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Bone Mass and Osteoblast Activity Are Sex-Dependent in Mice Lacking the Estrogen Receptor α in Chondrocytes and Osteoblast Progenitor Cells. Int J Mol Sci 2022; 23:ijms23052902. [PMID: 35270044 PMCID: PMC8911122 DOI: 10.3390/ijms23052902] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 01/11/2023] Open
Abstract
While estrogen receptor alpha (ERα) is known to be important for bone development and homeostasis, its exact function during osteoblast differentiation remains unclear. Conditional deletion of ERα during specific stages of osteoblast differentiation revealed different bone phenotypes, which were also shown to be sex-dependent. Since hypertrophic chondrocytes can transdifferentiate into osteoblasts and substantially contribute to long-bone development, we aimed to investigate the effects of ERα deletion in both osteoblast and chondrocytes on bone development and structure. Therefore, we generated mice in which the ERα gene was inactivated via a Runx2-driven cyclic recombinase (ERαfl/fl; Runx2Cre). We analyzed the bones of 3-month-old ERαfl/fl; Runx2Cre mice by biomechanical testing, micro-computed tomography, and cellular parameters by histology. Male ERαfl/fl; Runx2Cre mice displayed a significantly increased cortical bone mass and flexural rigidity of the femurs compared to age-matched controls with no active Cre-transgene (ERαfl/fl). By contrast, female ERαfl/fl; Runx2Cre mice exhibited significant trabecular bone loss, whereas in cortical bone periosteal and endosteal diameters were reduced. Our results indicate that the ERα in osteoblast progenitors and hypertrophic chondrocytes differentially contributes to bone mass regulation in male and female mice and improves our understanding of ERα signaling in bone cells in vivo.
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2
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Steppe L, Krüger BT, Tschaffon MEA, Fischer V, Tuckermann J, Ignatius A, Haffner-Luntzer M. Estrogen Receptor α Signaling in Osteoblasts is Required for Mechanotransduction in Bone Fracture Healing. Front Bioeng Biotechnol 2021; 9:782355. [PMID: 34950644 PMCID: PMC8689144 DOI: 10.3389/fbioe.2021.782355] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022] Open
Abstract
Biomechanical stimulation by whole-body low-magnitude high-frequency vibration (LMHFV) has demonstrated to provoke anabolic effects on bone metabolism in both non-osteoporotic and osteoporotic animals and humans. However, preclinical studies reported that vibration improved fracture healing and bone formation in osteoporotic, ovariectomized (OVX) mice representing an estrogen-deficient hormonal status, but impaired bone regeneration in skeletally healthy non-OVX mice. These effects were abolished in general estrogen receptor α (ERα)-knockout (KO) mice. However, it remains to be elucidated which cell types in the fracture callus are targeted by LMHFV during bone healing. To answer this question, we generated osteoblast lineage-specific ERα-KO mice that were subjected to ovariectomy, femur osteotomy and subsequent vibration. We found that the ERα specifically on osteoblastic lineage cells facilitated the vibration-induced effects on fracture healing, because in osteoblast lineage-specific ERα-KO (ERαfl/fl; Runx2Cre) mice the negative effects in non-OVX mice were abolished, whereas the positive effects of vibration in OVX mice were reversed. To gain greater mechanistic insights, the influence of vibration on murine and human osteogenic cells was investigated in vitro by whole genome array analysis and qPCR. The results suggested that particularly canonical WNT and Cox2/PGE2 signaling is involved in the mechanotransduction of LMHFV under estrogen-deficient conditions. In conclusion, our study demonstrates a critical role of the osteoblast lineage-specific ERα in LMHFV-induced effects on fracture healing and provides further insights into the molecular mechanism behind these effects.
