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Asmussen NC, Alam S, Lin Z, Cohen DJ, Schwartz Z, Boyan BD. 1α,25-Dihydroxyvitamin D 3 Regulates microRNA Packaging in Extracellular Matrix Vesicles and Their Release in the Matrix. Calcif Tissue Int 2023; 112:493-511. [PMID: 36840756 DOI: 10.1007/s00223-023-01067-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 01/30/2023] [Indexed: 02/26/2023]
Abstract
Growth plate chondrocytes are regulated by numerous factors and hormones as they mature during endochondral bone formation, including transforming growth factor beta-1 (TGFb1), bone morphogenetic protein 2 (BMP2), insulin-like growth factor-1 (IFG1), parathyroid hormone and parathyroid hormone related peptide (PTH, PTHrP), and Indian hedgehog (IHH). Chondrocytes in the growth plate's growth zone (GC) produce and export matrix vesicles (MVs) under the regulation of 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3]. 1α,25(OH)2D3 regulates MV enzyme composition genomically and 1α,25(OH)2D3 secreted by the cells acts on the MV membrane nongenomically, destabilizing it and releasing MV enzymes. This study examined the regulatory role 1α,25(OH)2D3 has over production and packaging of microRNA (miRNA) into MVs by GC cells and the release of miRNA by direct action on MVs. Costochondral cartilage GC cells were treated with 1α,25(OH)2D3 and the miRNA in the cells and MVs sequenced. We also treated MVs with 1α,25(OH)2D3 and determined if the miRNA was released. To assess whether MVs can act directly with chondrocytes and if this is regulated by 1α,25(OH)2D3, we stained MVs with a membrane dye and treated GC cells with them. 1α,25(OH)2D3 regulated production and packaging of a unique population of miRNA into MVs compared to the vehicle control population. 1α,25(OH)2D3 treatment of MVs did not release miRNA. Stained MVs were endocytosed by GC cells and this was increased with 1α,25(OH)2D3 treatment. This study adds new regulatory roles for 1α,25(OH)2D3 with respect to packaging and transport of MV miRNAs.
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Affiliation(s)
- Niels C Asmussen
- School of Integrative Life Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Sheikh Alam
- School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Zhao Lin
- School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - David J Cohen
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Zvi Schwartz
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA
- Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Barbara D Boyan
- College of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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Robinson JL, Soria P, Xu M, Vrana M, Luchetti J, Lu HH, Chen J, Wadhwa S. Estrogen Promotes Mandibular Condylar Fibrocartilage Chondrogenesis and Inhibits Degeneration via Estrogen Receptor Alpha in Female Mice. Sci Rep 2018; 8:8527. [PMID: 29867155 PMCID: PMC5986784 DOI: 10.1038/s41598-018-26937-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 05/18/2018] [Indexed: 12/21/2022] Open
Abstract
Temporomandibular joint degenerative disease (TMJ-DD) is a chronic form of TMJ disorder that specifically afflicts people over the age of 40 and targets women at a higher rate than men. Prevalence of TMJ-DD in this population suggests that estrogen loss plays a role in the disease pathogenesis. Thus, the goal of the present study was to determine the role of estrogen on chondrogenesis and homeostasis via estrogen receptor alpha (ERα) during growth and maturity of the joint. Young and mature WT and ERαKO female mice were subjected to ovariectomy procedures and then given placebo or estradiol treatment. The effect of estrogen via ERα on fibrocartilage morphology, matrix production, and protease activity was assessed. In the young mice, estrogen via ERα promoted mandibular condylar fibrocartilage chondrogenesis partly by inhibiting the canonical Wnt signaling pathway through upregulation of sclerostin (Sost). In the mature mice, protease activity was partly inhibited with estrogen treatment via the upregulation and activity of protease inhibitor 15 (Pi15) and alpha-2-macroglobulin (A2m). The results from this work provide a mechanistic understanding of estradiol on TMJ growth and homeostasis and can be utilized for development of therapeutic targets to promote regeneration and inhibit degeneration of the mandibular condylar fibrocartilage.
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Affiliation(s)
- Jennifer L Robinson
- Columbia University College of Dental Medicine, 622 West 168th Street, New York, NY, 10032, USA. .,Columbia University Department of Biomedical Engineering, 351 Engineering Terrace, 1210 Amsterdam Avenue, New York, NY, 10027, USA.
