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Niwczyk O, Grymowicz M, Szczęsnowicz A, Hajbos M, Kostrzak A, Budzik M, Maciejewska-Jeske M, Bala G, Smolarczyk R, Męczekalski B. Bones and Hormones: Interaction between Hormones of the Hypothalamus, Pituitary, Adipose Tissue and Bone. Int J Mol Sci 2023; 24:ijms24076840. [PMID: 37047811 PMCID: PMC10094866 DOI: 10.3390/ijms24076840] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023] Open
Abstract
The bony skeleton, as a structural foundation for the human body, is essential in providing mechanical function and movement. The human skeleton is a highly specialized and dynamic organ that undergoes continuous remodeling as it adapts to the demands of its environment. Advances in research over the last decade have shone light on the various hormones that influence this process, modulating the metabolism and structural integrity of bone. More recently, novel and non-traditional functions of hypothalamic, pituitary, and adipose hormones and their effects on bone homeostasis have been proposed. This review highlights recent work on physiological bone remodeling and discusses our knowledge, as it currently stands, on the systemic interplay of factors regulating this interaction. In this review, we provide a summary of the literature on the relationship between bone physiology and hormones including kisspeptin, neuropeptide Y, follicle-stimulating hormone (FSH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), growth hormone (GH), leptin, and adiponectin. The discovery and understanding of this new functionality unveils an entirely new layer of physiologic circuitry.
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Affiliation(s)
- Olga Niwczyk
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences, 60-535 Poznan, Poland
| | - Monika Grymowicz
- Department of Gynecological Endocrinology, Medical University of Warsaw, 00-315 Warsaw, Poland
| | - Aleksandra Szczęsnowicz
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences, 60-535 Poznan, Poland
| | - Marta Hajbos
- Department of Gynecological Endocrinology, Medical University of Warsaw, 00-315 Warsaw, Poland
| | - Anna Kostrzak
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences, 60-535 Poznan, Poland
| | - Michał Budzik
- Department of Gynecological Endocrinology, Medical University of Warsaw, 00-315 Warsaw, Poland
- Department of Cancer Prevention, Medical University of Warsaw, 02-091 Warsaw, Poland
| | - Marzena Maciejewska-Jeske
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences, 60-535 Poznan, Poland
| | - Gregory Bala
- UCD School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Roman Smolarczyk
- Department of Gynecological Endocrinology, Medical University of Warsaw, 00-315 Warsaw, Poland
| | - Błażej Męczekalski
- Department of Gynecological Endocrinology, Poznan University of Medical Sciences, 60-535 Poznan, Poland
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Intra-pituitary follicle-stimulating hormone signaling regulates hepatic lipid metabolism in mice. Nat Commun 2023; 14:1098. [PMID: 36841874 PMCID: PMC9968338 DOI: 10.1038/s41467-023-36681-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/09/2023] [Indexed: 02/27/2023] Open
Abstract
Inter-organ communication is a major hallmark of health and is often orchestrated by hormones released by the anterior pituitary gland. Pituitary gonadotropes secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to regulate gonadal function and control fertility. Whether FSH and LH also act on organs other than the gonads is debated. Here, we find that gonadotrope depletion in adult female mice triggers profound hypogonadism, obesity, glucose intolerance, fatty liver, and bone loss. The absence of sex steroids precipitates these phenotypes, with the notable exception of fatty liver, which results from ovary-independent actions of FSH. We uncover paracrine FSH action on pituitary corticotropes as a mechanism to restrain the production of corticosterone and prevent hepatic steatosis. Our data demonstrate that functional communication of two distinct hormone-secreting cell populations in the pituitary regulates hepatic lipid metabolism.
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Lung cancer aggressiveness in an intermittent hypoxia murine model of postmenopausal sleep apnea. ACTA ACUST UNITED AC 2021; 27:706-713. [PMID: 32108736 DOI: 10.1097/gme.0000000000001526] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Intermittent hypoxia (IH)-a hallmark of obstructive sleep apnea (OSA)-enhances lung cancer progression in mice via altered host immune responses that are also age and sex-dependent. However, the interactions of menopause with IH on tumor malignant properties remain unexplored. Here, we aimed to investigate lung cancer outcomes in the context of ovariectomy (OVX)-induced menopause in a murine model of OSA. METHODS Thirty-four female mice (C57BL/6, 12-week-old) were subjected to bilateral OVX or to Sham intervention. Six months after surgery, mice were pre-exposed to either IH or room air (RA) for 2 weeks. Then, 10 lung carcinoma (LLC1) cells were injected subcutaneously in the left flank, with IH or RA exposures continued for 4 weeks. Tumor weight, tumor invasion, and spontaneous lung metastases were assessed. Tumor-associated macrophages (TAMs) were isolated and subjected to flow cytometry polarity evaluation along with assessment of TAMs modulation of LLC1 proliferation in vitro. To determine the effect of IH and OVX on each experimental variable, a two-way analysis of variance was performed. RESULTS IH and OVX promoted a similar increase in tumor growth (∼2-fold; P = 0.05 and ∼1.74-fold; P < 0.05, respectively), and OVX-IH further increased it. Regarding lung metastasis, the concurrence of OVX in mice exposed to IH enhanced the number of metastases (23.7 ± 8.0) in comparison to those without OVX (7.9 ± 2.8; P < 0.05). The pro-tumoral phenotype of TAMS, assessed as M2/M1 ratio, was increased in OVX (0.06 ± 0.01; P < 0.01) and IH (0.06 ± 0.01; P < 0.01) compared with sham/RA conditions (0.14 ± 0.03). The co-culture of TAMS with naive LLC1 cells enhanced their proliferation only under IH. CONCLUSION In female mice, both the IH that is characteristically present in OSA and OVX as a menopause model emerge as independent contributors that promote lung cancer aggressiveness and seemingly operate through alterations in the host immune response.
