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Dey Bhowmik A, Das T, Chattopadhyay A. Chronic exposure to environmentally relevant concentration of fluoride impairs osteoblast's collagen synthesis and matrix mineralization: Involvement of epigenetic regulation in skeletal fluorosis. ENVIRONMENTAL RESEARCH 2023; 236:116845. [PMID: 37558119 DOI: 10.1016/j.envres.2023.116845] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/30/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023]
Abstract
Globally, 200 million people are suffering from toxic manifestations of Fluoride(F), dental and skeletal fluorosis; unfortunately, there is no treatment. To unravel the pathogenesis of skeletal fluorosis, we established fluorosis mice by treating environmentally relevant concentration of F (15 ppm NaF) through drinking water for 4 months. As in skeletal fluorosis, locomotor disability, crippling deformities occur and thus, our hypothesis was F might adversely affects collagen which gives the bone tensile strength. This work inevitably had to be carried out on osteoblast cells, responsible for synthesis, deposition, and mineralization of bone matrix. Isolated osteoblast cells were confirmed by ALP activity and mineralized nodules formation. Expression of collagen Col1a1, Col1a2, COL1A1 was significantly reduced in treated mice. Further, a study revealed the involvement of epigenetic regulation by promoter hypermethylation of Col1a1; expressional alterations of transcription factors, calcium channels and other genes e.g., Cbfa-1, Tgf-β1, Bmp1, Sp1, Sp7, Nf-Kb p65, Bmp-2, Bglap, Gprc6a and Cav1.2 are associated with impairment of collagen synthesis, deposition and decreased mineralization thus, enfeebling bone health. This study indicates the possible association of epigenetic regulation in skeletal fluorosis. However, no association was found between polymorphisms in the Col1a1 (RsaI, HindIII) and Col1a2 (RsaI, HindIII) genes with fluorosis in mice.
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Affiliation(s)
- Arpan Dey Bhowmik
- Department of Zoology, Visva-Bharati, Santiniketan, 731235, West Bengal, India
| | - Tanmoy Das
- Department of Zoology, Visva-Bharati, Santiniketan, 731235, West Bengal, India
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Rubio-Gutierrez JC, Mendez-Hernández P, Guéguen Y, Galichon P, Tamayo-Ortiz M, Haupt K, Medeiros M, Barbier OC. Overview of Traditional and Environmental Factors Related to Bone Health. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:31042-31058. [PMID: 35122651 DOI: 10.1007/s11356-022-19024-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/29/2022] [Indexed: 06/14/2023]
Abstract
Bone mass in adulthood depends on growth and mineralization acquired during childhood and adolescence. It is well known that these stages of life are crucial for bone development, where genetic, nutritional, hormonal, and lifestyle factors play a significant role. Bone loss is normally a natural and slow process that begins years later after the peak bone mass is achieved and continues throughout the lifespan. Lifestyle choices in childhood and adolescence such as minimal physical activity, excessive caffeine or carbonated beverages intake, malnutrition, cigarette use, or high alcohol consumption and other factors like environmental pollutants can also negatively affect bone health and accelerate the bone loss process. The aim of this work is an overview of risk factors associated with inadequate bone health in early life.
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Affiliation(s)
- Juan Carlos Rubio-Gutierrez
- Departamento de Toxicología, Centro de Investigación Y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Ciudad de México, CDMX, México
| | - Pablo Mendez-Hernández
- Departamento de Calidad Y Educación en Salud, Secretaría de Salud de Tlaxcala, Tlaxcala, México
- Facultad de Ciencias de La Salud, Universidad Autónoma de Tlaxcala, Tlaxcala, México
| | - Yann Guéguen
- Institut de Radioprotection Et de Sûreté Nucléaire (IRSN), PSE-SANTE, SESANE, Fontenay-aux-Roses, France
| | - Pierre Galichon
- Sorbonne University, GRC 29, DMU DREAM, Assistance Publique-Hôpitaux de Paris, 75013, Paris, France
- Transplantation and Nephrology Department, Hôpital Pitié-Salpétrière, Assistance Publique-Hôpitaux de Paris, 75013, Paris, France
| | - Marcela Tamayo-Ortiz
- Unidad de Investigación en Salud en El Trabajo, Instituto Mexicano del Seguro Social, Centro Médico Siglo XXI, Cuauhtémoc, CDMX, México
| | - Karsten Haupt
- CNRS Enzyme and Cell Engineering Laboratory, Université de Technologie de Compiègne, Rue Roger Couttolenc, CS 60319, 60203, Compiègne Cedex, France
| | - Mara Medeiros
- Unidad de Investigación Y Diagnóstico en Nefrología Y Metabolismo Mineral Óseo, Hospital Infantil de México Federico Gómez (HIMFG), Ciudad de México, CDMX, México
- Departamento de Farmacología, Facultad de Medicina, UNAM, Ciudad de México, CDMX, México
| | - Olivier Christophe Barbier
- Departamento de Toxicología, Centro de Investigación Y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Ciudad de México, CDMX, México.