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Affiliation(s)
- Lena Steppe
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Benjamin Thilo Krüger
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | | | - Verena Fischer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology (CME), Ulm University, Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
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3
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Sakai Y, Kato K, Koyama H, Kuba A, Takahashi H, Fujimori T, Hatta M, Negri AP, Baird AH, Ueno N. A step-down photophobic response in coral larvae: implications for the light-dependent distribution of the common reef coral, Acropora tenuis. Sci Rep 2020; 10:17680. [PMID: 33077782 PMCID: PMC7572417 DOI: 10.1038/s41598-020-74649-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/05/2020] [Indexed: 11/10/2022] Open
Abstract
Behavioral responses to environmental factors at the planktonic larval stage can have a crucial influence on habitat selection and therefore adult distributions in many benthic organisms. Reef-building corals show strong patterns of zonation across depth or underwater topography, with different suites of species aggregating in different light environments. One potential mechanism driving this pattern is the response of free-swimming larvae to light. However, there is little experimental support for this hypothesis; in particular, there are few direct and quantitative observations of larval behavior in response to light. Here, we analyzed the swimming behavior of larvae of the common reef coral Acropora tenuis under various light conditions. Larvae exhibited a step-down photophobic response, i.e. a marked decrease in swimming speed, in response to a rapid attenuation (step-down) of light intensity. Observations of larvae under different wavelengths indicated that only the loss of blue light (wavelengths between 400 and 500 nm) produced a significant response. Mathematical simulations of this step-down photophobic response indicate that larvae will aggregate in the lighter areas of two-dimensional large rectangular fields. These results suggest that the step-down photophobic response of coral larvae may play an important role in determining where larval settle on the reef.
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Affiliation(s)
- Yusuke Sakai
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan. .,Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan.
| | - Kagayaki Kato
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan.,Department of Imaging Science, Center for Novel Science Initiatives, National Institute for Basic Biology, Okazaki, Aichi, Japan.,Division of Evolutionary Biology Biodiversity, National Institute for Basic Biology, Okazaki, Aichi, Japan
| | - Hiroshi Koyama
- Division of Embryology, National Institute for Basic Biology, Okazaki, Aichi, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Alyson Kuba
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Hiroki Takahashi
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Toshihiko Fujimori
- Division of Embryology, National Institute for Basic Biology, Okazaki, Aichi, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Masayuki Hatta
- Department of Biology, Ochanomizu University, Bunkyo-ku, Tokyo, Japan
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, QLD, Australia
| | - Andrew H Baird
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia
| | - Naoto Ueno
- Division of Morphogenesis, National Institute for Basic Biology, Okazaki, Aichi, Japan. .,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan.
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4
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Chen Z, Yang P, Wu Y, Liu X, Yang Y, Song P, Chen YT, Lin C, Xu Q. Serum Uric Acid Shows Inverted "U" Type Correlation with Osteoporosis in Chinese Ankylosing Spondylitis Patients: A Retrospective Study. Med Sci Monit 2019; 25:9702-9711. [PMID: 31851643 PMCID: PMC6930702 DOI: 10.12659/msm.918766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background This study was to investigate the correlation between osteoporosis and serum uric acid in ankylosing spondylitis (AS) patients, and to further identify potential factors that might be associated with osteoporosis in AS patients. Material/Methods We included 182 AS patients, consisted of 143 male patients and 39 female patients, who visited our hospital from January 1, 2014 to December 31, 2018. We used dual-energy x-ray absorptiometry to measure bone mineral density (BMD) of orthotopic lumbar vertebrae in patients with AS. The gender, age, disease duration, BMD, T-score, Z-score, uric acid, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), blood platelet (PLT), and status of treatment with biologics of the patients were collected. Then, the Spearman correlation coefficient and multivariate liner regression analysis were applied to identify the relationship between the factors and BMD, T-score, and Z-score in AS patients. Results Male AS patients between the ages of 16 and 30 years old had a higher risk of osteoporosis (P<0.05). AS patients with uric acid value between 300–360 μmol/L had the highest BMD, T-score, and Z-score. The BMD had a positive correlation with age and disease duration (P<0.01) while had a negative correlation with PLT (P<0.05). BMD in AS patients with elevated ESR was significantly (P<0.05) lower than in AS patients with normal ESR. There were no significant differences in BMD between AS patients with elevated CRP and the patients with normal CRP and PLT. Treatment with TNFi (tumor necrosis factor alpha inhibitor) did not improve BMD in AS patients. Conclusions The relationship between uric acid and BMD in AS patients was observed as inverted “U”-type. Keeping uric acid within 300–360 μmol/L might be helpful in preventing AS patients from developing osteoporosis.
