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Sun C, Zhang H, Wang X, Liu X. Ligamentum flavum fibrosis and hypertrophy: Molecular pathways, cellular mechanisms, and future directions. FASEB J 2020; 34:9854-9868. [PMID: 32608536 DOI: 10.1096/fj.202000635r] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 12/11/2022]
Abstract
Hypertrophy of ligamentum flavum (LF), along with disk protrusion and facet joints degeneration, is associated with the development of lumbar spinal canal stenosis (LSCS). Of note, LF hypertrophy is deemed as an important cause of LSCS. Histologically, fibrosis is proved to be the main pathology of LF hypertrophy. Despite the numerous studies explored the mechanisms of LF fibrosis at the molecular and cellular levels, the exact mechanism remains unknown. It is suggested that pathophysiologic stimuli such as mechanical stress, aging, obesity, and some diseases are the causative factors. Then, many cytokines and growth factors secreted by LF cells and its surrounding tissues play different roles in activating the fibrotic response. Here, we summarize the current status of detailed knowledge available regarding the causative factors, pathology, molecular and cellular mechanisms implicated in LF fibrosis and hypertrophy, also focusing on the possible avenues for anti-fibrotic strategies.
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Affiliation(s)
- Chao Sun
- Department of Spine Surgery, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
| | - Han Zhang
- Department of Spine Surgery, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
| | - Xiang Wang
- Department of Spine Surgery, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
| | - Xinhui Liu
- Department of Spine Surgery, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
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Shi L, Cai G, Shi J, Guo Y, Chen D, Chen D, Yang H. Ossification of the posterior ligament is mediated by osterix via inhibition of the β-catenin signaling pathway. Exp Cell Res 2016; 349:53-59. [PMID: 27693496 DOI: 10.1016/j.yexcr.2016.09.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 09/26/2016] [Accepted: 09/28/2016] [Indexed: 11/29/2022]
Abstract
Ossification of the posterior longitudinal ligament (OPLL) involves ectopic calcification of the spinal ligament preferentially at the cervical spine. OPLL is associated with different diseases and occurs by endochondral ossification, which is associated with the activity of different transcription factors. However, the pathogenesis of OPLL remains unclear. Here, we investigated the role of osterix (Osx), a transcription factor that functions downstream of Runx2 and is an important regulator of osteogenesis, in the process of OPLL in a dexamethasone (Dex)-induced model of spinal ligament ossification. Our results showed that Osx is upregulated in patients with OPLL and during the ossification of ligament cells in parallel with the upregulation of osteogenic markers including osteocalcin (OCN), alkaline phosphatase (ALP) and collagen-1 (Col-1). Dex-induced ossification of ligament cells was associated with the downregulation and inactivation of β-catenin, and these effects were offset by Osx knockdown. Activation of β-catenin signaling abolished the effect of Dex on ossification and the upregulation of osteogenic markers. Taken together, our results suggest that OPLL is mediated by Osx via a mechanism involving the Wnt/β-catenin signaling pathway, providing a basis for further research to identify potential targets for the treatment of OPLL.
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Affiliation(s)
- Lei Shi
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China
| | - Guodong Cai
- Department of Orthopedics, Affiliated Hospital of Taishan Medical University, 706 Taishan Street, Tai'an 271000, Shangdong Province, China
| | - Jiangang Shi
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China
| | - Yongfei Guo
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China
| | - Dechun Chen
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China
| | - Deyu Chen
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China
| | - Haisong Yang
- Department of Orthopedics, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, China.