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Liu Y, Zhang M, Kong D, Wang Y, Li J, Liu W, Fu Y, Xu J. High follicle-stimulating hormone levels accelerate cartilage damage of knee osteoarthritis in postmenopausal women through the PI3K/AKT/NF-κB pathway. FEBS Open Bio 2020; 10:2235-2245. [PMID: 32911565 PMCID: PMC7530390 DOI: 10.1002/2211-5463.12975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/02/2020] [Accepted: 09/04/2020] [Indexed: 11/24/2022] Open
Abstract
Osteoarthritis is the main cause of pain and disability in the elderly, with the most commonly affected joint being the knee. The prevalence of knee osteoarthritis (KOA) is significantly increased in postmenopausal women, although the mechanisms underlying KOA remain unclear. The present study aimed to investigate the association between follicle‐stimulating hormone (FSH) and postmenopausal women with KOA aged between 50 and > 70 years, as well as explore its underlying molecular mechanisms. Here, we report that the 50–60 years age group had the highest level of serum FSH. Compared to the low FSH group (< 40 mIU·mL−1) in the same age group, the high FSH group (> 40 mIU·mL−1) showed more severe cartilage damage. Furthermore, phosphorylated (p)‐phosphoinositide 3‐kinase (PI3K)/PI3K, p‐AKT/AKT and p‐nuclear factor kappa B (NF‐κB)/NF‐κB levels were significantly higher in the high FSH group compared to the low FSH group. Immunofluorescence experiments showed that FSH stimulation promoted the translocation of NF‐κB p65 into the nucleus, and decreased type II collagen and aggrecan in ATDC5 cells. Moreover, we used western blotting in ATDC5 cells to demonstrate that FSH decreased type II collagen and increased p‐PI3K/PI3K, p‐AKT/AKT, p‐NF‐κB/NF‐κB and p‐IKB/IKB in a concentration‐dependent manner. Our results suggest that increased FSH levels are associated with KOA for postmenopausal women aged 50–60 years and that high FSH levels might damage the cartilage tissues through the PI3K/AKT/NF‐κB pathway.
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Affiliation(s)
- Yaping Liu
- Department of Endocrinology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.,Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, China.,Department of Endocrinology, Jining No. 1 People's Hospital, Jining, China
| | - Mengqi Zhang
- Department of Endocrinology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.,Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, China
| | - Dehuan Kong
- Department of Endocrinology, Taian City Central Hospital, Taian, China
| | - Yan Wang
- Department of Endocrinology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.,Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, China
| | - Jian Li
- Department of Bone and Joint Surgery, Jining No. 1 People's Hospital, Jining, China
| | - Wenjuan Liu
- Department of Magnetic Resonance Imaging, Jining No. 1 People's Hospital, Jining, China
| | - Yilin Fu
- Department of Endocrinology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.,Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, China
| | - Jin Xu
- Department of Endocrinology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, China.,Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, China.,Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
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Raval AP, Martinez CC, Mejias NH, de Rivero Vaccari JP. Sexual dimorphism in inflammasome-containing extracellular vesicles and the regulation of innate immunity in the brain of reproductive senescent females. Neurochem Int 2018; 127:29-37. [PMID: 30500463 DOI: 10.1016/j.neuint.2018.11.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022]
Abstract
A woman's risk for stroke increases exponentially following the onset of menopause; however, the underlying mechanisms responsible for the increased risk remain unknown. The depletion of endogenous estrogen at menopause is known to activate the inflammatory response. Therefore, in this study we have used reproductively senescent (RS) rats to test the hypotheses that (1) inflammasome activation is significantly higher in the brain of RS females (RSF) as compared to their younger counterparts and age-matched senescent male rats, and that (2) RS triggers an innate immune response mediated in part by inflammasome-containing extracellular vesicles (EV) that originate in the female reproductive organs and then spreads to the brain. We tested these hypotheses using male and female Sprague-Dawley rats (Young: 6-7 months and RS: 9-13 months). Hippocampus, gonads and serum were collected. Additionally, cerebrospinal fluid (CSF) of pre- and post-menopausal women (ages 23 to 37 and 52 to 68) was purchased and extracellular vesicles (EV) were isolated from serum and CSF. The Inflammasome proteins caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and IL-1β were then resolved by immunoblotting. We found that inflammasome protein expression increased significantly in the analyzed tissues in RSF as compared to young females (YF), such difference was not present in age-matched male rat brains. Interestingly, we found that Nik-related kinase (NRK), which is present in female reproductive organs was present in the CSF and serum-derived EV, suggesting that the source of the EV seen in the brain during RS/menopause originate, in part, in the female reproductive organs. Thus, this study shows for the first time an involvement of the inflammasome originating in the female reproductive system as a contributor to inflammation in the brain that makes the peri-menopausal women's brain more susceptible to neurodegenerative diseases such as stroke.
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Affiliation(s)
- Ami P Raval
- Cerebral Vascular Disease Research Laboratories, Department of Neurology, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.
| | - Camila C Martinez
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Nancy H Mejias
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Juan Pablo de Rivero Vaccari
- Department of Neurological Surgery and The Miami Project to Cure Paralysis, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, USA.