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Affiliation(s)
- Zhixin Chen
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland).,Department of Chinese Medicine, South China Agricultural University Hospital, Guangzhou, Guangdong, China (mainland)
| | - Peidan Yang
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland)
| | - Yuyun Wu
- Guangzhou Bai Yun Shan Chen Li Ji Pharmaceutical Factory Co., Ltd., Guangzhou, Guangdong, China (mainland)
| | - Xiaobao Liu
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland).,Department of Rheumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland)
| | - Yechun Yang
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland).,Department of Rheumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland)
| | - Pingfang Song
- Department of Rheumatology, Oregon Health and Science University, Portland, OR, USA
| | | | - Changsong Lin
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland).,Department of Rheumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland)
| | - Qiang Xu
- Department of Rheumatology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland).,Department of Rheumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China (mainland)
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Yorgan TA, Peters S, Amling M, Schinke T. Osteoblast-specific expression of Panx3 is dispensable for postnatal bone remodeling. Bone 2019; 127:155-163. [PMID: 31202927 DOI: 10.1016/j.bone.2019.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 12/11/2022]
Abstract
Since cost-effective osteoanabolic treatment options remain to be established, it is relevant to identify specific molecules physiologically regulating osteoblast differentiation and/or activity that are principally accessible as drug targets. Specific or predominant gene expression in a given cell type often predicts a relevant function in the respective tissue. Thus, we aimed to identify genes encoding membrane-associated proteins with selective expression in differentiated osteoblasts. We therefore applied an unbiased approach, i.e. Affymetrix Gene Chip hybridization, to compare global gene expression in primary murine osteoblasts at two stages of differentiation. For the most strongly induced genes we analyzed their expression pattern in different tissues, which led us to identify known and unknown osteoblast differentiation markers with predominant expression in bone. One of these genes was Panx3, encoding a transmembrane hemichannel with ill-defined function in skeletal remodeling. To decipher the role of Panx3 in osteoblasts we first generated Panx3-fl/fl mice carrying a Runx2-Cre transgene. Using undecalcified histology followed by bone-specific histomorphometry we did not observe any significant difference between 24 weeks old Cre-negative and Cre-positive littermates. We additionally generated and analyzed mice with ubiquitous Panx3 deletion, where a delay of endochondral ossification did not translate into a detectable skeletal phenotype after weaning, possibly explained by compensatory induction of Panx1. Of note, newborn Panx3-deficient mice displayed significantly reduced serum glucose levels, which was not the case in older animals. Our findings demonstrate that Panx3 expression in osteoblasts is not required for postnatal bone remodeling, which essentially rules out its suitability as a target protein for osteoanabolic medication.
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Affiliation(s)
- Timur A Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Stephanie Peters
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg 20246, Germany.
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6
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Abstract
In both sexes, estrogen is one of the most essential hormones for maintaining bone integrity. Also, especially in men, androgen has beneficial effects on bone independent of estrogen. However, estrogen replacement therapy for postmenopausal women increases the risk of developing breast cancer and endometrial cancer, and androgen replacement therapy for partial androgen deficiency of the aging male increases the risk of developing prostate cancer. Various mechanisms have been proposed on the effects of gonadal hormones on bone, such as effects through cytokines including IL-6 and effects on the OPG/RANKL ratio. In addition, large amounts of new information deriving from high-throughput gene expression analysis raise the possibility of multiple other effects on bone cells. Both estrogen and androgen exert their effects via the estrogen receptor (ER) or the androgen receptor (AR), which belongs to the nuclear receptor superfamily. Compounds such as selective estrogen receptor modulators (SERMs) and selective androgen receptor modulators (SARMs) also bind ER and AR, respectively. However, SERMs and SARMs alter the ER or AR structure differently from estrogen or androgen, resulting in other downstream gene responses. As a result they can exert favorable effects on bone while suppressing the undesirable actions of estrogen and androgen. Elucidation of ER and AR ligand-specific and tissue-specific gene regulation mechanisms will also provide information on the signal transduction mechanisms of other nuclear receptors and will be valuable for the development of new therapeutic agents.