| | - Paola Soria
- Columbia University Division of Orthodontics, 622 West 168th Street, New York, NY, 10032, USA
| | - Manshan Xu
- Columbia University Division of Orthodontics, 622 West 168th Street, New York, NY, 10032, USA
| | - Mark Vrana
- Columbia University College of Dental Medicine, 622 West 168th Street, New York, NY, 10032, USA
| | - Jeffrey Luchetti
- Columbia University College of Dental Medicine, 622 West 168th Street, New York, NY, 10032, USA
| | - Helen H Lu
- Columbia University Department of Biomedical Engineering, 351 Engineering Terrace, 1210 Amsterdam Avenue, New York, NY, 10027, USA
| | - Jing Chen
- Columbia University Division of Orthodontics, 622 West 168th Street, New York, NY, 10032, USA
| | - Sunil Wadhwa
- Columbia University Division of Orthodontics, 622 West 168th Street, New York, NY, 10032, USA
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Zanatta AP, Brouard V, Gautier C, Goncalves R, Bouraïma-Lelong H, Mena Barreto Silva FR, Delalande C. Interactions between oestrogen and 1α,25(OH) 2-vitamin D 3 signalling and their roles in spermatogenesis and spermatozoa functions. Basic Clin Androl 2017; 27:10. [PMID: 28491323 PMCID: PMC5421336 DOI: 10.1186/s12610-017-0053-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 03/16/2017] [Indexed: 02/07/2023] Open
Abstract
Oestrogens and 1α,25(OH)2-vitamin D3 (1,25-D3) are steroids that can provide effects by binding to their receptors localised in the cytoplasm and in the nucleus or the plasma membrane respectively inducing genomic and non-genomic effects. As confirmed notably by invalidation of the genes, coding for their receptors as tested with mice with in vivo and in vitro treatments, oestrogens and 1,25-D3 are regulators of spermatogenesis. Moreover, some functions of ejaculated spermatozoa as viability, DNA integrity, motility, capacitation, acrosome reaction and fertilizing ability are targets for these hormones. The studies conducted on their mechanisms of action, even though not completely elicited, have allowed the demonstration of putative interactions between their signalling pathways that are worth examining more closely. The present review focuses on the elements regulated by oestrogens and 1,25-D3 in the testis and spermatozoa as well as the interactions between the signalling pathways of both hormones.
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Affiliation(s)
- Ana Paula Zanatta
- INRA, OeReCa, Normandie University, UNICAEN, 14000 Caen, France.,Biochemistry Department, Laboratory of Hormones & Signal Transduction, UFSC, Florianópolis, Brazil
| | - Vanessa Brouard
- INRA, OeReCa, Normandie University, UNICAEN, 14000 Caen, France
| | - Camille Gautier
- INRA, OeReCa, Normandie University, UNICAEN, 14000 Caen, France
| | - Renata Goncalves
- INRA, OeReCa, Normandie University, UNICAEN, 14000 Caen, France.,Biochemistry Department, Laboratory of Hormones & Signal Transduction, UFSC, Florianópolis, Brazil
| | | | | | - Christelle Delalande
- INRA, OeReCa, Normandie University, UNICAEN, 14000 Caen, France.,Laboratoire Œstrogènes, Reproduction, Cancer (OeReCa), EA 2608 USC INRA1377, Université de Caen Normandie, Esplanade de la Paix, CS 14032, 14032 CAEN cedex 5, France
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Pan Q, O'Connor MI, Coutts RD, Hyzy SL, Olivares-Navarrete R, Schwartz Z, Boyan BD. Characterization of osteoarthritic human knees indicates potential sex differences. Biol Sex Differ 2016; 7:27. [PMID: 27257472 PMCID: PMC4890516 DOI: 10.1186/s13293-016-0080-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/12/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The prevalence of osteoarthritis is higher in women than in men in every age group, and overall prevalence increases with advancing age. Sex-specific differences in the properties of osteoarthritic joint tissues may permit the development of sex-specific therapies. Sex hormones regulate cartilage and bone development and homeostasis in a sex-dependent manner. Recent in vitro studies show that the vitamin D3 metabolite 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] also has sex-specific effects on musculoskeletal cells, suggesting that vitamin D3 metabolites may play a role in osteoarthritis-related sex-specific differences. The purpose of this study was to determine if sex-specific differences exist in synovial fluid and knee tissues isolated from male and female patients with severe knee osteoarthritis. We determined the presence of vitamin D3 metabolites, inflammatory cytokines, growth factors, and matrix metalloproteinases (MMPs) in synovial fluid and assessed responses of articular chondrocytes and subchondral osteoblasts to 17β-estradiol, dihydrotestosterone, and 1α,25(OH)2D3. METHODS Samples from knee joints of 10 Caucasian male and 10 Caucasian female patients with advanced osteoarthritis aged 65 to 75 years were obtained from total knee arthroplasty. Vitamin D metabolites, cytokines, MMPs, and growth factors in the synovial fluid were measured. Primary cultures of chondrocytes were isolated from fibrillated articular cartilage adjacent to osteoarthritis lesions and minimally affected cartilage distal to the lesion. Osteoblasts were isolated from the subchondral bone. Expression of receptors for 17β-estradiol and 1α,25(OH)2D3 was assessed by real-time PCR. Chondrocytes and osteoblasts were treated with 10(-8) M 17β-estradiol, dihydrotestosterone, or 1α,25(OH)2D3 and effects on gene expression and protein synthesis determined. RESULTS Histology of the articular cartilage confirmed advanced osteoarthritis. Sex differences were found in synovial fluid levels of vitamin D metabolites, cytokines, and metalloproteinases as well as in the cellular expression of receptors for 17β-estradiol and 1α,25(OH)2D3. Male cells were more responsive to 1α,25(OH)2D3 and dihydrotestosterone, whereas 17β-estradiol-affected female cells. CONCLUSIONS These results demonstrate that there are underlying sex differences in knee tissues affected by osteoarthritis. Our findings do not address osteoarthritis etiology but have implications for different prevention methods and treatments for men and women. Further research is needed to better understand these sex-based differences.