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Koduganti RR, Gorthi C, Reddy PV, Sandeep N. Osteoporosis: "A risk factor for periodontitis". J Indian Soc Periodontol 2009; 13:90-6. [PMID: 20407657 PMCID: PMC2847131 DOI: 10.4103/0972-124x.55841] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2009] [Accepted: 05/22/2009] [Indexed: 01/05/2023] Open
Abstract
Aging is one of the major health challenges today. Most of the diseases related to aging, lead to significantly increased morbidity and mortality and higher public expenditure of funds. The interconnection between socio-economic conditions and social vulnerability is reflected in precarious states of health with prominence of high rates of osteoporosis and periodontal disease.Both these diseases have been highlighted in public health because of the impact caused by bone fracture and tooth loss. Thus, the elderly could help live a healthier and more meaningful life with the prevention of these diseases.
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Affiliation(s)
- Rekha Rani Koduganti
- Professor and H.O.D, Department of Periodontics, Panineeya Mahavidhyalaya Institute of Dental Sciences and Research, Kamala Nagar, Dilsukhnagar, Hyderabad - 500 060, India
| | - Chandana Gorthi
- Sr. Lecturer, Department of Periodontics, Panineeya Mahavidhyalaya Institute of Dental Sciences and Research, Kamala Nagar, Dilsukhnagar, Hyderabad - 500 060, India
| | - P. Veerendranath Reddy
- Sr. Lecturer, Department of Periodontics, Panineeya Mahavidhyalaya Institute of Dental Sciences and Research, Kamala Nagar, Dilsukhnagar, Hyderabad - 500 060, India
| | - N. Sandeep
- Reader, Department of Periodontics, Panineeya Mahavidhyalaya Institute of Dental Sciences and Research, Kamala Nagar, Dilsukhnagar, Hyderabad - 500 060, India
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Kozhevnikova MN, Mikaelyan AS, Starostin VI. Molecular and genetic regulation of osteogenic differentiation of mesenchymal stromal cells. BIOL BULL+ 2008. [DOI: 10.1134/s1062359008030011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Tsuang YH, Chen LT, Chiang CJ, Wu LC, Chiang YF, Chen PY, Sun JS, Wang CC. Isoflavones prevent bone loss following ovariectomy in young adult rats. J Orthop Surg Res 2008; 3:12. [PMID: 18312690 PMCID: PMC2270812 DOI: 10.1186/1749-799x-3-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2007] [Accepted: 03/02/2008] [Indexed: 11/10/2022] Open
Abstract
Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day) diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy. Dietary isoflavones did not prevent the development of post-ovariectomy bone loss, but long-term ingestion of an isoflavone-rich diet increased the bone mineral contents after ovariectomy in young rats.
