenopausal Osteoporosis ◽  
Chronic Treatment ◽  
Transforming Growth Factor ◽  
Ovariectomized Rats ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mineral Density ◽  
Receptor Antagonists ◽  
Ovx Rats ◽  
At1 Receptor Antagonists

Approximately 50% of hypertensive patients are postmenopausal women; therefore, any antihypertensive therapy must not adversely affect bone loss in this population. Recently, however, concern has been raised that use of angiotensin AT1 receptor antagonists may increase the tendency to develop postmenopausal osteoporosis by decreasing transforming growth factor-β1 (TGF-β1), which has been implicated in bone mass maintenance. In the present study, we selected telmisartan and valsartan as representatives of angiotensin AT1 receptor antagonists and used ovariectomized (OVX) rats as a model of human postmenopausal osteoporosis. After 3 months treatment with telmisartan (5 mg/kg daily) or valsartan (10 mg/kg daily), OVX rats showed no signs of adverse effects on bone mineral density of the lumbar vertebrae (L1–L5) or the total femur, nor did treatment affect serum levels of osteocalcin and osteoclast-derived tartrate-resistant acid phosphatase (TRACP-5b). Bone TGF-β1 content remained unchanged, although treatment with telmisartan and valsartan significantly reduced serum TGF-β1 levels (p < 0.05). In conclusion, chronic treatment with angiotensin AT1 receptor antagonists reduced serum but not bone TGF-β1 levels and did not accelerate ovariectomy-induced bone loss in rats.

scholarly journals Icariin Treatment Enhanced the Skeletal Response to Exercise in Estrogen-Deficient Rats

2019 ◽  
Vol 16 (19) ◽  
pp. 3779
Author(s):  
Zhao ◽  
Bu ◽  
Chen
Keyword(s):  
Bone Loss ◽  
Mechanical Strain ◽  
Elevated Serum ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Ovx Rats ◽  
Phosphorylated Akt ◽  
Related Transcription Factor ◽  
The Difference

Estrogen deficiency frequently leads to a fall in estrogen receptor- (ER) numbers and then reduces the skeletal response to mechanical strain. It, however, is still unclear whether phytoestrogen administration will enhance the effects of exercise on the estrogen-deficient bone loss. This study aimed to determine the effect of Icariin treatment on the response of osteogenic formation to exercise in ovariectomized (OVX) rats. Thirty-two 3-month old female Sprague–Dawley rats were randomly allocated into four groups: (1) Sham-operated (SO); (2) OVX; (3) OVX plus exercise (EX); and (4) OVX plus exercise and Icariin (EI). After 8-week interventions, the rats were killed and samples were collected for bone morphometry, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses. EI interventions showed a greater improvement for the OVX-induced bone loss and the elevated serum tartrate-resistant acid phosphatase (TRAP) and alkaline phosphatase (ALP) compared with EX only. Both EX and EI interventions bettered the OVX-related reduction of BV/TV and trabecular number and thickness, and decreased the enlargement of trabecular bone separation (Tb. Sp); the improvement for BV/TV and Tb. Sp was greater in EI group. Furthermore, EX and EI treatment significantly increased the number of ALP+ cells and mineralized nodule areas compared with OVX group; the change was higher in EI group. Additionally, in comparison to OVX rats, the protein and mRNA expression of -catenin, phosphorylated-Akt (p-Akt) or Akt, ER, and Runt-related transcription factor 2 (Runx2) in osteoblasts were elevated in EX and EI intervention rats, with greater change observed in EI group. The upregulated -catenin and Akt mRNA levels in EX and EI groups was depressed by ICI182780 treatment, and the difference in -catenin and Akt mRNA levels between EX and EI groups was no longer significant. Conclusively, the combination of Icariin and exercise significantly prevent OVX-induced bone loss and increase osteoblast differentiation and the ability of mineralization compared with exercise alone; the changes might be regulated partly by ER/Akt/-catenin pathway.

scholarly journals Green Tomato Extract Prevents Bone Loss in Ovariectomized Rats, a Model of Osteoporosis

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3210
Author(s):  
Farida S. Nirmala ◽  
Hyunjung Lee ◽  
Ji-Sun Kim ◽  
Taeyoul Ha ◽  
Chang Hwa Jung ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Postmenopausal Osteoporosis ◽  
Ovariectomized Rats ◽  
Bone Homeostasis ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Tomato Extract ◽  
Ovx Rats