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Idelevich A, Baron R. Brain to bone: What is the contribution of the brain to skeletal homeostasis? Bone 2018; 115:31-42. [PMID: 29777919 PMCID: PMC6110971 DOI: 10.1016/j.bone.2018.05.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/15/2018] [Accepted: 05/15/2018] [Indexed: 12/13/2022]
Abstract
The brain, which governs most, if not all, physiological functions in the body, from the complexities of cognition, learning and memory, to the regulation of basal body temperature, heart rate and breathing, has long been known to affect skeletal health. In particular, the hypothalamus - located at the base of the brain in close proximity to the medial eminence, where the blood-brain-barrier is not as tight as in other regions of the brain but rather "leaky", due to fenestrated capillaries - is exposed to a variety of circulating body cues, such as nutrients (glucose, fatty acids, amino acids), and hormones (insulin, glucagon, leptin, adiponectin) [1-3].Information collected from the body via these peripheral cues is integrated by hypothalamic sensing neurons and glial cells [4-7], which express receptors for these nutrients and hormones, transforming these cues into physiological outputs. Interestingly, many of the same molecules, including leptin, adiponectin and insulin, regulate both energy and skeletal homeostasis. Moreover, they act on a common set of hypothalamic nuclei and their residing neurons, activating endocrine and neuronal systems, which ultimately fine-tune the body to new physiological states. This review will focus exclusively on the brain-to-bone pathway, highlighting the most important anatomical sites within the brain, which are known to affect bone, but not covering the input pathways and molecules informing the brain of the energy and bone metabolic status, covered elsewhere [8-10]. The discussion in each section will present side by side the metabolic and bone-related functions of hypothalamic nuclei, in an attempt to answer some of the long-standing questions of whether energy is affected by bone remodeling and homeostasis and vice versa.
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Affiliation(s)
- Anna Idelevich
- Department of Medicine, Harvard Medical School and Endocrine Unit MGH, Division of Bone and Mineral Metabolism, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Roland Baron
- Department of Medicine, Harvard Medical School and Endocrine Unit MGH, Division of Bone and Mineral Metabolism, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
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FSH and TSH in the regulation of bone mass: the pituitary/immune/bone axis. Clin Dev Immunol 2013; 2013:382698. [PMID: 23818914 PMCID: PMC3683445 DOI: 10.1155/2013/382698] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 11/21/2022]
Abstract
Recent evidences have highlighted that the pituitary hormones have profound effects on bone, so that the pituitary-bone axis is now becoming an important issue in the skeletal biology. Here, we discuss the topical evidence about the dysfunction of the pituitary-bone axis that leads to osteoporotic bone loss. We will explore the context of FSH and TSH hormones arguing their direct or indirect role in bone loss. In addition, we will focus on the knowledge that both FSH and TSH have influence on proinflammatory and proosteoclastogenic cytokine expression, such as TNFα and IL-1, underlining the correlation of pituitary-bone axis to the immune system.
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Seitz S, Keller J, Schilling AF, Jeschke A, Marshall RP, Stride BD, Wintermantel T, Beil FT, Amling M, Schütz G, Tuckermann J, Schinke T. Pharmacological estrogen administration causes a FSH-independent osteo-anabolic effect requiring ER alpha in osteoblasts. PLoS One 2012; 7:e50301. [PMID: 23209701 PMCID: PMC3507728 DOI: 10.1371/journal.pone.0050301] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 10/18/2012] [Indexed: 11/18/2022] Open
Abstract
Postmenopausal osteoporosis is characterized by declining estrogen levels, and estrogen replacement therapy has been proven beneficial for preventing bone loss in affected women. While the physiological functions of estrogen in bone, primarily the inhibition of bone resorption, have been studied extensively, the effects of pharmacological estrogen administration are still poorly characterized. Since elevated levels of follicle-stimulating hormone (FSH) have been suggested to be involved in postmenopausal bone loss, we investigated whether the skeletal response to pharmacological estrogen administration is mediated in a FSH-dependent manner. Therefore, we treated wildtype and FSHβ-deficicent (Fshb−/−) mice with estrogen for 4 weeks and subsequently analyzed their skeletal phenotype. Here we observed that estrogen treatment resulted in a significant increase of trabecular and cortical bone mass in both, wildtype and Fshb−/− mice. Unexpectedly, this FSH-independent pharmacological effect of estrogen was not caused by influencing bone resorption, but primarily by increasing bone formation. To understand the cellular and molecular nature of this osteo-anabolic effect we next administered estrogen to mouse models carrying cell specific mutant alleles of the estrogen receptor alpha (ERα). Here we found that the response to pharmacological estrogen administration was not affected by ERα inactivation in osteoclasts, while it was blunted in mice lacking the ERα in osteoblasts or in mice carrying a mutant ERα incapable of DNA binding. Taken together, our findings reveal a previously unknown osteo-anabolic effect of pharmacological estrogen administration, which is independent of FSH and requires DNA-binding of ERα in osteoblasts.
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Affiliation(s)
- Sebastian Seitz
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Johannes Keller
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Arndt F. Schilling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Plastic and Hand Surgery, Technische Universität München, Munich, Germany
| | - Anke Jeschke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robert P. Marshall
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Brenda D. Stride
- Division Molecular Biology of the Cell I, German Cancer Research Center, Heidelberg, Germany
| | - Tim Wintermantel
- Division Molecular Biology of the Cell I, German Cancer Research Center, Heidelberg, Germany
| | - Frank T. Beil
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Günther Schütz
- Division Molecular Biology of the Cell I, German Cancer Research Center, Heidelberg, Germany
| | - Jan Tuckermann
- Leibniz Institute for Age Research-Fritz Lipmann Institute, Jena, Germany
- * E-mail: (JT); (TS)
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail: (JT); (TS)
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Yoldemir T, Erenus M, Durmusoglu F. The impact of serum FSH and estradiol on postmenopausal osteoporosis related to time since menopause. Gynecol Endocrinol 2012; 28:884-8. [PMID: 22731753 DOI: 10.3109/09513590.2012.683066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIM To determine the impact on osteopenia/osteoporosis of serum follicle-stimulating hormone (FSH), estradiol levels and time since menopause in a group of Turkish postmenopausal women. METHODS Four hundred and thirty-three healthy postmenopausal women seen at the Marmara University Menopause Outpatient Clinic were enrolled for this prospective cohort study. The women were allocated to one of three groups according to the bone mineral density (BMD) of the lumbar vertebrae and total hip, as measured by dual energy X-ray absorptiometry (DEXA). Serum FSH, estradiol levels, age and time since menopause were compared between the groups. RESULTS The mean serum FSH, LH, estradiol and testosterone levels for women with normal, osteopenic and osteoporotic BMD at lumbar vertrebra L1-L4 and total hip were comparable. Time since menopause had a stronger predictive value for low BMD (osteopenia or osteoporosis) in the lumbar and hip areas than did serum FSH or estradiol levels. CONCLUSIONS Our study showed that neither FSH nor E2 has a strong impact on postmenopausal BMD. However it appears that time since menopause has a weak non-significant association with postmenopausal osteopenia and osteoporosis.