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7
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Hoffmann DB, Gruber J, Böker KO, Deppe D, Sehmisch S, Schilling AF, Lemus-Diaz N, Komrakova M, Schneider S. Effects of RANKL Knockdown by Virus-like Particle-Mediated RNAi in a Rat Model of Osteoporosis. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 12:443-452. [PMID: 30195781 PMCID: PMC6041464 DOI: 10.1016/j.omtn.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 06/03/2018] [Accepted: 06/05/2018] [Indexed: 02/06/2023]
Abstract
Rebalancing of the RANKL/OPG system seems to be an effective treatment strategy in postmenopausal osteoporosis. Here, we evaluate the knockdown of RANKL by in-vivo-delivered siRNA in a rat model of osteoporosis. Virus-like-particles (VLPs) derived from polyoma JC virus were used for delivering RANKL siRNA in ovariectomized (OVX) rats. 48 rats were ovariectomized and treated with either 17β-estradiol (E2), VLPs containing RANKL siRNA (siRANKL), or VLPs containing non-cognate siRNA (siCtrl). All OVX groups were subdivided into the prophylaxis group (PG) and the therapy group (TG). The PG received treatment directly after being OVX for 10 weeks. The TG received treatment 5 weeks after being OVX for 5 weeks. Rats were sacrificed 10 weeks after being OVX. Bone and blood samples were analyzed. E2 and siRANKL showed a significant knockdown of RANKL mRNA. A protein knockdown was observed with E2 and siRANKL in the TG but not in the PG. No distinct improvements in biomechanical and morphological properties of the bones were observed after siRANKL treatment. In the PG, E2 protected the bone structure. We demonstrated successful mRNA and protein knockdown by VLP-mediated RNAi in vivo. Knockdown of membranous RANKL did not result in significant improvements of bone properties in this model of early-stage postmenopausal osteoporosis.
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Affiliation(s)
- Daniel B Hoffmann
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany.
| | - Jens Gruber
- Primate Genetics Laboratory, Junior Research Group "Medical RNA Biology," German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | - Kai O Böker
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany; Primate Genetics Laboratory, Junior Research Group "Medical RNA Biology," German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | - Delia Deppe
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany
| | - Stephan Sehmisch
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany
| | - Arndt F Schilling
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany
| | - Nicolas Lemus-Diaz
- Primate Genetics Laboratory, Junior Research Group "Medical RNA Biology," German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
| | - Marina Komrakova
- Department of Trauma Surgery, Orthopaedics and Plastic Surgery, University Medical Center Goettingen, Robert Koch Str. 40, 37075 Goettingen, Germany
| | - Stefan Schneider
- Primate Genetics Laboratory, Junior Research Group "Medical RNA Biology," German Primate Center, Kellnerweg 4, 37077 Göttingen, Germany
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8
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Mandourah AY, Ranganath L, Barraclough R, Vinjamuri S, Hof RV, Hamill S, Czanner G, Dera AA, Wang D, Barraclough DL. Circulating microRNAs as potential diagnostic biomarkers for osteoporosis. Sci Rep 2018; 8:8421. [PMID: 29849050 PMCID: PMC5976644 DOI: 10.1038/s41598-018-26525-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/14/2018] [Indexed: 12/12/2022] Open
Abstract
Osteoporosis is the most common age-related bone disease worldwide and is usually clinically asymptomatic until the first fracture happens. MicroRNAs are critical molecular regulators in bone remodelling processes and are stabilised in the blood. The aim of this project was to identify circulatory microRNAs associated with osteoporosis using advanced PCR arrays initially and the identified differentially-expressed microRNAs were validated in clinical samples using RT-qPCR. A total of 161 participants were recruited and 139 participants were included in this study with local ethical approvals prior to recruitment. RNAs were extracted, purified, quantified and analysed from all serum and plasma samples. Differentially-expressed miRNAs were identified using miRNA PCR arrays initially and validated in 139 serum and 134 plasma clinical samples using RT-qPCR. Following validation of identified miRNAs in individual clinical samples using RT-qPCR, circulating miRNAs, hsa-miR-122-5p and hsa-miR-4516 were statistically significantly differentially-expressed between non-osteoporotic controls, osteopaenia and osteoporosis patients. Further analysis showed that the levels of these microRNAs were associated with fragility fracture and correlated with the low bone mineral density in osteoporosis patients. The results show that circulating hsa-miR-122-5p and hsa-miR-4516 could be potential diagnostic biomarkers for osteoporosis in the future.