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Affiliation(s)
- Qingfen Pan
- Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA USA
| | - Mary I O'Connor
- Center for Musculoskeletal Care, Yale University School of Medicine, New Haven, CT USA
| | - Richard D Coutts
- Department of Orthopaedics, University of California at San Diego, San Diego, CA USA
| | - Sharon L Hyzy
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA
| | | | - Zvi Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA ; Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX USA
| | - Barbara D Boyan
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA ; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA USA ; School of Engineering, Virginia Commonwealth University, 601 West Main Street, Suite 331, Richmond, VA 23284 USA
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Villalvilla A, Gomez R, Lugo L, Lopez-Oliva F, Largo R, Herrero-Beaumont G. Aromatase expression in human chondrocytes: An induction due to culture. Maturitas 2015; 85:27-33. [PMID: 26857876 DOI: 10.1016/j.maturitas.2015.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/03/2015] [Accepted: 12/02/2015] [Indexed: 12/01/2022]
Abstract
OBJECTIVES Despite the high prevalence of osteoarthritis (OA) in postmenopausal women, a relationship between circulating estrogen levels and the development of OA has not been found. Therefore, the purpose of this study was to evaluate the expression and activity of aromatase, a key enzyme in local production of estrogens, in human OA cultured articular chondrocytes, and to determine the physiological relevance of this enzyme in cartilage. METHODS Human OA articular chondrocytes were isolated and cultured. Local production of estradiol was measured after incubation with 100 ng/ml testosterone for 8 and 24h. Furthermore, chondrocytes were culture for 2h, 48 h, 7 days or 15 days, or in alginate beads for 10 days. Aromatase, type II and X collagen, aggrecan, alkaline phosphatase, and Runx2 expression were evaluated in cartilage, freshly isolated chondrocytes and cultured chondrocytes. RESULTS Aromatase was expressed and active in cultured human chondrocytes. Human cartilage, freshly isolated chondrocytes, and chondrocytes cultured for 2h expressed an insignificant amount of aromatase; however, expression arose after 48 h of culture and remained increased thereafter. Aromatase expression was not related to estrogen deprivation and was inversely correlated with differentiation. Re-differentiation did not reduce its expression. CONCLUSIONS Aromatase presents an almost undetectable expression in human cartilage but is induced in cultured chondrocytes. Therefore, human cartilage might act as a mere target for estrogens rather than a producer, and researchers using cell expansion in culture for latter therapies should consider these changes in estrogen metabolism which may not be reverted after re-differentiation.
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Affiliation(s)
- Amanda Villalvilla
- Bone and Joint Research Unit, IIS Fundación Jiménez Díaz, Madrid 28040, Spain.
| | - Rodolfo Gomez
- Bone and Joint Research Unit, IIS Fundación Jiménez Díaz, Madrid 28040, Spain; Musculoskeletal Pathology Lab, Institute IDIS, Santiago de Compostela, 15706, Spain.
| | - Laura Lugo
- Bone and Joint Research Unit, IIS Fundación Jiménez Díaz, Madrid 28040, Spain.
| | - Felipe Lopez-Oliva
- Department of Orthopedic Surgery, IIS Fundación Jiménez Díaz, Madrid 28040, Spain.
| | - Raquel Largo
- Bone and Joint Research Unit, IIS Fundación Jiménez Díaz, Madrid 28040, Spain.
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Rochira V, Kara E, Carani C. The endocrine role of estrogens on human male skeleton. Int J Endocrinol 2015; 2015:165215. [PMID: 25873947 PMCID: PMC4383300 DOI: 10.1155/2015/165215] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 11/14/2014] [Indexed: 12/31/2022] Open
Abstract
Before the characterization of human and animal models of estrogen deficiency, estrogen action was confined in the context of the female bone. These interesting models uncovered a wide spectrum of unexpected estrogen actions on bone in males, allowing the formulation of an estrogen-centric theory useful to explain how sex steroids act on bone in men. Most of the principal physiological events that take place in the developing and mature male bone are now considered to be under the control of estrogen. Estrogen determines the acceleration of bone elongation at puberty, epiphyseal closure, harmonic skeletal proportions, the achievement of peak bone mass, and the maintenance of bone mass. Furthermore, it seems to crosstalk with androgen even in the determination of bone size, a more androgen-dependent phenomenon. At puberty, epiphyseal closure and growth arrest occur when a critical number of estrogens is reached. The same mechanism based on a critical threshold of serum estradiol seems to operate in men during adulthood for bone mass maintenance via the modulation of bone formation and resorption in men. This threshold should be better identified in-between the ranges of 15 and 25 pg/mL. Future basic and clinical research will optimize strategies for the management of bone diseases related to estrogen deficiency in men.