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Affiliation(s)
- Tevfik Yoldemir
- Department of Obstetrics and Gynecology, Marmara University , School of Medicine, Istanbul, Turkey.
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Smith ER, Yeasky T, Wei JQ, Miki RA, Cai KQ, Smedberg JL, Yang WL, Xu XX. White spotting variant mouse as an experimental model for ovarian aging and menopausal biology. Menopause 2012; 19:588-96. [PMID: 22228319 PMCID: PMC3326177 DOI: 10.1097/gme.0b013e318239cc53] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Menopause is a unique phenomenon in modern women, as most mammalian species possess a reproductive period comparable with their life span. Menopause is caused by the depletion of germ cell-containing ovarian follicles and in laboratory studies is usually modeled in animals in which the ovarian function is removed through ovariectomy or chemical poisoning of the germ cells. Our objective was to explore and characterize the white spotting variant (Wv) mice that have reduced ovarian germ cell abundance, a result of a point mutation in the c-kit gene that decreases kinase activity, as a genetic model for use in menopause studies. METHODS Physiological and morphological features associated with menopause were determined in female Wv/Wv mice compared with age-matched wildtype controls. Immunohistochemistry was used to evaluate the presence and number of follicles in paraffin-embedded ovaries. Bone density and body composition were evaluated using the PIXImus x-ray densitometer, and lipids, calcium, and hormone levels were determined in serum using antigen-specific enzyme immunoassays. Heart and body weight were measured, and cardiac function was evaluated using transthoracic echocardiography. RESULTS The ovaries of the Wv/Wv females have a greatly reduced number of normal germ cells at birth compared with wildtype mice. The remaining follicles are depleted by around 2 months, and the ovaries develop benign epithelial lesions that resemble morphological changes that occur during ovarian aging, whereas a normal mouse ovary has numerous follicles at all stages of development and retains some follicles even in advanced age. Wv mice have elevated plasma gonadotropins and reduced estrogen and progesterone levels, a significant reduction in bone mass density, and elevated serum cholesterol and lipoprotein levels. Moreover, the Wv female mice have enlarged hearts and reduced cardiac function. CONCLUSIONS The reduction of c-kit activity in Wv mice leads to a substantially diminished follicular endowment in newborn mice and premature depletion of follicles in young mice, although mutant females have a normal life span after cessation of ovarian function. The Wv female mice exhibit consistent physiological changes that resemble common features of postmenopausal women. These alterations include follicle depletion, morphological aging of the ovary, altered serum levels of cholesterol, gonadotropins and steroid hormones, decreased bone density, and reduced cardiac function. These changes were not observed in male mice, either age-matched male Wv/Wv or wildtype mice, and are improbably caused by global loss of c-kit function. The Wv mouse may be a genetic, intact-ovary model that mimics closely the phenotypes of human menopause to be used for further studies to understand the mechanisms of menopausal biology.
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Affiliation(s)
- Elizabeth R Smith
- Sylvester Comprehensive Cancer Center, Department ofMedicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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High bone density and bone health. ACTA ACUST UNITED AC 2012; 59:207-14. [PMID: 22325788 DOI: 10.1016/j.endonu.2011.10.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 10/21/2011] [Accepted: 10/24/2011] [Indexed: 11/21/2022]
Abstract
The aim of this paper is to review the main aspects related to high bone density (HBD) as well as to discuss the physiologic mechanisms involved in bone health. There are still no well-defined criteria for identification of individuals with HBD and there are few studies on the topic. Most studies demonstrate that overweight, male gender, black ethnic background, physical activity, calcium and fluoride intake and use of medications such as statins and thiazide diuretics play a relevant and positive role on bone mineral density. Moreover, it is known that individuals with certain diseases such as obesity, diabetes, estrogen receptor-positive breast or endometrial cancer have greater bone density than healthy individuals, as well as athletes having higher bone density than non-athletes does not necessarily mean that they have healthy bones. A better understanding of risk and protective factors may help in the management of patients with bone frailty and have applicability in the treatment and in the prevention of osteoporosis, especially intervening on non-modifiable risk factors.
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Casarini L, Pignatti E, Simoni M. Effects of polymorphisms in gonadotropin and gonadotropin receptor genes on reproductive function. Rev Endocr Metab Disord 2011; 12:303-21. [PMID: 21912887 DOI: 10.1007/s11154-011-9192-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gonadotropins, the action of which is mediated at the level of their gonadal receptors, play a key role in sexual development, reproductive functions and in metabolism. The involvement of the gonadotropins and their receptor genotypes on reproductive function are widely studied. A large number of gonadotropins and their receptors gene polymorphisms are known, but the only one considerable as a clear, absolute genetic marker of reproductive features or disfunctions is the FSHR Asn680Ser polymorphism, since it modulates ovarian response to FSH. The aim of these studies would to be the prediction of the genetic causes of sex-related diseases to enable a customized clinical setting based on individual response of patients undergoing gonadotropin stimulation. In this review we discuss the latest information about the effects of polymorphisms of the gonadotropins and their receptor genes on reproductive functions of both male and female, and discuss their patho-physiological implications.