Although drug therapies are available for postmenopausal osteoporosis, these drugs are not free of side effects and long-term adherence to them are low. A safe and effective nutritional approach to counter postmenopausal osteoporosis is an important research goal. We fed ovariectomized (OVX) Sprague–Dawley rats a diet supplemented with 1% or 2% green tomato extract (GTE). After 12 weeks, micro-computed tomography scans revealed that GTE supplementation effectively prevented distal femur bone loss. This prevention was due to improved bone formation and suppressed bone resorption as observed by the regulation of osteoblast and osteoclast activities. GTE supplementation also improved bone formation through Bmp2-Smad 1/5/8-Runx2 signaling, while bone resorption was regulated by the receptor activator of nuclear factor kappa-B (RANKL)/osteoprogeterin (OPG) pathway. These results suggest that GTE supplementation prevents severe postmenopausal bone loss by maintaining the regulation of bone homeostasis in OVX rats. GTE as a diet supplement might be a potential novel alternative for the prevention of postmenopausal osteoporosis.

scholarly journals Effects of age on immune function in broiler chickens

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bochen Song ◽  
Dazhi Tang ◽  
Shaojia Yan ◽  
Hao Fan ◽  
Guang Li ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Function ◽  
Cellular Immunity ◽  
Mucosal Immunity ◽  
Peripheral Blood ◽  
Broiler Chickens ◽  
Mrna Levels ◽  
Cell Ratio ◽  
Cell Functions ◽  
Ifn Γ

Abstract Background There are many diseases in poultry, many of which are caused by poor immune function. It is not clear how cytokines and various immune cell functions change with age in modern broilers. The purpose of this study was to explore the patterns of development of the immunity of the broiler chickens in cage. Results The results showed that there were 3 development patterns of immunity in the broiler chickens. The first pattern was Down-Up. Cytokines and some immune indicators first decreased and then increased, and the lowest levels of immunity basically occurred from d 6 to 13. The second pattern was Up-Down, and from d 30 to 34, the highest levels of non-specific cellular immunity components, such as the peripheral blood mononuclear macrophage ratio, specific cellular immunity components, such as the peripheral blood helper T (Th) cell ratio and T cell and B cell proliferation activity, and mucosal immunity components, such as the ileal CD4, TGF-β1 and IgA mRNA levels, were observed. The third pattern was Up-Up, and the levels of the non-specific cellular immunity components, such as the serum nitric oxide (NO), C3 and C4 levels, the specific cellular immunity components, such as the spleen index, peripheral blood IL-2, IFN-γ/IL-4, cytotoxic T (Tc) cell ratio, and splenic NF-κB mRNA levels, the humoral immunity components, such as the serum IgG level, the mucosal immunity components, such as the ileal MHC-II, CD3d, TCRβ subunit, TCRζ subunit, IFN-γ, pIgR mRNA and ileal mucosa sIgA levels, were continuing to increase from d 1 to 34. Conclusions It could be concluded that the immune system and its function have not developed well in the broiler chickens d 6 to 13 and that the immune system does not mature until d 30 to 34 in the broiler chickens in cages. It is necessary to enhance the immune function of the broiler chickens through nutritional measures from d 1 to 30.

330 Investigating the clinical safety, efficacy, and immune modulation of combined XL888 and pembrolizumab in metastatic gastrointestinal malignancies

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A356-A356
Author(s):  
Cameron Herting ◽  
Yuchen Zhang ◽  
Deon Doxie ◽  
Matthew Farren ◽  
Michael Ware ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cell ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Peripheral Blood ◽  
Immune Modulation ◽  
Heat Shock Protein 90 ◽  
Pancreatic Stellate Cells ◽  
List Type ◽  
Biopsy Specimens