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Affiliation(s)
- Vincenzo Rochira
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via P. Giardini 1355, 41126 Modena, Italy
- Azienda USL di Modena, Nuovo Ospedale Civile Sant'Agostino Estense (NOCSAE), Via P. Giardini 1355, 41126 Modena, Italy
- *Vincenzo Rochira:
| | - Elda Kara
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via P. Giardini 1355, 41126 Modena, Italy
| | - Cesare Carani
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via P. Giardini 1355, 41126 Modena, Italy
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Boyan BD, Hart DA, Enoka RM, Nicolella DP, Resnick E, Berkley KJ, Sluka KA, Kwoh CK, Tosi LL, O'Connor MI, Coutts RD, Kohrt WM. Hormonal modulation of connective tissue homeostasis and sex differences in risk for osteoarthritis of the knee. Biol Sex Differ 2013; 4:3. [PMID: 23374322 PMCID: PMC3583799 DOI: 10.1186/2042-6410-4-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 12/10/2012] [Indexed: 12/24/2022] Open
Abstract
Young female athletes experience a higher incidence of ligament injuries than their male counterparts, females experience a higher incidence of joint hypermobility syndrome (a risk factor for osteoarthritis development), and post-menopausal females experience a higher prevalence of osteoarthritis than age-matched males. These observations indicate that fluctuating sex hormone levels in young females and loss of ovarian sex hormone production due to menopause likely contribute to observed sex differences in knee joint function and risk for loss of function. In studies of osteoarthritis, however, there is a general lack of appreciation for the heterogeneity of hormonal control in both women and men. Progress in this field is limited by the relatively few preclinical osteoarthritis models, and that most of the work with established models uses only male animals. To elucidate sex differences in osteoarthritis, it is important to examine sex hormone mechanisms in cells from knee tissues and the sexual dimorphism in the role of inflammation at the cell, tissue, and organ levels. There is a need to determine if the risk for loss of knee function and integrity in females is restricted to only the knee or if sex-specific changes in other tissues play a role. This paper discusses these gaps in knowledge and suggests remedies.
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Affiliation(s)
- Barbara D Boyan
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, GA 30332-0363, USA
| | - David A Hart
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Roger M Enoka
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Daniel P Nicolella
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Eileen Resnick
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Karen J Berkley
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Kathleen A Sluka
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - C Kent Kwoh
- University of Pittsburgh and Pittsburgh VA Healthcare System, Pittsburgh, PA, USA.,Epidemiology, and Clinical and Translational Science Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, University of Pittsburgh Arthritis Institute, Pittsburgh, USA
| | - Laura L Tosi
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Mary I O'Connor
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA.,Mayo Clinic, 4500 San Pablo Road, Jacksonville, Florida, USA
| | - Richard D Coutts
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
| | - Wendy M Kohrt
- Isis Research Network on Musculoskeletal Health, Society for Women's Health Research, 1025 Connecticut Avenue, NW Suite 601, Washington, DC, 20036, USA
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Colombini A, Lanteri P, Lombardi G, Grasso D, Recordati C, Lovi A, Banfi G, Bassani R, Brayda-Bruno M. Metabolic effects of vitamin D active metabolites in monolayer and micromass cultures of nucleus pulposus and annulus fibrosus cells isolated from human intervertebral disc. Int J Biochem Cell Biol 2012; 44:1019-30. [PMID: 22481027 DOI: 10.1016/j.biocel.2012.03.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 03/21/2012] [Indexed: 11/30/2022]
Abstract
Intragenic polymorphisms in the vitamin D receptor gene are linked to disc degeneration features, suggesting that alterations in the vitamer-mediated signalling could be involved in the pathophysiology of the disc and that interaction of disc cells with vitamin D metabolites may be critical for disc health. The vitamer-mediated modulation of disc cells proliferation, metabolic activity, extracellular matrix (ECM) genes expression and proteins production was investigated. It was stated that disc cells express vitamin D receptor and are very sensitive to metabolic stimuli. In monolayer cultures, 1,25(OH)(2)D(3), but not 24,25(OH)(2)D(3), determined an inhibition of the proliferation and regulated also the ECM genes expression in nucleus pulposus and annulus fibrosus cells. Micromass cultures induced a more physiologic expression pattern of extracellular matrix genes. Cells Treatment with vitamin D metabolites did not result in relevant modifications of glycosaminoglycans production, except for annulus cells, whose production was reduced after 1,25(OH)(2)D(3) treatment. Moreover, a reduced glycosaminoglycans staining in both cell types and a significant reduced aggrecan gene expression in annulus cells treated with 1,25(OH)(2)D(3) were observed. A reduction of collagen I and II staining in annulus cells 1,25(OH)(2)D(3) treated, in accordance with a downregulation of collagen genes expression, was also registered. Finally, the vitamin D receptor gene expression did not show significant metabolite-mediated modification in monolayer or micromass cultures. These findings could enhance new insights on the biochemical mechanisms regulated by vitamin D in disc cartilage and possibly involved in the development of physiological/pathological modifications of the disc.
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Affiliation(s)
- Alessandra Colombini
- I.R.C.C.S. Istituto Ortopedico Galeazzi, Via R. Galeazzi 4, 20161 Milano, Italy.
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9
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Impact of sex hormones, insulin, growth factors and peptides on cartilage health and disease. ACTA ACUST UNITED AC 2011; 45:239-93. [DOI: 10.1016/j.proghi.2010.11.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2010] [Indexed: 12/27/2022]
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10
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Karimian E, Chagin AS, Sävendahl L. Genetic regulation of the growth plate. Front Endocrinol (Lausanne) 2011; 2:113. [PMID: 22654844 PMCID: PMC3356134 DOI: 10.3389/fendo.2011.00113] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 12/20/2011] [Indexed: 12/12/2022] Open
Abstract
The epiphyseal growth plate consists of a layer of cartilage present only during the growth period and vanishes soon after puberty in long bones. It is divided to three well-defined zones, from epiphyses; resting, proliferative, and hypertrophic zones. Chondrocyte proliferation and differentiation and subsequent bone formation in this cartilage are controlled by various endocrine, autocrine, and paracrine factors which finally results into elimination of the cartilaginous tissue and promotion of the epiphyseal fusion. As chondrocytes differentiate from round, quiescent, and single structure to flatten and proliferative and then large and terminally differentiated, they experience changes in their gene expression pattern which allow them to transform from cartilaginous tissue to bone. This review summarizes the literature in this area and shortly describes different factors that affect growth plate cartilage both at the local and systemic levels. This may eventually help us to develop new treatment strategies of different growth disorders.