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Affiliation(s)
- Livio Casarini
- Department of Medicine, Endocrinology, Metabolism and Geriatrics, University of Modena and Reggio Emilia, via P. Giardini 1355, 41126 Modena, Italy
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Rouach V, Katzburg S, Koch Y, Stern N, Somjen D. Bone loss in ovariectomized rats: Dominant role for estrogen but apparently not for FSH. J Cell Biochem 2011; 112:128-37. [DOI: 10.1002/jcb.22908] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Elevated follicle-stimulating hormone (FSH) activity is proposed to directly cause bone loss independent of estradiol deficiency in aging women. Using transgenic female mice expressing human FSH (TgFSH), we now reveal that TgFSH dose-dependently increased bone mass, markedly elevating tibial and vertebral trabecular bone volume. Furthermore, TgFSH stimulated a striking accrual of bone mass in hypogonadal mice lacking endogenous FSH and luteinizing hormone (LH) function, showing that FSH-induced bone mass occurred independently of background LH or estradiol levels. Higher TgFSH levels increased osteoblast surfaces in trabecular bone and stimulated de novo bone formation, filling marrow spaces with woven rather than lamellar bone, reflective of a strong anabolic stimulus. Trabecular bone volume correlated positively with ovarian-derived serum inhibin A or testosterone levels in TgFSH mice, and ovariectomy abolished TgFSH-induced bone formation, proving that FSH effects on bone require an ovary-dependent pathway. No detectable FSH receptor mRNA in mouse bone or cultured osteoblasts or osteoclasts indicated that FSH did not directly stimulate bone. Therefore, contrary to proposed FSH-induced bone loss, our findings demonstrate that FSH has dose-dependent anabolic effects on bone via an ovary-dependent mechanism, which is independent of LH activity, and does not involve direct FSH actions on bone cells.
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15
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Wu XY, Wu XP, Luo XH, Xie H, Zhang H, Peng YQ, Yuan LQ, Jiang YB, Liao EY. The relationship between the levels of gonadotropic hormones and OPG, leptin, TGF-β1 and TGF-β2 in Chinese adult women. Clin Chim Acta 2010; 411:1296-305. [DOI: 10.1016/j.cca.2010.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 04/14/2010] [Accepted: 05/06/2010] [Indexed: 12/01/2022]
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16
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Leppänen OV, Sievänen H, Jokihaara J, Pajamäki I, Kannus P, Cooper DM, Järvinen TLN. The effects of loading and estrogen on rat bone growth. J Appl Physiol (1985) 2010; 108:1737-44. [DOI: 10.1152/japplphysiol.00989.2009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study evaluated the contributions of locomotive loading and estrogen to the development of diaphysis of rat femur. A randomized 2 × 2 study design was used. Altogether, 70 female Sprague-Dawley rats were used, of which 10 were euthanized at entry. Of the remaining rats, 16 served as controls, and the rest, 44, underwent a unilateral sciatic neurectomy. The effect of estrogen was removed by ovariectomizing one-half of the neurectomized rats. After 27 wk, the animals were euthanized, and the femora were excised. Irrespective of loading or estrogen, the femur length and mineral mass increased by 142 and 687%, respectively. Axial growth was not modulated either by locomotive loading or estrogen, but the loading resulted in direction-specific changes in the cross-sectional geometry. The estrogen-related gains were evident on the endocortical surface, while the loading-related gains occurred on the periosteal surface. The loading and estrogen were significantly associated with increased bone strength (21 and 15%, respectively) in the mediolateral direction, but not in the anteroposterior direction. Axial growth and accrual of bone mineral mass of the rat femur are largely independent of locomotive loading or estrogen, whereas these factors specifically account for the femur function, as either a mechanical lever or a mineral reservoir for reproduction, respectively.
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Affiliation(s)
- Olli V. Leppänen
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
| | - Harri Sievänen
- The Bone Research Group, UKK Institute, Tampere, Finland
| | - Jarkko Jokihaara
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia; and
| | - Ilari Pajamäki
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
| | - Pekka Kannus
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- The Bone Research Group, UKK Institute, Tampere, Finland
| | - David M. Cooper
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Teppo L. N. Järvinen
- Medical School and the Institute of Medical Technology, University of Tampere,
- Division of Orthopaedics and Traumatology, Department of Trauma, Musculoskeletal Surgery and Rehabilitation, Tampere University Hospital, and
- Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia; and
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17
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Abstract
Hypothalamic gonadotropin-releasing hormone (GnRH) stimulates secretion of pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which directly regulate ovarian function. Pituitary FSH can modulate osteoclast development, and thereby influence bone turnover. Pituitary oxytocin and prolactin effects on the skeleton are not merely limited to pregnancy and lactation; oxytocin stimulates osteoblastogenesis and bone formation, whereas prolactin exerts skeletal effects in an age-dependent manner. Cyclic levels of inhibins and estrogen suppress FSH and LH, respectively, and also suppress bone turnover via their suppressive effects on osteoblast and osteoclast differentiation. However, continuous exposure to inhibins or estrogen/androgens is anabolic for the skeleton in intact animals and protects against gonadectomy-induced bone loss. Alterations of one hormone in the hypothalamic-pituitary-gonadal (HPG) axis influence other bone-active hormones in the entire feedback loop in the axis. Thus, we propose that the action of the HPG axis should be extended to include its combined effects on the skeleton, thus creating the HPG skeletal (HPGS) axis.