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Affiliation(s)
- Yang-Hwei Tsuang
- Department of Orthopedic Surgery, Taipei City Hospital, Taipei, Taiwan, Republic of China
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Alexander D, Hoffmann J, Munz A, Friedrich B, Geis-Gerstorfer J, Reinert S. Analysis of OPLA scaffolds for bone engineering constructs using human jaw periosteal cells. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:965-974. [PMID: 18158613 DOI: 10.1007/s10856-007-3351-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2007] [Accepted: 12/05/2007] [Indexed: 05/25/2023]
Abstract
For bone regeneration constructs using human jaw periosteal cells (JPC) the extent of osteoinductive ability of different three-dimensional scaffolds is not yet established. We analyzed open-cell polylactic acid (OPLA) scaffolds for their suitability as bone engineering constructs using human JPC. Cell adhesion and spreading was visualized on the surface of scaffolds by scanning electron microscopy. JPC proliferation within OPLA scaffolds was compared with proliferation within collagen and calcium phosphate scaffolds. We found a significant increase of proliferation rates in OPLA scaffolds versus Coll/CaP scaffolds at three time points. Live-measurements of oxygen consumption within the cell-seeded scaffolds indicate that the in vitro culturing time should not exceed 12-15 days. OPLA scaffolds, which were turned out to be the most beneficial for JPC growth, were chosen for osteogenic differentiation experiments with or without BMP-2. Gene expression analyses demonstrated induction of several osteogenic genes (alkaline phosphatase, osterix, Runx-2 and insulin-like growth factor) within the 3D-scaffolds after 12 days of in vitro culturing. Element analysis by EDX spectrometry of arising nodules during osteogenesis demonstrated that JPC growing within OPLA scaffolds are able to form CaP particles. We conclude that OPLA scaffolds provide a promising environment for bone substitutes using human JPC.
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Affiliation(s)
- Dorothea Alexander
- Department of Oral and Maxillofacial Surgery, University Hospital Tübingen, Osianderstr. 2-8, 72076, Tubingen, Germany.
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Shin HD, Yang KJ, Park BR, Son CW, Jang HJ, Ku SK. Antiosteoporotic effect of Polycan, β-glucan from Aureobasidium, in ovariectomized osteoporotic mice. Nutrition 2007; 23:853-60. [PMID: 17884343 DOI: 10.1016/j.nut.2007.08.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 05/07/2007] [Accepted: 08/19/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We investigated the anti-osteoporotic effects of Polycan, a beta-glucan from Aureobasidium pullulans, in ovariectomized mice at doses of 31.25, 62.5, and 125 mg/kg. METHODS Polycan was administered orally once a day for 28 d to bilateral ovariectomized mice, beginning 4 wk after surgery. Changes in body weight, bone weight, bone mineral content, bone mineral density, failure load, histologic profiles, and histomorphometric analyses were determined, in addition to serum osteocalcin, calcium, and phosphorus levels. Alendronate was used as a reference drug. RESULTS Polycan significantly and dose-dependently suppressed decreases in bone weight, bone mineral content, failure load, bone mineral density, and serum calcium and phosphorus levels and the increase in serum osteocalcin levels. In addition, Polycan significantly suppressed decreases in histomorphometric parameters such as volume, length, and thickness of trabecular bone and thickness of cortical bone and the increase in osteoclast cells in the femur and tibia. CONCLUSION Although the effects of Polycan were generally modest and smaller than those of alendronate, the effects on cortical bone thickness were more favorable for Polycan than for alendronate. In addition, Polycan exhibited favorable effects on ovariectomy-induced osteoporosis. However, more long-term studies are needed to confirm the effects of Polycan on osteoporosis.
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Affiliation(s)
- Hyun Dong Shin
- Glucan Corp. Research Institute, Marine Biotechnology Center, Gwaebop-dong, Sasanggu, Busan, Republic of Korea
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Merciris D, Marty C, Collet C, de Vernejoul MC, Geoffroy V. Overexpression of the transcriptional factor Runx2 in osteoblasts abolishes the anabolic effect of parathyroid hormone in vivo. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 170:1676-85. [PMID: 17456773 PMCID: PMC1854962 DOI: 10.2353/ajpath.2007.061069] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
There is convincing evidence that Runx2 could be a regulator of the anabolic action of parathyroid hormone (PTH) in bone. We therefore decided to determine how Runx2 overexpression in osteoblasts affects the anabolic response to PTH. Transgenic osteoporotic female mice overexpressing Runx2 (TG) and their wild-type littermates (WT) were treated with PTH (100 microg/kg/day, 7 days a week) or with the vehicle for 6 weeks. Unexpectedly, Runx2 overexpression blunted the increase in the mineral density and volume of bone induced by intermittent PTH in WT mice. Our findings also indicate that PTH failed to increase bone formation in TG mice overexpressing Runx2. This abolition of the effect of PTH by Runx2 overexpression was attributable to a decrease in the differentiation of osteoblastic cells both in vivo and in vitro. Finally, we showed that less cAMP was induced by PTH and that there were fewer PTH binding sites in TG than WT osteoblasts. In conclusion, our findings demonstrate that in vivo a high level of Runx2 abolishes the anabolic effect of PTH, probably via a decrease in the sensitivity of TG osteoblasts to PTH, and that the level of expression of Runx2 is critical if PTH is to produce its anabolic effect on bone in vivo.