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Affiliation(s)
- Elham Karimian
- Pediatric Endocrinology Unit, Department of Women’s and Children’s Health, Karolinska InstitutetStockholm, Sweden
- *Correspondence: Elham Karimian, Pediatric Endocrinology Unit Q2:08, Karolinska University Hospital, 171 76 Stockholm, Sweden. e-mail:
| | - Andrei S. Chagin
- Pediatric Endocrinology Unit, Department of Women’s and Children’s Health, Karolinska InstitutetStockholm, Sweden
| | - Lars Sävendahl
- Pediatric Endocrinology Unit, Department of Women’s and Children’s Health, Karolinska InstitutetStockholm, Sweden
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11
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Bairey Merz CN, Mark S, Boyan BD, Jacobs AK, Shah PK, Shaw LJ, Taylor D, Marbán E. Proceedings from the scientific symposium: Sex differences in cardiovascular disease and implications for therapies. J Womens Health (Larchmt) 2010; 19:1059-72. [PMID: 20500123 PMCID: PMC2940456 DOI: 10.1089/jwh.2009.1695] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED A consortium of investigator-thought leaders was convened at the Heart Institute at Cedars-Sinai Medical Center and produced the following summary points: POINT 1: Important sex differences exist in cardiovascular disease (CVD) that affect disease initiation, diagnosis, and treatment. IMPLICATION Research that acknowledges these differences is needed to optimize outcomes in women and men. POINT 2: Atherosclerosis is qualitatively and quantitatively different in women and men; women demonstrate more plaque erosion and more diffuse plaque with less focal artery lumen intrusion. IMPLICATION Evaluation of CVD strategies that include devices should be used to explore differing anatomical shapes and surfaces as well as differing drug coating and eluting strategies. POINT 3: Bone marrow progenitor cells (PCs) engraft differently based on the sex of the donor cell and the sex of the recipient. IMPLICATION PC therapeutic studies need to consider the sex of cells of the source and the recipient. POINT 4: Women have a greater risk of venous but not arterial thrombosis compared with men, as well as more bleeding complications related to anticoagulant treatment. Several genes coding for proteins involved in hemostasis are regulated by sex hormones. IMPLICATIONS Research should be aimed at evaluation of sex-based differences in response to anticoagulation based on genotype. POINT 5: Women and men can have differences in pharmacological response. IMPLICATION Sex-specific pharmacogenomic studies should be included in pharmacological development. POINT 6: CVD progression results from an imbalance of cell injury and repair in part due to insufficient PC repair, which is affected by sex differences, where females have higher circulating levels of PCs with greater rates of tissue repair. IMPLICATION CVD regenerative strategies should be directed at learning to deliver cells that shift the recipient balance from injury toward repair. CVD repair strategies should ideally be tested first in females to have the best chance of success for proof-of-concept.
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Affiliation(s)
- C Noel Bairey Merz
- Women's Heart Center, Cedars-Sinai Heart Institute, 444 S. San Vincente Boulevard, Los Angeles, CA 90048, USA.
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12
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Li F, Yu S, Feng X, Wang H, Fu S, Ding Y. Locally synthesized estrogen: A novel target in the development of OA. Med Hypotheses 2009; 73:144-6. [DOI: 10.1016/j.mehy.2009.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 02/25/2009] [Accepted: 03/01/2009] [Indexed: 10/20/2022]
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Yu S, Xing X, Liang S, Ma Z, Li F, Wang M, Li Y. Locally synthesized estrogen plays an important role in the development of TMD. Med Hypotheses 2009; 72:720-2. [DOI: 10.1016/j.mehy.2008.11.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 12/04/2008] [Accepted: 11/19/2008] [Indexed: 11/28/2022]
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Yu SB, Wang MQ, Li YQ, Lv X, Jiang Y, Dong GY, Ma ZF. The effects of age and sex on the expression of oestrogen and its receptors in rat mandibular condylar cartilages. Arch Oral Biol 2009; 54:479-85. [PMID: 19264293 DOI: 10.1016/j.archoralbio.2009.01.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 01/21/2009] [Accepted: 01/25/2009] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Oestrogen expression may indicate a difference in resistance potential to mechanical strain. The purpose of this study was to investigate the expression of oestrogen and oestrogen receptors in mandibular condylar cartilages in male and female Sprague-Dawley rats at different ages. MATERIALS AND METHODS One-hundred SD rats at the age of 2, 4, 8 weeks and 4, 12 months in both sexes, 10 in each age-sex group, were enrolled in this study. The expression of oestradiol, ERalpha and ERbeta was detected in mandibular condylar cartilages by the method of immunohistochemistry, and enzyme-linked immunosorbent assay or western blot. RESULTS Oestradiol and ERs immunoreactivity were obvious in mandibular condylar cartilages of SD rats. Oestradiol and ERalpha were observed in hypertrophic and mature layers, while ERbeta only in hypertrophic layer. There was no sex difference of same age (except 8-week age group) in the expression of oestradiol. The expression of both ERs, however, was usually higher in male than in age-matched female rats (P<0.05), except that the 8-week-old female rats showed a higher ERalpha expression and the 4- and 8-week-old female rats showed a higher ERbeta expression than the age-matched male ones in western blot results (P<0.05). CONCLUSIONS The results that oestradiol, ERalpha and ERbeta are co-expressed in rat mandibular condylar cartilage, indicate that mandibular condylar cartilage is a target for oestrogen. The age and sex related differences in ERs expression may indicate a difference in potential to resist mechanical loading between genders at different ages.