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Affiliation(s)
- Kristy M Nicks
- Departments of Physiology and Biophysics and Orthopaedic Surgery, University of Arkansas for Medical Sciences, 4301 West Markham, Slot 505, Little Rock, AR, 72205, USA.
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18
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Wu XY, Wu XP, Xie H, Zhang H, Peng YQ, Yuan LQ, Su X, Luo XH, Liao EY. Age-related changes in biochemical markers of bone turnover and gonadotropin levels and their relationship among Chinese adult women. Osteoporos Int 2010; 21:275-85. [PMID: 19562242 DOI: 10.1007/s00198-009-0943-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2009] [Accepted: 04/10/2009] [Indexed: 11/26/2022]
Abstract
UNLABELLED The relationship between the levels of gonadotropic hormones and bone metabolism in Chinese adult women is unclear. Our research shows that a significant positive correlation exists between the levels of gonadotropic hormones and various bone turnover indicators. Follicle-stimulating hormone (FSH) has been found to have a greater influence on all types of bone turnover indicator than luteinizing hormone (LH). Further, FSH has a greater influence on bone formation indicators than on bone resorption indicators. INTRODUCTION The aim of this study was to investigate the relationship between serum FSH and LH and biochemical markers of bone turnover in native Chinese adult women. METHODS We conducted a cross-sectional study of 694 healthy Chinese women aged between 20 and 82 years. Serum FSH, LH, bone-specific alkaline phosphatase (BAP), osteocalcin (OC), N-terminal telopeptides of type I collagen, C-terminal telopeptides of type I collagen, urinary NTX, urinary CTX, and urinary deoxypyridinoline (uDPD) were determined. RESULTS All types of bone turnover indicator were significantly positively correlated with FSH (r = 0.164-0.626, all P = 0.000) and LH (r = 0.130-0.618, all P = 0.013-0.000). The correlation coefficient between serum FSH and BAP was the highest (r = 0.626), and that between serum FSH and uDPD was the lowest (r = 0.164). The serum gonadotropic hormone levels were higher; concentrations of bone turnover indicators were higher. The extent of the influence of FSH on various bone turnover indicators was approximately seven to 20 times greater than that of LH on these indicators. FSH could explain 43% and 22% of the changes in BAP and OC, respectively; whereas, LH could explain only 2.1% and 1.1%, respectively. FSH could explain approximately 1.9-11.8% of the changes in bone resorption indicators; however, LH had almost no effect on them. CONCLUSIONS Gonadotropic hormone levels are correlated with the rate of bone turnover in Chinese women: the higher the serum gonadotropic hormone levels in circulation, the higher the levels of bone turnover indicators. FSH has a greater influence on all types of bone turnover indicator than LH; moreover, it has a greater influence on bone formation indicators than on bone resorption indicators.
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Affiliation(s)
- X-Y Wu
- Institute of Metabolism and Endocrinology, The Second Xiang-Ya Hospital, Central South University, 139 Renmin-Zhong Rd, Changsha, 410011 Hunan, People's Republic of China
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19
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Is there an association between vasomotor symptoms and both low bone density and cardiovascular risk? Menopause 2009; 16:219-23. [PMID: 19188853 DOI: 10.1097/gme.0b013e318199404a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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20
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Horner KC. The effect of sex hormones on bone metabolism of the otic capsule – an overview. Hear Res 2009; 252:56-60. [DOI: 10.1016/j.heares.2008.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 11/28/2008] [Accepted: 12/04/2008] [Indexed: 01/23/2023]
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21
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Postpubertal architectural developmental patterns differ between the L3 vertebra and proximal tibia in three inbred strains of mice. J Bone Miner Res 2008; 23:2048-59. [PMID: 18684086 DOI: 10.1359/jbmr.080808] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An understanding of normal microarchitectural bone development patterns of common murine models is needed. Longitudinal, structural, and mineralization trends were evaluated by in vivo microCT over 12 time points from 6-48 wk of age at the vertebra and tibia of C3H/HeN, C57BL/6, and BALB/C mice. Longitudinal growth occurred rapidly until 8-10 wk, slowed as the growth plate bridged, and fused at 8-10 mo. Structural augmentation occurred through formation of trabeculae at the growth plate and thickening of existing ones. In the vertebrae, BV/TV increased rapidly until 12 wk in all strains. Between 12 and 32 wk, the architecture was stable with BV/TV deviating <1.1%, 1.6%, and 3.4% for the C57BL/6, BALB/C, and C3H/HeN mice. In contrast, the tibial architecture changed continuously but more moderately for BV/TV and TbTh compared with the vertebra and with comparable or larger changes for TbN and TbSp. Age-related trabecular deterioration (decreased BV/TV and TbN; increased TbSp and structure model index) was evident at both sites at 32 wk. In all strains, the cortex continued to develop after trabecular values peaked. The temporal plateau of BMD was variable across mouse strains and site, whereas tissue mineral density was attained at approximately 6 mo for all sites and strains. Geometric changes at the tibial diaphysis occurred rapidly until 8-10 wk, providing the C57BL/6 mice and C3H/HeN mice with the highest torsional and compressive rigidity, respectively. In summary, key skeletal development milestones were identified, and architectural topology at the vertebra was found to be more stable than at the tibia.