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Affiliation(s)
- Abdullah Y Mandourah
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, United Kingdom.,Al Hada Armed Forces Hospital, Taif, Saudi Arabia
| | - Lakshminarayan Ranganath
- Department of Clinical Biochemistry and Metabolic Medicine, The Royal Liverpool and Broadgreen University Hospital NHS Trust, Prescot Street, Liverpool, L7 8XP, United Kingdom
| | - Roger Barraclough
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Sobhan Vinjamuri
- Department Of Nuclear Medicine, The Royal Liverpool and Broadgreen University Hospital NHS Trust, Prescot Street, Liverpool, L7 8XP, United Kingdom
| | - Robert Van'T Hof
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, United Kingdom
| | - Sandra Hamill
- Department Of Nuclear Medicine, The Royal Liverpool and Broadgreen University Hospital NHS Trust, Prescot Street, Liverpool, L7 8XP, United Kingdom
| | - Gabriela Czanner
- Department of Biostatistics and Eye and Vision Science, Faculty of Health and Life Sciences, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, United Kingdom
| | - Ayed A Dera
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, United Kingdom.,Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
| | - Duolao Wang
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, United Kingdom
| | - Dong L Barraclough
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, United Kingdom.
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9
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Haffner-Luntzer M, Kovtun A, Lackner I, Mödinger Y, Hacker S, Liedert A, Tuckermann J, Ignatius A. Estrogen receptor α- (ERα), but not ERβ-signaling, is crucially involved in mechanostimulation of bone fracture healing by whole-body vibration. Bone 2018; 110:11-20. [PMID: 29367057 DOI: 10.1016/j.bone.2018.01.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/21/2017] [Accepted: 01/14/2018] [Indexed: 02/07/2023]
Abstract
Mechanostimulation by low-magnitude high frequency vibration (LMHFV) has been shown to provoke anabolic effects on the intact skeleton in both mice and humans. However, experimental studies revealed that, during bone fracture healing, the effect of whole-body vibration is profoundly influenced by the estrogen status. LMHFV significantly improved fracture healing in ovariectomized (OVX) mice being estrogen deficient, whereas bone regeneration was significantly reduced in non-OVX, estrogen-competent mice. Furthermore, estrogen receptors α (ERα) and β (ERβ) were differentially expressed in the fracture callus after whole-body vibration, depending on the estrogen status. Based on these data, we hypothesized that ERs may mediate vibration-induced effects on fracture healing. To prove this hypothesis, we investigated the effects of LMHFV on bone healing in mice lacking ERα or ERβ. To study the influence of the ER ligand estrogen, both non-OVX and OVX mice were used. All mice received a femur osteotomy stabilized by an external fixator. Half of the mice were sham-operated or subjected to OVX 4 weeks before osteotomy. Half of each group received LMHFV with 0.3 g and 45 Hz for 20 min per day, 5 days per week. After 21 days, fracture healing was evaluated by biomechanical testing, μCT analysis, histomorphometry and immunohistochemistry. Absence of ERα or ERβ did not affect fracture healing in sham-treated mice. Wildtype (WT) and ERβ-knockout mice similarly displayed impaired bone regeneration after OVX, whereas ERα-knockout mice did not. Confirming previous data, in WT mice, LMHFV negatively affected bone repair in non-OVX mice, whereas OVX-induced compromised healing was significantly improved by vibration. In contrast, vibrated ERα-knockout mice did not display significant differences in fracture healing compared to non-vibrated animals, both in non-OVX and OVX mice. Fracture healing in ERβ-knockout mice was similarly affected by LMHFV as in WT mice. These results suggest that ERα-signaling may be crucial for vibration-induced effects on fracture healing, whereas ERβ-signaling may play a minor role.