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Hou XF, Fan DW, Sun CG, Chen ZQ. Recombinant human bone morphogenetic protein-2-induced ossification of the ligamentum flavum in rats and the associated global modification of histone H3. J Neurosurg Spine 2014; 21:334-41. [PMID: 24949905 DOI: 10.3171/2014.4.spine13319] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECT The primary object of this investigation was to study recombinant human bone morphogenetic protein-2 (rhBMP-2)-induced ossification of the ligamentum flavum and associated histone H3 modification in a rat model. In an additional set of studies the authors investigated spinal cord and behavioral changes in the same model. METHODS The authors report on 2 separate sets of studies. A total of 90 rats were used for the 2 sets of studies (45 each); in each study, a lyophilized rhBMP-2 and collagen mixture (20 μg rhBMP-2 and 200 μl collagen) was implanted in the lumbar extradural space in 18 rats; another 18 animals were used for a sham-operation control group and underwent implantation of lyophilized collagen without rhBMP-2 at the same level; an additional 9 animals were used as untreated controls. Lumbar spinal samples were harvested from the rhBMP-2 groups and the shamoperation control groups at 1 week, 3 weeks, and 9 weeks after the operation. Samples were also obtained from untreated controls at the same time points. All samples were scanned using micro-CT and then made into paraffinembedded sections. The sections from the first set of 45 rats were stained using elastica van Gieson and toluidine blue, and the expression of histone modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) and osteogenic transcription factors (osterix, Runx2) was detected by immunohistochemistry. In the second set of studies, hindlimb motor function was assessed at 1 week, 3 weeks, and 9 weeks after surgery. After behavioral evaluation, samples were harvested, scanned using micro-CT, and then made into paraffin-embedded sections. The sections were stained using Luxol fast blue. The expression of NeuN was also detected using immunohistochemistry. RESULTS Ossification was seen in the rhBMP-2 group from 1 week after insertion, and the volume of ossified mass increased at 3 and 9 weeks. There was no ossification seen in the sham-surgery and normal controls. The pathological changes of ossification involved ligament degeneration, cartilage formation, and, finally, bone replacement. Spinal cord evaluation showed a significant decrease in white matter content and number of neurons at 9 weeks after operation in the rhBMP-2-treated group (compared with findings in the sham-surgery and control groups as well as findings at the earlier time points in the rhBMP-2 group). Using immunohistochemical staining, histone modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) and osteogenic transcription factors (osterix, Runx2) all were found to be expressed in the fibrocartilage area of the rat ossified ligamentum flavum samples (rhBMP2 group). CONCLUSIONS This rhBMP-2-induced OLF is a typical endochondral ossification, which is similar to clinical OLF. The compressed spinal cord around the ossification site showed signs of a chronic degenerative process. Histone H3 modifications (H3K9ac, H3K18ac, H3K4me3, and H3K36me3) may play an important role in OLF.
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Affiliation(s)
- Xiao-Fei Hou
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
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Lui PPY. Histopathological changes in tendinopathy--potential roles of BMPs? Rheumatology (Oxford) 2013; 52:2116-2126. [DOI: 10.1093/rheumatology/ket165] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Oliva F, Via AG, Maffulli N. Physiopathology of intratendinous calcific deposition. BMC Med 2012; 10:95. [PMID: 22917025 PMCID: PMC3482552 DOI: 10.1186/1741-7015-10-95] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 08/23/2012] [Indexed: 01/22/2023] Open
Abstract
In calcific tendinopathy (CT), calcium deposits in the substance of the tendon, with chronic activity-related pain, tenderness, localized edema and various degrees of decreased range of motion. CT is particularly common in the rotator cuff, and supraspinatus, Achilles and patellar tendons. The presence of calcific deposits may worsen the clinical manifestations of tendinopathy with an increase in rupture rate, slower recovery times and a higher frequency of post-operative complications. The aetiopathogenesis of CT is still controversial, but seems to be the result of an active cell-mediated process and a localized attempt of the tendon to compensate the original decreased stiffness. Tendon healing includes many sequential processes, and disturbances at different stages of healing may lead to different combinations of histopathological changes, diverting the normal healing processes to an abnormal pathway. In this review, we discuss the theories of pathogenesis behind CT. Better understanding of the pathogenesis is essential for development of effective treatment modalities and for improvement of clinical outcomes.