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Affiliation(s)
- Nico C Geurs
- Department of Periodontology, School of Dentistry, University of Alabama at Birmingham, USA
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Isenmann S, Cakouros D, Zannettino A, Shi S, Gronthos S. hTERT transcription is repressed by Cbfa1 in human mesenchymal stem cell populations. J Bone Miner Res 2007; 22:897-906. [PMID: 17352650 DOI: 10.1359/jbmr.070308] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
UNLABELLED Human BMSSCs lose telomerase activity in vitro, which leads to chromosomal instability and cellular senescence. We observed an inverse expression pattern between the osteogenic master regulatory gene, CBFA1, and the stem cell-associated gene, hTERT. We showed that Cbfa1 acts as a partial repressor of TERT, which may facilitate cellular differentiation. INTRODUCTION The absence of telomerase activity by cultured human bone marrow stromal stem cells (BMSSCs) causes critical shortening of chromosomal telomeres, leading eventually to cellular senescence. Ex vivo expansion of BMSSCs correlates to an increase in osteogenic lineage associated markers such as alkaline phosphatase, bone sialoprotein, and osteocalcin that are regulated by the master regulatory transcription factor, Cbfa1 (Runx2). This study examined whether Cbfa1 was capable of regulating the promoter of the early stem cell-associated gene, telomerase reverse transcriptase (TERT). MATERIALS AND METHODS Human BMSSCs were isolated by fluorescence-activated cell sorting. Telomerase activity was determined using the telometric repeat amplification protocol. CBFA1 and TERT gene expression was assessed by real-time PCR. The functional capacity of Cbfa1 to bind to the hTERT promoter was performed using a modified electrophoretic mobility shift assay (EMSA). Chromatin immunoprecipitation (ChIP) analysis was used to examine Cbfa1 binding to the hTERT promoter in vivo. Functional analysis of CBFA-1 wildtype and mutant DNA binding sites on TERT promoter fragments was assessed using the promoterless green fluorescence protein (GFP) reporter vector, pEGFP-1, after transfection into HOS cells. RESULTS This study showed an inverse expression pattern between the osteogenic master regulatory gene, CBFA1, and the stem cell-associated gene, hTERT. The data showed that BMSSCs undergo osteogenic commitment after the loss of hTERT expression, with concomitant elevated levels of CBFA1 transcripts. In addition, two unique Cbfa1 DNA binding sites were identified on the hTERT proximal promoter by EMSA supershift assay. Mutated forms of the putative Cbfa1 binding sites, created by site-directed mutagenesis, were able to abolish this interaction. ChIP analysis showed that Cbfa1 interacted directly with the hTERT promoter in vivo. Functional studies using GFP reporter constructs, driven by 2- and 3-kbp hTERT proximal promoter fragments, showed significantly lower levels of transcriptional activity compared with corresponding constructs with mutated Cbfa1 binding site Oligo 2. CONCLUSIONS These studies suggest that Cbfa1 may act as a repressor of early stem cell markers such as hTERT as one possible mechanism for facilitating cellular differentiation.