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Affiliation(s)
- Melanie Haffner-Luntzer
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany.
| | - Anna Kovtun
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Ina Lackner
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Yvonne Mödinger
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Steffen Hacker
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Astrid Liedert
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
| | - Jan Tuckermann
- Institute of Comparative Molecular Endocrinology, Ulm University, Helmholtzstraße 8, 89081 Ulm, Germany
| | - Anita Ignatius
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Helmholtzstraße 14, 89081 Ulm, Germany
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10
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Okamoto K, Nakashima T, Shinohara M, Negishi-Koga T, Komatsu N, Terashima A, Sawa S, Nitta T, Takayanagi H. Osteoimmunology: The Conceptual Framework Unifying the Immune and Skeletal Systems. Physiol Rev 2017; 97:1295-1349. [DOI: 10.1152/physrev.00036.2016] [Citation(s) in RCA: 241] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/29/2017] [Accepted: 04/04/2017] [Indexed: 12/13/2022] Open
Abstract
The immune and skeletal systems share a variety of molecules, including cytokines, chemokines, hormones, receptors, and transcription factors. Bone cells interact with immune cells under physiological and pathological conditions. Osteoimmunology was created as a new interdisciplinary field in large part to highlight the shared molecules and reciprocal interactions between the two systems in both heath and disease. Receptor activator of NF-κB ligand (RANKL) plays an essential role not only in the development of immune organs and bones, but also in autoimmune diseases affecting bone, thus effectively comprising the molecule that links the two systems. Here we review the function, gene regulation, and signal transduction of osteoimmune molecules, including RANKL, in the context of osteoclastogenesis as well as multiple other regulatory functions. Osteoimmunology has become indispensable for understanding the pathogenesis of a number of diseases such as rheumatoid arthritis (RA). We review the various osteoimmune pathologies, including the bone destruction in RA, in which pathogenic helper T cell subsets [such as IL-17-expressing helper T (Th17) cells] induce bone erosion through aberrant RANKL expression. We also focus on cellular interactions and the identification of the communication factors in the bone marrow, discussing the contribution of bone cells to the maintenance and regulation of hematopoietic stem and progenitors cells. Thus the time has come for a basic reappraisal of the framework for understanding both the immune and bone systems. The concept of a unified osteoimmune system will be absolutely indispensable for basic and translational approaches to diseases related to bone and/or the immune system.
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Affiliation(s)
- Kazuo Okamoto
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Tomoki Nakashima
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Masahiro Shinohara
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Takako Negishi-Koga
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Noriko Komatsu
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Asuka Terashima
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Shinichiro Sawa
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Takeshi Nitta
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
| | - Hiroshi Takayanagi
- Department of Osteoimmunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cell Signaling, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Tokyo, Japan; Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology (AMED-CREST), Tokyo, Japan
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11
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Börjesson AE, Farman HH, Movérare-Skrtic S, Engdahl C, Antal MC, Koskela A, Tuukkanen J, Carlsten H, Krust A, Chambon P, Sjögren K, Lagerquist MK, Windahl SH, Ohlsson C. SERMs have substance-specific effects on bone, and these effects are mediated via ERαAF-1 in female mice. Am J Physiol Endocrinol Metab 2016; 310:E912-8. [PMID: 27048997 PMCID: PMC4935145 DOI: 10.1152/ajpendo.00488.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 04/01/2016] [Indexed: 11/22/2022]
Abstract
The bone-sparing effect of estrogens is mediated primarily via estrogen receptor (ER)α, which stimulates gene transcription through activation function (AF)-1 and AF-2. The role of ERαAF-1 for the estradiol (E2) effects is tissue specific. The selective ER modulators (SERMs) raloxifene (Ral), lasofoxifene (Las), and bazedoxifene (Bza) can be used to treat postmenopausal osteoporosis. They all reduce the risk for vertebral fractures, whereas Las and partly Bza, but not Ral, reduce the risk for nonvertebral fractures. Here, we have compared the tissue specificity of Ral, Las, and Bza and evaluated the role of ERαAF-1 for the effects of these SERMs, with an emphasis on bone parameters. We treated ovariectomized (OVX) wild-type (WT) mice and OVX mice lacking ERαAF-1 (ERαAF-1(0)) with E2, Ral, Las, or Bza. All three SERMs increased trabecular bone mass in the axial skeleton. In the appendicular skeleton, only Las increased the trabecular bone volume/tissue volume and trabecular number, whereas both Ral and Las increased the cortical bone thickness and strength. However, Ral also increased cortical porosity. The three SERMs had only a minor effect on uterine weight. Notably, all evaluated effects of these SERMs were absent in ovx ERαAF-1(0) mice. In conclusion, all SERMs had similar effects on axial bone mass. However, the SERMs had slightly different effects on the appendicular skeleton since only Las increased the trabecular bone mass and only Ral increased the cortical porosity. Importantly, all SERM effects require a functional ERαAF-1 in female mice. These results could lead to development of more specific treatments for osteoporosis.