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Affiliation(s)
- Francesco Oliva
- Department of Orthopaedics and Traumatology, University of Rome 'Tor Vergata' School of Medicine, Viale Oxford 81, Rome, Italy
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Isolation of mesenchymal stem cells from human ligamentum flavum: implicating etiology of ligamentum flavum hypertrophy. Spine (Phila Pa 1976) 2011; 36:E1193-200. [PMID: 21343850 DOI: 10.1097/brs.0b013e3182053f58] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN To demonstrate the existence of mesenchymal stem cells (MSCs) in ligamentum flavum (LF) and their pathogenic role in LF hypertrophy. OBJECTIVE To isolate and characterize LF-derived MSCs and their response to transforming growth factor-beta 1 (TGF-β1) and trichostatin A (TSA), a histone deacetylase inhibitor (HDACi). SUMMARY OF BACKGROUND DATA LF is a connective tissue, of which hypertrophic changes induce spinal stenosis. The pathogenic role of TGF-β1 in spinal stenosis has been implicated. TSA has been shown to suppress TGF-β1-induced alpha-smooth muscle actin (α-SMA), type I and III collagen synthesis in a variety of cells. MSCs have been isolated from a variety of adult tissues, except LF. Whether MSCs exist in LF and their response to TGF-β1 and TSA is not clear. METHODS The MSCs from LF were isolated and cultured. Their phenotypic character, linage differentiation potential, and response to TGF-β1 and TSA were analyzed. RESULTS LF-derived MSCs have the similar profile of surface markers as bone marrow MSCs. They were demonstrated to have the potential to be differentiated into osteoblasts, adipocytes, and chondrocytes. Administration of TGF-β1 stimulated cell proliferation, enhanced the gene expression of type I and III collagen, and increased the gene expression and protein level of α-SMA. TSA blocked the fibrogenic effects of TGF-β1. CONCLUSION The current results demonstrated the isolation of MSCs from LF. The cellular response to TGF-β1 implied that these cells might play an important role in the pathogenesis of LF hypertrophy. TSA, which blocks the effects of TGF-β1, may be a potent therapeutic choice for inhibiting LF hypertrophy.
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Lui PPY, Maffulli N, Rolf C, Smith RKW. What are the validated animal models for tendinopathy? Scand J Med Sci Sports 2011; 21:3-17. [PMID: 20673247 DOI: 10.1111/j.1600-0838.2010.01164.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chronic tendinopathy refers to a broad spectrum of pathological conditions in tendons and their insertion, with symptoms including activity-related chronic pain. To study the pathogenesis and management strategies of chronic tendinopathy, studies in animal models are essential. The different animal models in the literature present advantages and limitations, and there is no consensus regarding the criteria of a universal tendinopathy animal model. Based on the review of literature and the discussion in the International Symposium on Ligaments and Tendons-X, we concluded that established clinical, histopathological and functional characteristics of human tendinopathy were all important and relevant criteria to be met, if possible, by animal models. As tendinopathy is a progressive, multifactorial tendon disorder affecting different anatomical structures, it may not be realistic to expect a single animal model to study all aspects of tendinopathy. Staging of tendinopathy over time and clearer definition of tendinopathies in relation to severity and type would enable realistic targets with any animal model. The existing animal models can be used for answering specific questions (horses for courses) but should not be used to conclude the general aspects of tendinopathy neither in animals nor in human.
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Affiliation(s)
- P P Y Lui
- Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Kudo H, Furukawa KI, Yokoyama T, Ono A, Numasawa T, Wada K, Tanaka S, Asari T, Ueyama K, Motomura S, Toh S. Genetic differences in the osteogenic differentiation potency according to the classification of ossification of the posterior longitudinal ligament of the cervical spine. Spine (Phila Pa 1976) 2011; 36:951-7. [PMID: 21224767 DOI: 10.1097/brs.0b013e3181e9a8a6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN We categorized the four types of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine into two groups. We biochemically investigated the genetic differences in the osteogenic differentiation potency between the two groups. OBJECTIVE To investigate the genetic differences in the osteogenic differentiation potency according to the OPLL classification. SUMMARY OF BACKGROUND DATA Clinical studies on OPLL have revealed that the risk of progression of the ossification area is greatest for continuous and mixed type OPLL. However, until now, these four types of OPLL have been studied as a single condition. METHODS We categorized the four types of OPLL into the OPLL continuous (continuous or mixed type) and OPLL segmental groups (segmental or circumscribed type). Paraspinal ligaments were aseptically obtained from OPLL patients during surgery. The fibroblast-like cells that migrated from the explants were used for experiments. The cells were placed in a 60-mm culture dishes for total ribonucleic acid preparation and 12 well microplates for alkaline phosphatase (ALP) activity staining. After cultures reached confluence, the cells were cultured in osteogenic medium. The messenger ribonucleic acid expression of bone morphogenetic protein-2 (BMP-2), osterix, tumor necrosis factor-α-stimulated gene-6, and ALP was analyzed by quantitative real time-polymerase chain reaction. Osteogenic differentiation of fibroblast-like cells was determined by histochemically detecting ALP production. RESULTS After osteogenic induction, BMP-2 expression increased in the OPLL continuous and segmental groups. Osterix expression increased in the OPLL continuous group only. Tumor necrosis factor-α-stimulated gene-6 expression was suppressed in the OPLL continuous and segmental groups. ALP expression as well as ALP activity staining was higher in the OPLL continuous group than in the OPLL segmental group. CONCLUSION.: The study revealed genetic differences in the osteogenic differentiation potency between the OPLL continuous and segmental groups. We propose to distinguish OPLL continuous group from segmental group in biochemical studies on OPLL.