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Affiliation(s)
- Shi-Bin Yu
- Department of Oral Anatomy and Physiology and TMD, School of Stomatology, The Fourth Military Medical University, Xi'an, China
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1,25(OH)2-vitamin D3 inhibits proliferation and decreases production of monocyte chemoattractant protein-1, thrombopoietin, VEGF, and angiogenin by human annulus cells in vitro. Spine (Phila Pa 1976) 2008; 33:755-65. [PMID: 18379402 DOI: 10.1097/brs.0b013e3181695d59] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Human lumbar anulus tissue and cultured human lumbar anulus cells were used in retrospective studies of the immunocytochemical localization of the vitamin D receptor (VDR) in disc tissue, and of the in vitro effects of the active metabolite of vitamin D, 1,25(OH)2D3, on anulus cell proliferation, cytokine, and proteoglycan (PG) production. 24,25-D3 was also analyzed. Studies were approved by the authors' Human Subjects Institutional Review Board. Discs were obtained from surgical specimens and from control donors. OBJECTIVES To determine if human anulus cells express the VDR in vivo, and to test the effect of in vitro exposure to 1,25(OH)2D3 and 24,25-D3 on anulus cell proteoglycan and cytokine production in 3-dimensional culture. SUMMARY OF BACKGROUND DATA Intragenic polymorphisms in the VDR gene have been associated with disc degeneration. 1,25(OH)2D3 has well-recognized effects on calcium homeostasis and bone mineralization, and is a negative growth regulator of a variety of normal and tumor cells. Its effects on human disc cells, however, are unexplored. METHODS Immunocytochemistry was performed on human lumbar disc anulus tissue from 19 subjects; human disc cells were cultured to test the effect of 1,25(OH)2D3 on proliferation of anulus cells from 5 subjects. A paired experimental design was used to determine proteoglycan production in control or 1,25(OH)2D3-treated cells, or in control or 24,25-D3-treated cells using the dimethylmethylene blue assay. A paired experimental design was also used to identify differences in cytokine production in conditioned media from control or 1,25(OH)2D3-treated cells, or in control or 24,25-D3-treated cells using ELISA assays. RESULTS Immunocytochemistry documented expression of the VDR in anulus cells. Young donor discs (aged newborn, 15 years) showed positive localization in all cells of the outer anulus, and some inner anulus cells. In adults (mean age, 38.9 years), some, but not all anulus cells, showed positive localization. Exposure to 10M 1,25(OH)2D3 in monolayer significantly reduced cell proliferation in vitro (P = 0.03). PG production in 3-dimensional was unchanged from control in both 1,25(OH)2D3- and 24,25-D3-treated cells. Cytokine production differed, however. 1,25(OH)2D3-treated cells showed significantly decreased production of vascular endothelial growth factor (VEGF) (P = 0.01), monocyte chemoattractant protein-1 (MCP-1) (P = 0.0006), angiogenin (P = 0.002), and thrombopoietin (P = 0.03) compared with controls. 24,25-D3-treated cells showed significantly elevated vascular endothelial growth factor-D (P = 0.01), beta-fibroblast growth factor (0.03), and significantly decreased interleukin-8, interferon-gamma, leptin, MCP-1, and TIMP-2 (tissue inhibitor of metalloproteinases-2) compared with controls (P <or= 0.01). CONCLUSION Data suggest that 1,25(OH)2D3 and 24,25-D3 may play roles as regulators of cell proliferation and production of specific cytokines in the lumbar anulus.
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Abstract
Longitudinal growth, which is primarily due to chondrocytic activity at the level of the epiphyseal growth plate, is influenced by many hormones and growth factors in an endocrine and paracrine manner. Their influence is even more complex during the accelerated growth period of puberty that accounts for about 20% of final adult height. Although abnormalities of growth during puberty are very common, the underlying mechanisms that govern the beginning and cessation of pubertal growth at the level of the growth plate are poorly understood. Sex steroids play a crucial role in pubertal growth both at the systemic level via the GH/IGF-1 axis and at the local level of the epiphyseal growth plate. In both sexes it is now accepted that oestrogen is the critical hormone in controlling growth plate acceleration and fusion. This paper reviews the mechanisms that influence pubertal growth and the problems that are associated with disorders of gonadal function.
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Affiliation(s)
- R J Perry
- Bone & Endocrine Research Group, Royal Hospital for Sick Children, Glasgow, UK.