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Affiliation(s)
- Anna E Börjesson
- Rheumatology and Bone Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, United Kingdom
| | - Helen H Farman
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sofia Movérare-Skrtic
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Cecilia Engdahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Maria Cristina Antal
- Strasbourg University, Faculté de Médecine, Institut d'Histologie, Strasbourg, France
| | - Antti Koskela
- Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - Juha Tuukkanen
- Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - Hans Carlsten
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andrée Krust
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (Centre National de la Recherche Scientifique UMR7104; National de la Sante et de la Recherche Medicale U596; ULP, Collège de France), Illkirch, Strasbourg, France
| | - Pierre Chambon
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (Centre National de la Recherche Scientifique UMR7104; National de la Sante et de la Recherche Medicale U596; ULP, Collège de France), Illkirch, Strasbourg, France
| | - Klara Sjögren
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Marie K Lagerquist
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sara H Windahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
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12
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Lin Y, Zhang Y, Huang Y, Wang W, Feng E, Lin Y. Is Bone Mineral Density Associated with Estrogen Receptor a in Chinese Men? A Pilot Study. J HARD TISSUE BIOL 2016. [DOI: 10.2485/jhtb.25.288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Yu Lin
- Joint Surgery Department, the Second Hospital of Fuzhou Affiliated to Xiamen University
| | - Yiyuan Zhang
- Joint Surgery Department, the Second Hospital of Fuzhou Affiliated to Xiamen University
| | - Yunmei Huang
- Fujian Academy of Integrative Medicine (Fujian University of Traditional Chinese Medicine)
| | - Wulian Wang
- Joint Surgery Department, the Second Hospital of Fuzhou Affiliated to Xiamen University
| | - Eryou Feng
- Joint Surgery Department, the Second Hospital of Fuzhou Affiliated to Xiamen University
| | - Yanping Lin
- Fujian Academy of Integrative Medicine (Fujian University of Traditional Chinese Medicine)
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13
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Shi C, Wu J, Yan Q, Wang R, Miao D. Bone marrow ablation demonstrates that estrogen plays an important role in osteogenesis and bone turnover via an antioxidative mechanism. Bone 2015; 79:94-104. [PMID: 26036172 DOI: 10.1016/j.bone.2015.05.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 03/14/2015] [Accepted: 05/26/2015] [Indexed: 01/11/2023]
Abstract
To assess the effect of estrogen deficiency on osteogenesis and bone turnover in vivo, 8-week-old mice were sham-operated or bilaterally ovariectomized (OVX), and after 8 weeks, mechanical bone marrow ablation (BMX) was performed and newly formed bone tissue was analyzed from 6 days to 2 weeks after BMX. Our results demonstrated that OVX mice following BMX displayed 2 reversed phase changes, one phase observed at 6 and 8 days after BMX delayed osteogenesis accompanied by a delay in osteoclastogenesis, and the other phase observed at 12 and 14 days after BMX increased osteoblastic activity and osteoclastic activity. Furthermore, we asked whether impaired osteogenesis caused by estrogen deficiency was associated with increased oxidative stress, and oxidative stress parameters were examined in bone tissue from sham-operated and OVX mice and OVX mice were administrated with antioxidant N-acetyl-l-cysteine (NAC) or vehicle after BMX. Results demonstrated that estrogen deficiency induced oxidative stress in mouse bone tissue with reduced antioxidase levels and activity, whereas NAC administration almost rescued the abnormalities in osteogenesis and bone turnover caused by OVX. Results from this study indicate that estrogen deficiency resulted in primarily impaired osteogenesis and subsequently accelerated bone turnover by increasing oxidative stress and oxidative stress promises to be an effective target in the process of treatment of postmenopausal osteoporosis.
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Affiliation(s)
- Chunmin Shi
- The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Jun Wu
- The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Quanquan Yan
- The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Rong Wang
- The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Dengshun Miao
- The State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China.