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Affiliation(s)
- Hitoshi Kudo
- Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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Lui PPY, Chan LS, Lee YW, Fu SC, Chan KM. Sustained expression of proteoglycans and collagen type III/type I ratio in a calcified tendinopathy model. Rheumatology (Oxford) 2010; 49:231-239. [DOI: 10.1093/rheumatology/kep384] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Wang L, Singh M, Bonewald LF, Detamore MS. Signalling strategies for osteogenic differentiation of human umbilical cord mesenchymal stromal cells for 3D bone tissue engineering. J Tissue Eng Regen Med 2009; 3:398-404. [PMID: 19434662 DOI: 10.1002/term.176] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Human umbilical cord mesenchymal stromal cells (hUCMSCs) have recently shown the capacity to differentiate into multiple cell lineages in all three embryonic germ layers. The osteogenic differentiation of hUCMSCs in monolayer culture has been reported, while the differentiation in three-dimensional biomaterials has not yet been reported for tissue-engineering applications. Thus, the aim of this study was to evaluate the feasibility of using hUCMSCs for bone tissue engineering. hUCMSCs were cultured in poly(L-lactic acid) (PLLA) scaffolds in osteogenic medium (OM) for 3 weeks, after which the scaffolds were exposed to several different media, including the OM, a mineralization medium (MM) and the MM with either 10 or 100 ng/ml insulin-like growth factor (IGF)-1. The osteogenic differentiation was confirmed by the up-regulation of Runx2 and OCN, calcium quantification and bone histology. Switching from the OM to the MM promoted collagen synthesis and calcium content per cell, while continuing in the OM retained more cells in the constructs and promoted higher osteogenic gene expression. The addition of IGF-1 into the MM had no effect on cell proliferation, differentiation and matrix synthesis. In conclusion, hUCMSCs show significant potential for bone tissue engineering and culturing in the OM throughout the entire period is beneficial for osteogenic differentiation of these cells.
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Affiliation(s)
- Limin Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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Orciani M, Trubiani O, Vignini A, Mattioli-Belmonte M, Di Primio R, Salvolini E. Nitric oxide production during the osteogenic differentiation of human periodontal ligament mesenchymal stem cells. Acta Histochem 2009; 111:15-24. [PMID: 18554689 DOI: 10.1016/j.acthis.2008.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 02/08/2008] [Accepted: 02/19/2008] [Indexed: 12/20/2022]
Abstract
The critical tissues that require regeneration in the periodontium are of mesenchymal origin; therefore, the ability to identify, characterize and manipulate mesenchymal stem cells within the periodontium is of considerable clinical significance. In particular, recent findings suggest that periodontal ligament cells may possess many osteoblast-like properties. In the present study, periodontal ligament mesenchymal stem cells obtained from healthy volunteers were maintained in culture until confluence and then induced to osteogenic differentiation. Intracellular calcium ([Ca2+](i)) concentration and nitric oxide, important signalling molecules in the bone, were measured along with cell differentiation. Alkaline phosphatase activity was assayed and bone nodule-like structures were evaluated by means of morphological and histochemical analysis. Our results showed that the periodontal ligament mesenchymal stem cells underwent an in vitro osteogenic differentiation, resulting in the appearance of active osteoblast-like cells together with the formation of calcified deposits. Differentiating cells were also characterized by an increase of [Ca2+](i) and nitric oxide production. In conclusion, our data show a link between nitric oxide and the osteogenic differentiation of human periodontal ligament mesenchymal stem cells, thus suggesting that local reimplantation of expanded cells in conjugation with a nitric oxide donor could represent a promising method for treatment of periodontal defects.