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McMillan J, Fatehi-Sedeh S, Sylvia VL, Bingham V, Zhong M, Boyan BD, Schwartz Z. Sex-specific regulation of growth plate chondrocytes by estrogen is via multiple MAP kinase signaling pathways. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:381-92. [PMID: 16713447 DOI: 10.1016/j.bbamcr.2006.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Revised: 02/07/2006] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
Both male and female rat growth plate cartilage cells possess estrogen receptors (ERs), but 17beta-estradiol (E(2)) activates protein kinase C (PKC) and PKC-dependent biological responses to E(2) only in cells from female animals. PKC signaling can elicit genomic responses via mitogen activated protein kinase (MAPK) and E(2) has been shown to activate ERK MAPK in many cells, suggesting that MAPK may play a role in growth plate chondrocytes as well. We tested if E(2) increases MAPK activity and if so, whether the response is limited to female cells, if it is PKC-dependent, and if the mechanism involves traditional ER pathways. We also determined the contribution of MAPK to the biological response of growth plate chondrocytes and assessed the relative contributions of ERK, p38 and JNK MAPKs. Female rat costochondral cartilage cells were treated with E(2) and MAPK-specific activity determined in cell layer lysates. The mechanism of MAPK activation was determined by treating the cells with E(2) conjugated to bovine serum albumin (E(2)-BSA) to assess if membrane receptors were involved; stereospecificity was determined using 17alpha-estradiol; PKC and phospholipase C (PLC) dependence was determined using specific inhibitors; and the ER agonist diethylstilbestrol, the ER antagonist ICI 182780, and tamoxifen were used to assess the role of traditional ER pathways. E(2) regulation of ERK1/2 MAPK was assessed and the relative roles of ERK1/2, p38 and JNK MAPKs determined using specific inhibitors. E(2) caused a rapid dose-dependent activation of MAPK that was greatest in cells treated for 9 min with 10(-9) M hormone; activity remained elevated for 3 h. E(2)'s effect on MAPK was stereospecific and comparable to that of E(2)-BSA. It was insensitive to DES and ICI 182780, dependent on PKC and PLC, blocked by tamoxifen and it did not require gene transcription or translation. E(2) had no effect on ERK1 or ERK2 mRNA or protein but it caused a rapid phosphorylation of ERK1/2 at 9 min. Inhibition of ERK1/2 and p38 MAPK reduced the stimulatory effects of E(2) on alkaline phosphatase activity and [(35)S]-sulfate incorporation. These results suggest that E(2) regulates MAPK through a sex-specific membrane-mediated mechanism that does not involve cytosolic ERs in a traditional sense and that ERK1/2 and p38 mediate the downstream biological effects of the hormone.
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Affiliation(s)
- J McMillan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Drive NW, Atlanta, 30332, USA
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Lu FZ, Kitazawa Y, Hara Y, Jiang JY, Li XK. Long-term gene expression using the lentiviral vector in rat chondrocytes. Clin Orthop Relat Res 2005; 439:243-52. [PMID: 16205166 DOI: 10.1097/00003086-200510000-00041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The optimal approach to a long-term stable transgene expression in chondrocytes has not been established. Recently, lentiviral vectors have been used for transfection of some cultured cell lines. Our study tests the hypothesis that lentiviral vectors lead to longer gene expression in primary chondrocytes. We transfected lentiviral and adenoviral vectors carrying the green fluorescence protein gene to chondrocytes at different infection rates and cultured them in collagen Type I gel for up to 6 weeks. We also transplanted the cells of gel-suspended chondrocytes into the backs of nude mice. The mRNA expression of collagen Type II and aggrecan core protein was tested by real time polymerase chain reaction. The morphologic features and proliferation of chondrocytes were observed. Lentiviral vectors could transfect the green fluorescence protein gene to chondrocytes and the adenoviral vector, and there was no influence on the proliferation and phenotype of the chondrocytes. The percentage of lentiviral green fluorescence protein positive cells was much greater than the adenoviral green fluorescence protein at the end of 6 weeks. Stable green fluorescence protein expression was observed only in the lentivirus-transfected implants. The gene transfected by the lentiviral vector can be expressed efficiently for a long time and may be useful for gene transfer in cartilage defect repair.
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Affiliation(s)
- Fei-Zhou Lu
- Laboratory of Transplantation Immunology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, Japan
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Kinney RC, Schwartz Z, Week K, Lotz MK, Boyan BD. Human articular chondrocytes exhibit sexual dimorphism in their responses to 17beta-estradiol. Osteoarthritis Cartilage 2005; 13:330-7. [PMID: 15780646 DOI: 10.1016/j.joca.2004.12.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2004] [Accepted: 12/11/2004] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The higher incidence of osteoarthritis in females suggests that there may be intrinsic sex-specific differences in human articular chondrocytes. 17beta-Estradiol (E2) regulates rat growth plate chondrocytes through traditional nuclear receptor mechanisms, but only female cells exhibit rapid membrane-associated effects mediated through protein kinase C (PKC) alpha. Here we demonstrate sexual dimorphism in the physiological response of human articular chondrocytes to E2. METHODS Articular chondrocytes were obtained at the time of autopsy from three male and three female donors between 16 and 39 years of age. Second passage cultures were treated with E2 for 24 h to assess the effects of the hormone on [3H]-thymidine incorporation, [35S]-sulfate incorporation, and alkaline phosphatase specific activity. In addition, the chondrocytes were treated for 3, 9, 90 or 270 min and PKC specific activity was determined. RESULTS All chondrocytes were positive for aggrecan and estrogen receptor alpha mRNAs but were negative for type II collagen mRNA. Only cells from female donors responded to E2. DNA synthesis, sulfate incorporation and alkaline phosphatase activity were increased. E2 caused a rapid increase in PKC activity in the female cells within 9 min that was maximal at 90 min. Treatment with the PKC inhibitor chelerythrine blocked these effects. CONCLUSIONS These results provide the first definitive evidence that normal human cells exhibit an intrinsic sex-specific response to E2 and suggest that sexual dimorphism may be an important variable in assessing the pathways that modulate cell behavior.