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22
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Mansell JP. Bone phenotypes in response to gonadotropin misexpression: the role for gonadotropins in postmenopausal osteoporosis. Int J Gen Med 2008; 1:51-7. [PMID: 20428406 PMCID: PMC2840536 DOI: 10.2147/ijgm.s3879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Scant attention has been paid to the potential role of gonadotropins in bone tissue homeostasis. The focus on estrogen and estrogen replacement therapy for osteoporosis as far back as the 1940's may account for the paucity of gonadotropin studies in bone biology. It is conceivable that prevailing dogma may have subconsciously steered us away from addressing whether gonadotropins have a place in skeletal physiology. However an examination of bone tissue catabolism in ovariectomized (OVX) and luteinizing hormone-releasing hormone (LHRH) agonist (Zoladex((R)))-treated rats generated some interesting and conflicting data; Zoladex-treated rats, unlike the OVX group, failed to exhibit increased bone collagen catabolism despite clear evidence for estrogen deficiency. The findings, although controversial, supported the possibility that elevated gonadotropins in the OVX model were in some way accountable for increased bone catabolism. In response to these initial findings further studies were performed to determine if altered LH status may in some way impact on the skeleton To this end an investigation of bone mass and histomorphometry were conducted in LH receptor nullizygous mice and human chorionic gonadotropin (hCG) overexpressing mice. There were clear phenotypic differences; the LH receptor knockout mice displayed reduced bone mass whereas the hCG overexpressing animals had stark increases in bone mass. Much more recently the team of the Mount Sinai Bone Program have made a significant discovery that bone-resorbing osteoclasts express receptors for follicle-stimulating hormone (FSH) and that mice nullizygous for FSH receptor are resistant to bone loss despite severe estrogen deficiency. Details of these fascinating models will be presented together with additional findings that give credence for exploring gonadotropin action on the skeleton as we enter the twilight of this Decade of the Bone and Joint.
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Affiliation(s)
- Jason P Mansell
- Department of Oral and Dental Sciences, Division of Oral Medicine, University of Bristol Dental School, Lower Maudlin Street, Bristol, BS1 2LY, UK
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23
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Xu ZR, Wang AH, Wu XP, Zhang H, Sheng ZF, Wu XY, Xie H, Luo XH, Liao EY. Relationship of age-related concentrations of serum FSH and LH with bone mineral density, prevalence of osteoporosis in native Chinese women. Clin Chim Acta 2008; 400:8-13. [PMID: 18930719 DOI: 10.1016/j.cca.2008.09.027] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/09/2008] [Accepted: 09/24/2008] [Indexed: 11/25/2022]
Abstract
BACKGROUND Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) may play an important role in bone mass regulation in postmenopausal women. METHODS A cross-sectional study of 699 healthy Chinese women, aged 20 to 82 y, was conducted. Serum FSH and LH and BMD were measured at the posteroanterior (PA) spine, lateral spine, total hip, and distal forearm. RESULTS The geometric mean values (+/-SD) of serum FSH and LH in premenopausal women were 3.94 +/- 2.08 and 7.51 +/- 2.58 IU/l, respectively, and in postmenopausal women were 28.8 +/- 1.88 and 25.6 +/- 1.95 IU/l, respectively. The correlation of FSH to BMD at different skeletal regions (r = -0.597 - -0.492, P = 0.000) was higher than that of LH to BMD (r = -0.452 - -0.332, P = 0.000). The prevalences of osteoporosis for the quartiles of FSH at various skeletal sites were 0.57%, 0.43%, 27.1%, and 30.9%, respectively; and of LH were 2.14%, 4.43%, 19.5%, and 26.0%, respectively. The prevalence of osteoporosis in 3rd and 4th quartile was more significantly increased than the 1st and 2nd quartile. CONCLUSIONS These data suggest that FSH and LH levels in circulation are associated with BMD changes and osteoporosis occurrence in Chinese women.
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Affiliation(s)
- Zhang-Rong Xu
- Institute of Metabolism and Endocrinology, The Second Xiang-Ya Hospital, Central South University, 139 Renmin-Zhong Rd, Changsha, Hunan 410011, PR China
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24
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A soluble activin type IIA receptor induces bone formation and improves skeletal integrity. Proc Natl Acad Sci U S A 2008; 105:7082-7. [PMID: 18460605 DOI: 10.1073/pnas.0711263105] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Diseases that affect the regulation of bone turnover can lead to skeletal fragility and increased fracture risk. Members of the TGF-beta superfamily have been shown to be involved in the regulation of bone mass. Activin A, a TGF-beta signaling ligand, is present at high levels in bone and may play a role in the regulation of bone metabolism. Here we demonstrate that pharmacological blockade of ligand signaling through the high affinity receptor for activin, type II activin receptor (ActRIIA), by administration of the soluble extracellular domain of ActRIIA fused to a murine IgG2a-Fc, increases bone formation, bone mass, and bone strength in normal mice and in ovariectomized mice with established bone loss. These observations support the development of this pharmacological strategy for the treatment of diseases with skeletal fragility.
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25
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Affiliation(s)
- Graham R Williams
- Molecular Endocrinology Group, Medical Research Council Clinical Sciences Centre, Hammersmith Hospital, Du Cane Road, London W12 0NN, United Kingdom.
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26
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Gao J, Tiwari-Pandey R, Samadfam R, Yang Y, Miao D, Karaplis AC, Sairam MR, Goltzman D. Altered ovarian function affects skeletal homeostasis independent of the action of follicle-stimulating hormone. Endocrinology 2007; 148:2613-21. [PMID: 17332067 DOI: 10.1210/en.2006-1404] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Osteoporosis is a leading public health problem. Although a major cause in women is thought to be a decline in estrogen, it has recently been proposed that FSH or follitropin is required for osteoporotic bone loss. We examined the FSH receptor null mouse (FORKO mouse) to determine whether altered ovarian function could induce bone loss independent of FSH action. By 3 months of age, FORKO mice developed age-dependent declines in bone mineral density and trabecular bone volume of the lumbar spine and femur, which could be partly reversed by ovarian transplantation. Bilateral ovariectomy reduced elevated circulating testosterone levels in FORKO mice and decreased bone mass to levels indistinguishable from those in ovariectomized wild-type controls. Androgen receptor blockade and especially aromatase inhibition each produced bone volume reductions in the FORKO mouse. The results indicate that ovarian secretory products, notably estrogen, and peripheral conversion of ovarian androgen to estrogen can alter bone homeostasis independent of any bone resorptive action of FSH.