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14
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Lin L, Yee SW, Kim RB, Giacomini KM. SLC transporters as therapeutic targets: emerging opportunities. Nat Rev Drug Discov 2015; 14:543-60. [PMID: 26111766 DOI: 10.1038/nrd4626] [Citation(s) in RCA: 497] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carrier (SLC) transporters - a family of more than 300 membrane-bound proteins that facilitate the transport of a wide array of substrates across biological membranes - have important roles in physiological processes ranging from the cellular uptake of nutrients to the absorption of drugs and other xenobiotics. Several classes of marketed drugs target well-known SLC transporters, such as neurotransmitter transporters, and human genetic studies have provided powerful insight into the roles of more-recently characterized SLC transporters in both rare and common diseases, indicating a wealth of new therapeutic opportunities. This Review summarizes knowledge on the roles of SLC transporters in human disease, describes strategies to target such transporters, and highlights current and investigational drugs that modulate SLC transporters, as well as promising drug targets.
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Affiliation(s)
- Lawrence Lin
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA
| | - Sook Wah Yee
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA
| | - Richard B Kim
- Division of Clinical Pharmacology, Department of Medicine, University of Western Ontario, London Health Science Centre, London, Ontario N6A 5A5, Canada
| | - Kathleen M Giacomini
- 1] Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA. [2] Institute for Human Genetics, University of California San Francisco, San Francisco, California 94158, USA
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15
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Vanderschueren D, Laurent MR, Claessens F, Gielen E, Lagerquist MK, Vandenput L, Börjesson AE, Ohlsson C. Sex steroid actions in male bone. Endocr Rev 2014; 35:906-60. [PMID: 25202834 PMCID: PMC4234776 DOI: 10.1210/er.2014-1024] [Citation(s) in RCA: 184] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.
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Affiliation(s)
- Dirk Vanderschueren
- Clinical and Experimental Endocrinology (D.V.) and Gerontology and Geriatrics (M.R.L., E.G.), Department of Clinical and Experimental Medicine; Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine (M.R.L., F.C.); and Centre for Metabolic Bone Diseases (D.V., M.R.L., E.G.), KU Leuven, B-3000 Leuven, Belgium; and Center for Bone and Arthritis Research (M.K.L., L.V., A.E.B., C.O.), Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
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16
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Henning P, Ohlsson C, Engdahl C, Farman H, Windahl SH, Carlsten H, Lagerquist MK. The effect of estrogen on bone requires ERα in nonhematopoietic cells but is enhanced by ERα in hematopoietic cells. Am J Physiol Endocrinol Metab 2014; 307:E589-95. [PMID: 25117411 PMCID: PMC4187026 DOI: 10.1152/ajpendo.00255.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The effects of estrogen on bone are mediated mainly via estrogen receptor (ER)α. ERα in osteoclasts (hematopoietic origin) is involved in the trabecular bone-sparing effects of estrogen, but conflicting data are reported on the role of ERα in osteoblast lineage cells (nonhematopoietic origin) for bone metabolism. Because Cre-mediated cell-specific gene inactivation used in previous studies might be confounded by nonspecific and/or incomplete cell-specific ERα deletion, we herein used an alternative approach to determine the relative importance of ERα in hematopoietic (HC) and nonhematopoietic cells (NHC) for bone mass. Chimeric mice with selective inactivation of ERα in HC or NHC were created by bone marrow transplantations of wild-type (WT) and ERα-knockout (ERα(-/-)) mice. Estradiol treatment increased both trabecular and cortical bone mass in ovariectomized WT/WT (defined as recipient/donor) and WT/ERα(-/-) mice but not in ERα(-/-)/WT or ERα(-/-)/ERα(-/-) mice. However, estradiol effects on both bone compartments were reduced (∼50%) in WT/ERα(-/-) mice compared with WT/WT mice. The effects of estradiol on fat mass and B lymphopoiesis required ERα specifically in NHC and HC, respectively. In conclusion, ERα in NHC is required for the effects of estrogen on both trabecular and cortical bone, but these effects are enhanced by ERα in HC.
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Affiliation(s)
| | | | | | | | | | - Hans Carlsten
- Centre for Bone and Arthritis Research, Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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