BackgroundBoth pancreatic ductal adenocarcinoma (PDAC) and metastatic colorectal cancer (mCRC) have yet to widely benefit from T cell-targeted immunotherapy and have universally poor prognoses. Thus, enhancing the activity of immunotherapy is a high priority. Our laboratory recently reported that heat shock protein-90 (Hsp90) inhibition enhances the efficacy of PD-1 blockade in preclinical models of PDAC.1 Mechanistically, Hsp90 inhibitors can limit activation of cancer associated fibroblasts (CAF) and promote infiltration of T cells when combined with PD-1 blockade. Based on these data, we are conducting a Phase Ib/II clinical trial to evaluate the combination of XL888 (Hsp90 inhibitor) and pembrolizumab in patients with metastatic pancreatic and colorectal cancers. We hypothesize that this combination will be safe and elicit pronounced microenvironmental changes, leading to enhanced efficacy.MethodsDuring the phase II portion, PDAC or mCRC patients (n=16 each) were randomized to receive a three week lead in with either pembrolizumab or pembrolizumab and XL888. Paired biopsies were obtained at baseline and at week two on treatment. A comprehensive panel of immunologic correlatives studies is being conducted to examine treatment-induced alterations in the tumor microenvironment and peripheral blood.ResultsAs of August 23rd, 2020, paired liver biopsy specimens from sites of metastasis have been successfully obtained from a total of 15 patients (n=7 PDAC and n=8 mCRC). These specimens underwent single cell mass cytometry (CyTOF) analysis to assess immunophenotypic markers of T and myeloid cells. Using this approach, we have generated a comprehensive view of the immune landscape at baseline and following treatment. These data will be validated by immunohistochemical analysis of FFPE biopsy specimens obtained in parallel at the time of CyTOF analysis. In addition to these correlative studies, using immortalized and primary CAF from PDAC patients, we have shown XL888 dampens production of IL-6 and other cytokines in vitro. The impact of XL888 on systemic cytokines and chemokines (n=48 total) in the peripheral blood from patients enrolled in the clinical trial is therefore also being assessed.ConclusionsOur correlative analysis of paired biopsies and peripheral blood from a novel clinical trial of XL888 and pembrolizumab will allow for further mechanistic insight into treatment-induced immune modulation. These data will also serve to validate whether alterations of CAF phenotype, cytokine and chemokine release, and T cell infiltration observed preclinically are mirrored in patients.Trial RegistrationThis clinical trial is underway and registered with the ID NCT03095781.Ethics ApprovalThe study was approved by Emory University’s Ethics Board, approval IRB00087397.ReferenceZhang Y, Ware MB, Zaidi M, Ruggieri AN, Olson B, Komar H, Farren MR, Nagaraju GP, Zhang C, Chen Z, Sarmiento J, Ahmed R, Maithel SK, El-Rayes BF, Lesinski GB. Heat shock protein-90 inhibition alters activation of pancreatic stellate cells and enhances the efficacy of PD-1 blockade in pancreatic cancer. Molecular Cancer Therapeutics 2020.

scholarly journals Bone Marrow Homeostasis Is Impaired via JAK/STAT and Glucocorticoid Signaling in Cancer Cachexia Model

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1059
Author(s):  
Jinyeong Yu ◽  
Sanghyuk Choi ◽  
Aran Park ◽  
Jungbeom Do ◽  
Donghyun Nam ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Animal Model ◽  
Bone Loss ◽  
Cancer Cachexia ◽  
Mononuclear Cells ◽  
Bone Homeostasis ◽  
Bone Marrow Mscs ◽  
Hematopoietic Stem ◽  
Glucocorticoid Signaling

Cancer cachexia is a multifactorial systemic inflammation disease caused by complex interactions between the tumor and host tissues via soluble factors. However, whether cancer cachexia affects the bone marrow, in particular the hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs), remains unclear. Here, we investigated the bone marrow and bone in a cancer cachexia animal model generated by transplanting Lewis lung carcinoma cells. The number of bone marrow mononuclear cells (BM-MNCs) started to significantly decrease in the cancer cachectic animal model prior to the discernable loss of muscle and fat. This decrease in BM-MNCs was associated with myeloid skewing in the circulation and the expansion of hematopoietic progenitors in the bone marrow. Bone loss occurred in the cancer cachexia animal model and accompanied the decrease in the bone marrow MSCs that play important roles in both supporting HSCs and maintaining bone homeostasis. Glucocorticoid signaling mediated the decrease in bone marrow MSCs in the cancer cachectic environment. The cancer cachexia environment also skewed the differentiation of the bone marrow MSCs toward adipogenic fate via JAK/STAT as well as glucocorticoid signaling. Our results suggest that the bone loss induced in cancer cachexia is associated with the depletion and the impaired differentiation capacity of the bone marrow MSCs.

542 Expansion of cytotoxic NK Cells from PBMCs using individualized cytokine combination

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A578-A578
Author(s):  
Andreia Maia ◽  
Joana Lerias ◽  
Markus Maeurer ◽  
Mireia Castillo-Martin
Keyword(s):  
Flow Cytometry ◽  
Nk Cells ◽  
Natural Killer ◽  
Peripheral Blood ◽  
Blood Donors ◽  
Nk Cell ◽  
Tumour Cells ◽  
List Type ◽  
Mhc I ◽  
Cytokine Combination