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Affiliation(s)
- Sandra Isenmann
- Mesenchymal Stem Cell Group, Division of Haematology, Institute of Medical and Veterinary Science/University of Adelaide, South Australia, Australia
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Sørensen MG, Henriksen K, Dziegiel MH, Tankó LB, Karsdal MA. Estrogen Directly Attenuates Human Osteoclastogenesis, But Has No Effect on Resorption by Mature Osteoclasts. DNA Cell Biol 2006; 25:475-83. [PMID: 16907645 DOI: 10.1089/dna.2006.25.475] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Estrogen deficiency arising with the menopause promotes marked acceleration of bone resorption, which can be restored by hormone replacement therapy. The inhibitory effects of estrogen seem to involve indirect cytokine- mediated effects via supporting bone marrow cells, but direct estrogen-receptor mediated effects on the bone-resorbing osteoclasts have also been proposed. Little information is available on whether estrogens modulate human osteoclastogenesis or merely inhibit the functional activity of osteoclasts. To clarify whether estrogens directly modulate osteoclastic activities human CD14+ monocytes were cultured in the presence of M-CSF and RANKL to induce osteoclast differentiation. Addition of 0.1-10 nM 17beta-estradiol to differentiating osteoclasts resulted in a dose-dependent reduction in tartrate resistant acid phosphatase (TRACP) activity reaching 60% at 0.1 nM. In addition, 17beta-estradiol inhibited bone resorption, as measured by the release of the C-terminal crosslinked telopeptide (CTX), by 60% at 0.1 nM, but had no effect on the overall cell viability. In contrast to the results obtained with differentiating osteoclasts, addition of 17beta-estradiol (0.001-10 nM) to mature osteoclasts did not affect bone resorption or TRACP activity. We investigated expression of the estrogen receptors, using immunocytochemistry and Western blotting. We found that ER-alpha is expressed in osteoclast precursors, whereas ER- beta is expressed at all stages, indicating that the inhibitory effect of estrogen on osteoclastogenesis is mediated by ER-alpha for the major part. In conclusion, these results suggest that the in vivo effects of estrogen are mediated by reduction of osteoclastogenesis rather than direct inhibition of the resorptive activity of mature osteoclasts.
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Friedman MS, Long MW, Hankenson KD. Osteogenic differentiation of human mesenchymal stem cells is regulated by bone morphogenetic protein-6. J Cell Biochem 2006; 98:538-54. [PMID: 16317727 DOI: 10.1002/jcb.20719] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Bone marrow-derived mesenchymal stem cells (MSC) are multipotent, self-renewing, mesodermal-origin stem cells that are sequestered in the endosteal compartment. MSC are maintained in a relative state of quiescence in vivo but in response to a variety of physiological and pathological stimuli, proliferate and differentiate into osteoblasts, chondrocytes, adipocytes, or hematopoiesis-supporting stromal cells. Little is understood regarding the cellular or molecular events underlying MSC fate decisions. We report that human MSC (hMSC) cultured in defined, serum-free conditions respond to a narrow spectrum of growth factors with osteogenic commitment, differentiation, and hydroxyapatite deposition. Of the osteogenic factors we examined, only treatment with bone morphogenetic protein (BMP) results in osteoinduction under defined serum-free conditions. Among BMP-2, 4, 6, and 7, BMP-6 is the most consistent and potent regulator of osteoblast differentiation and, of these BMPs, only BMP-6 gene expression is detected prior to hMSC osteoblast differentiation. Addition of exogenous BMP-6 to hMSC induces the expression or upregulation of a repertoire of osteoblast-related genes including type I collagen, osteocalcin, bone sialoprotein, and their regulatory transcription factors Cbfa1/Runx2, and Osterix. This translates into increased production of osteogenic extracellular matrix (ECM) with subsequent hydroxyapatite deposition.
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Affiliation(s)
- Michael S Friedman
- Graduate Program in Cellular and Molecular Biology, University of Michigan, USA
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Lee HW, Suh JH, Kim AY, Lee YS, Park SY, Kim JB. Histone deacetylase 1-mediated histone modification regulates osteoblast differentiation. Mol Endocrinol 2006; 20:2432-43. [PMID: 16728531 DOI: 10.1210/me.2006-0061] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Osteogenesis is a complex process associated with dramatic changes in gene expression. To elucidate whether modifications in chromatin structure are involved in osteoblast differentiation, we examined the expression levels of histone deacetylases (HDACs) and the degree of histone acetylation at the promoter regions of osteogenic genes. During osteogenesis, total HDAC enzymatic activity was decreased with significant reduction in HDAC1 expression. Consistently, recruitment of HDAC1 to the promoters of osteoblast marker genes, including osterix and osteocalcin, was down-regulated, whereas histone H3 and H4 were hyperacetylated at those promoters during osteoblast differentiation. Moreover, suppression of HDAC activity with a HDAC inhibitor, sodium butyrate, accelerated osteogenesis by inducing osteoblast marker genes including osteopontin and alkaline phosphatase. Consistently, knockdown of HDAC1 by the short interference RNA system stimulated osteoblast differentiation. Taken together, these data propose that down-regulation of HDAC1 is an important process for osteogenesis.
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Affiliation(s)
- Hyun Woo Lee
- Department of Biological Sciences, Research Center for Functional Cellulomics, Seoul National University, Seoul, Korea
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