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Affiliation(s)
- R C Kinney
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Karperien M, van der Eerden BCJ, Wit JM. Genomic and non-genomic actions of sex steroids in the growth plate. Pediatr Nephrol 2005; 20:323-9. [PMID: 15690194 DOI: 10.1007/s00467-004-1710-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Revised: 09/22/2004] [Accepted: 09/24/2004] [Indexed: 11/28/2022]
Abstract
Sex steroids, and particularly estrogens, are important regulators of bone growth and bone mass accrual. For a long time, it was thought that these effects were mainly caused by their modulatory effects on the somatotrophic axis. Data gathered in the past years have challenged this view and it is now widely accepted that many of the effects of sex steroids on growth and bone mass accrual are caused by direct effects on target cells in the growth plate and bone. This review summarizes and discusses some of our latest findings on the expression of sex steroid receptors in the growth plate, the source of the ligands activating these receptors, and their putatitive mechanism of action predominantly focusing on observations in the rat.
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Affiliation(s)
- Marcel Karperien
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
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Raz P, Nasatzky E, Boyan BD, Ornoy A, Schwartz Z. Sexual dimorphism of growth plate prehypertrophic and hypertrophic chondrocytes in response to testosterone requires metabolism to dihydrotestosterone (DHT) by steroid 5-alpha reductase type 1. J Cell Biochem 2005; 95:108-19. [PMID: 15723286 DOI: 10.1002/jcb.20298] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Rat costochondral growth plate chondrocytes exhibit sex-specific and cell maturation dependent responses to testosterone. Only male cells respond to testosterone, although testosterone receptors are present in both male and female cells, suggesting other mechanisms are involved. We examined the hypothesis that the sex-specific response of rat costochondral cartilage cells to testosterone requires further metabolism of the hormone to dihydrotestosterone (DHT). Resting zone (RC) and growth zone (GC, prehypertrophic and upper hypertrophic zones) chondrocytes from male and female Sabra strain rats exhibited sex-specific responses to testosterone and DHT: only male cells were responsive. Testosterone and DHT treatment for 24 h caused a comparable dose-dependent increase in [3H]-thymidine incorporation in quiescent preconfluent cultures of male GC cells, and a comparable increase in alkaline phosphatase specific activity in confluent cultures. RC cells responded in a differential manner to testosterone and DHT. Testosterone decreased DNA synthesis in male RC cells but DHT had no effect and alkaline phosphatase specific activity of male RC cells was unaffected by either hormone. Inhibition of steroid 5alpha-reductase activity with finasteride (1, 5, or 10 microg/ml), reduced the response of male GC cells to testosterone in a dose-dependent manner, indicating that metabolism to DHT was required. RT-PCR showed that both male and female cells expressed mRNAs for steroid 5alpha-reductase type 1 but lacked mRNAs for the type 2 form of the enzyme. Male cells also exhibited 5alpha-reductase activity but activity of this enzyme was undetectable in female cells. These observations show that sex-specific responses of rat growth zone chondrocytes to testosterone requires the further metabolism of the hormone to DHT and that the effect of DHT in the male growth plate is maturation-state dependent. Failure of female chondrocytes to respond to testosterone may reflect differences in testosterone metabolism, since these cells possess greater ability to aromatize the hormone to estradiol.
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Affiliation(s)
- P Raz
- Hebrew University Hadassah, Jerusalem, Israel
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22
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Abstract
Estrogen plays an important role in the human growth plate by accelerating growth and promoting epiphyseal fusion in both sexes. Nevertheless, the precise mechanisms responsible for these effects are poorly understood. In the present study, we examined the role of 17beta-estradiol (E2) on cell proliferation and viability, type X collagen synthesis, alkaline phosphatase activity, and matrix calcification in primary cultures of resting, proliferating, and prehypertrophic chondrocytes derived from explants of the bovine fetal epiphyseal growth plate. Growth plate chondrocytes were isolated and separated into maturationally distinct subpopulations, which were cultured for 7-21 days to high density in either (1) serum-free medium, (2) 1 nM thyroid hormone (T3), (3) E2 concentrations ranging from 10(-13) M to 10(-7) M, or (4) a combination of T3 and E2. To compare E2 effects in both sexes, chondrocytes were harvested from 8 fetuses of both sexes. After hormone treatment, cell cultures were analyzed for cell number and viability, collagen type X, alkaline phosphatase (ALP), and matrix calcification. Neither DNA content nor cell viability were affected by the duration or type of hormone treatment. By itself, E2 stimulated maturation of all subpopulations only in pharmacologic doses (10(-7) M). Physiologic E2 concentrations were no different than negative controls treated with ITS (insulin, transferrin, and selenite). Regardless of E2 concentrations, the addition of E2 to 1 nM T3 did not appreciably affect the response to T3 alone, which stimulates maturation of the phenotype. All effects were comparable in both male and female chondrocytes, in all cell subpopulations (maturation stages) and fetuses of varying gestational age. These findings indicate that at physiologic concentrations, the effects of E2 on fetal bovine growth plate chondrocyte appear to be indirect and independent of T3, suggesting that, in vivo, E2 acts in concert with other factors or hormones to induce fusion of the growth plate.
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Affiliation(s)
- C Rodd
- Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
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