BackgroundAdoptive immunotherapy relies on the use of T-cells to target tumour cells, through Major Histocompatibility Complex (MHC) Class I recognition(1). However, many tumours display alterations in the MHC-I pathway, a well-described immune evasion mechanism(2). Natural Killer (NK) cells recognize transformed cells independently from the presence of MHC-I and may be a reliable therapeutic option for patients with altered tumour MHC-I expression. The source of NK cells may be autologous or allogeneic and NK cells are also clinically relevant recipients of transgenic receptors (TCRs or antibodies) targeting tumour cells. NK cells have been categorized according to their CD56 and CD16 surface expression into different subpopulations: cytotoxic (CD56+CD16+) and regulatory (CD56brightCD16-)(3). Expanding cytotoxic NK cells is challenging, since the frequency of NK cells is low in peripheral blood(4) and there is also – at this point – not an optimal expansion protocol available.The goal of this project is to determine the best cytokine combination that facilitates expansion of cytotoxic NK cells that either target tumor cells directly or serve as recipients for transgenic receptors.MethodsPeripheral Blood Mononuclear Cells (PBMCs) were extracted using Ficoll methodology from blood donors and cultured in T25 flasks with Cell Genix Medium supplemented with 10% human serum and antibiotics. NK cells were expanded supplemented with feeder cells (ratio 1:1) and different cytokine combinations (1000 U/mL of IL-2, 10 U/ml of IL-12, 180 U/mL of IL-15 and/or 1 U/mL of IL-21) during 20 days. The immunophenotype of expanded NK cells was analyzed at days 0, 5, 10, 15 and 20 by flow cytometry. The cytotoxicity of NK cells was measured by a CD107a Assay or by a Total Cytotoxicity and Apoptosis Assay at days 10 and 20. Thirteen different cytokine combinations were tested.Results4/13 cytokine combinations produced a statistically significant increase of the absolute number of NK cells with a higher percentage of cytotoxic NK cells (figure 1). However, induction of cytotoxicity was not associated with a strong NK cell expansion. The regulatory NK cells subset (CD56brightCD16-) showed the highest percentage of CD107a-expressing cells, more than the CD56+CD16+, the most cytotoxic subpopulation of NK cells.Abstract 542 Figure 1Representative percentage of NK cells in total lymphocytes (A), CD56+CD16+ subpopulation in total NK cells (B), and CD56brightCD16- subpopulation amongst total NK cells (C) at different time points (5, 10, 15 and 20 days) expanded from PBMCs* p-value < 0.05ConclusionsThis work shows that we are able to grow and efficiently expand NK cells from PBMCs with different cytokine combinations leading to clinically relevant NK cell numbers as well as cytotoxic functions. This enables to produce NK cell products for therapy and as recipients for transgenic tumor antigen-specific receptors.AcknowledgementsThe authors would like to thank the Champalimaud Foundation Biobank, the Vivarium Facility and the Flow Cytometry Platform of the Champalimaud Centre for the Unknown.Ethics ApprovalThis study was approved by the Champalimaud Foundation Ethics Committee and by the Ethics Research Committee of NOVA Medical School of NOVA University of Lisbon.ConsentWritten informed consent was obtained from the blood donors to use their samples for research purposes.ReferencesRosenberg SA, Restifo NP, Yang JC, Morgan RA, Mark E. Adoptive cell transfer: a clinical path to effective cancer immunotherapy. Nat Rev Cancer 2008;8(4):299–308.Aptsiauri N, Ruiz-Cabello F, Garrido F. The transition from HLA-I positive to HLA-I negative primary tumors: the road to escape from T-cell responses. Curr Opin Immunol 2018;51:123–32.Di Vito C, Mikulak J, Mavilio D. On the way to become a natural killer cell. Front Immunol. 2019;10(August):1–15.Zotto G Del, Antonini F, Pesce S, Moretta F, Moretta L. Comprehensive phenotyping of human PB NK Cells by Flow Cytometry. 2020;1–9.

Physiological plasma levels of androgens reduce bone loss in the ovariectomized rat

1998 ◽  
Vol 274 (2) ◽  
pp. E328-E335 ◽  
Author(s):  
C. K. Lea ◽  
A. M. Flanagan
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Protective Effect ◽  
Cancellous Bone ◽  
Plasma Levels ◽  
Slow Release ◽  
Bone Volume ◽  
Ovariectomized Rat ◽  
Ovx Rats ◽  
Reduce Bone Loss

The effect of androstenedione (ADIONE) slow-release pellets on cancellous bone volume (BV/TV) at the tibial metaphysis was investigated in ovariectomized (OVX) rats at various times from 21 to 180 days. Plasma levels of ADIONE and testosterone (T) in OVX rats were significantly reduced at 21 days and were restored close to levels in the sham rats with the 1.5-mg ADIONE pellet. OVX animals with and without ADIONE pellets resulted in close to a 50% reduction in BV/TV by day 21. By day 180, OVX rats had only ∼5% BV/TV, whereas that in ADIONE-treated OVX rats was significantly greater at ∼12%. The reduced BV/TV was associated with increased bone resorption and formation. In a separate 90-day experiment, we found that the antiandrogen, Casodex, abrogated the ADIONE-induced skeletal-protective effect in OVX rats, whereas the antiaromatase, Arimidex, had no effect. This provides evidence that ADIONE protects against the development of osteopenia in the estrogen-deficient rat and mediates its effect through androgens and not estrogens.

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