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Affiliation(s)
- Jianjun Gao
- Calcium Research Laboratory, McGill University Health Centre, 687 Pine Avenue West, Montreal, Quebec, Canada
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27
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Perrien DS, Akel NS, Edwards PK, Carver AA, Bendre MS, Swain FL, Skinner RA, Hogue WR, Nicks KM, Pierson TM, Suva LJ, Gaddy D. Inhibin A is an endocrine stimulator of bone mass and strength. Endocrinology 2007; 148:1654-65. [PMID: 17194739 DOI: 10.1210/en.2006-0848] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gonadal function plays a major role in bone homeostasis. It is widely held that the skeletal consequences of hypogonadism are solely due to a loss of sex steroids; however, increases in bone turnover begin during perimenopause before decreases in serum estradiol levels. These data and our demonstration that inhibins acutely regulate bone cell differentiation in vitro led us to test whether inhibin A (InhA) regulates bone mass in vivo. Using a transgenic model of inducible human InhA expression, InhA increased total body bone mineral density, increased bone volume, and improved biomechanical properties at the proximal tibia in intact mice and also prevented the loss of BMD and bone volume and strength associated with gonadectomy at both the spine and proximal tibia. In addition, InhA increased mineral apposition rate, double-labeled surface, and serum osteocalcin levels in vivo and osteoblastogenesis ex vivo without affecting osteoclast number or activity. Together these results demonstrate novel stimulatory effects of InhA on the skeleton in vivo. These studies provide in vivo evidence demonstrating that gonadal factors other than sex steroids play an important role in regulating bone mass and strength and, combined with our previous clinical data, suggest that gonadal InhA may be a component of the normal endocrine repertoire that regulates bone quality in both the axial and appendicular skeleton.
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Affiliation(s)
- Daniel S Perrien
- Department of Physiology and Biophysics, Center for Orthopaedic Research, University of Arkansas for Medical Sciences, 4301 West Markham, Slot 505, Little Rock, Arkansas 72205, USA
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28
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Perez GI, Jurisicova A, Wise L, Lipina T, Kanisek M, Bechard A, Takai Y, Hunt P, Roder J, Grynpas M, Tilly JL. Absence of the proapoptotic Bax protein extends fertility and alleviates age-related health complications in female mice. Proc Natl Acad Sci U S A 2007; 104:5229-34. [PMID: 17360389 PMCID: PMC1817832 DOI: 10.1073/pnas.0608557104] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The menopausal transition in human females, which is driven by a loss of cyclic ovarian function, occurs around age 50 and is thought to underlie the emergence of an array of health problems in aging women. Although mice do not undergo a true menopause, female mice exhibit ovarian failure long before death because of chronological age and subsequently develop many of the same age-associated health complications observed in postmenopausal women. Here we show in mice that inactivation of the proapoptotic Bax gene, which sustains ovarian lifespan into advanced age, extends fertile potential and minimizes many age-related health problems, including bone and muscle loss, excess fat deposition, alopecia, cataracts, deafness, increased anxiety, and selective attention deficit. Further, ovariectomy studies show that the health benefits gained by aged females from Bax deficiency reflect a complex interplay between ovary-dependent and -independent pathways. Importantly, and contrary to popular belief, prolongation of ovarian function into advanced age by Bax deficiency did not lead to an increase in tumor incidence. Thus, the development of methods for postponing ovarian failure at menopause may represent an attractive option for improving the quality of life in aging females.
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Affiliation(s)
- Gloria I. Perez
- *Vincent Center for Reproductive Biology, Vincent Obstetrics and Gynecology Service, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114
| | - Andrea Jurisicova
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Lisa Wise
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Tatiana Lipina
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Marijana Kanisek
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Allison Bechard
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Yasushi Takai
- *Vincent Center for Reproductive Biology, Vincent Obstetrics and Gynecology Service, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114
| | - Patricia Hunt
- Center for Reproductive Biology and School of Molecular Biosciences, Washingston State University, Pullman, WA 99164
| | - John Roder
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Marc Grynpas
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada M5G 1X5; and
| | - Jonathan L. Tilly
- *Vincent Center for Reproductive Biology, Vincent Obstetrics and Gynecology Service, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114
- To whom correspondence should be addressed. E-mail:
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29
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Prior JC. FSH and bone--important physiology or not? Trends Mol Med 2006; 13:1-3. [PMID: 17141571 DOI: 10.1016/j.molmed.2006.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 11/03/2006] [Accepted: 11/20/2006] [Indexed: 11/17/2022]
Abstract
For many years, osteoporosis in women was equated with estrogen deficiency. The recent articles by Zaidi and colleagues offer a new challenge to the estrogen-deficiency-osteoporosis hypothesis by showing that follicle-stimulating hormone (FSH) stimulates osteoclastic bone resorption perhaps through tumor necrosis factor-alpha (TNF-alpha). These authors, however, neglected to mention bone abnormalities and high testosterone levels that were previously shown in FSH-receptor knockout and other modified mice. It is also possible that they have overemphasized potential relationships of these new data with human bone loss. Despite these fascinating data, the paradigm of FSH causing hypogonadal bone loss is not yet ready to displace the estrogen-deficiency-osteoporosis paradigm, although that model already faces considerable challenge.
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Affiliation(s)
- Jerilynn C Prior
- Endocrinology and Metabolism, Centre for Menstrual Cycle and Ovulation Research, University of British Columbia, Vancouver Coastal Health Research Institute, Vancouver V5Z 1M9, Canada.
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