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Kishiya M, Sawada T, Kanemaru K, Kudo H, Numasawa T, Yokoyama T, Tanaka S, Motomura S, Ueyama K, Harata S, Toh S, Furukawa KI. A functional RNAi screen for Runx2-regulated genes associated with ectopic bone formation in human spinal ligaments. J Pharmacol Sci 2008; 106:404-14. [PMID: 18319563 DOI: 10.1254/jphs.fp0072043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by ectopic ossification in the spinal ligaments, which enlarges with time and compresses the spinal cord, resulting in serious neurological symptoms. We previously reported that Runx2 expression was enhanced in spinal ligament cells from OPLL patients (OPLL cells). To clarify genes regulated by Runx2, Runx2 expression was first enhanced by culturing primary OPLL cells in osteogenic medium (OS induction) and then inhibited by siRNAs targeted to Runx2. DNA microarray demonstrated that in addition to chondrogenic factors such as connective tissue growth factor and cartilage oligomeric matrix protein, angiopoietin-1 was also significantly increased by OS induction and decreased by siRNAs for Runx2 in OPLL cells, suggesting that these genes are regulated by Runx2. However, these changes were not observed in non-OPLL control cells (from cervical spondylotic myelopathy patients). Furthermore, Runx2 was not decreased by siRNAs for angiopoietin-1. OS induction and RNAi inhibition of angiopoietin-1 expression was also observed in osteoblasts. Both siRNAs for Runx2 and angiopoietin-1 completely inhibited aggrecan-1 expression. These results suggest that angiopoietin-1 is downstream of Runx2 in both OPLL primary cells and osteoblasts. Angiopoietin-1 may play an important role in ectopic ossification.
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Affiliation(s)
- Masaki Kishiya
- Department of Pharmacology, Hirosaki University Graduate School of Medicine, Japan
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Jang K, Sato K, Igawa K, Chung UI, Kitamori T. Development of an osteoblast-based 3D continuous-perfusion microfluidic system for drug screening. Anal Bioanal Chem 2007; 390:825-32. [PMID: 18084748 DOI: 10.1007/s00216-007-1752-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 11/08/2007] [Accepted: 11/12/2007] [Indexed: 11/28/2022]
Abstract
In this work, we demonstrated that biological cells could be cultured in a continuous-perfusion glass microchip system for drug screening. We used mouse Col1a1GFP MC-3T3 E1 osteoblastic cells, which have a marker gene system expressing green fluorescent protein (GFP) under the control of osteoblast-specific promoters. With our microchip-based cell culture system, we realized automated long-term monitoring of cells and sampling of the culture supernatant system for osteoblast differentiation assay using a small number of cells. The system successfully monitored cells for 10 days. Under the 3D microchannel condition, shear stress (0.07 dyne/cm(2) at a flow rate of 0.2 microL/min) was applied to the cells and it enhanced the GFP expression and differentiation of the osteoblasts. Analysis of alkaline phosphatase (ALP), which is an enzyme marker of osteoblasts, supported the results of GFP expression. In the case of differentiation medium containing bone morphogenetic protein 2, we found that ALP activity in the culture supernatant was enhanced 10 times in the microchannel compared with the static condition in 48-well dishes. A combined system of a microchip and a cell-based sensor might allow us to monitor osteogenic differentiation easily, precisely, and noninvasively. Our system can be applied in high-throughput drug screening assay for discovering osteogenic compounds.
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Affiliation(s)
- Kihoon Jang
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan
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Clausen C, Hermund NU, Donatsky O, Nielsen H. Characterization of human bone cells derived from the maxillary alveolar ridge. Clin Oral Implants Res 2006; 17:533-40. [PMID: 16958693 DOI: 10.1111/j.1600-0501.2006.01254.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In this study, we have characterized bone cell cultures derived from the human maxillary alveolar ridge, which could be a potential cell source for tissue engineering of the severely resorbed maxilla. From 10 individuals, an osseous core was obtained. Without the use of collagenase, 10 explant cultures were established and the morphology of the cells (human maxilla-derived cells (hMDCs)) was studied with light microscopy (LM). Explant cultures were analyzed by flow cytometry with respect to size, granularity and surface marker expression. Fluorochrom-conjugated monoclonal antibodies (CD13, CD31, CD44, CD90 or CD73) were used. hMDCs were cultured in standard medium (SCM) or osteoinductive medium (OIM) for 21 days and analyzed for the presence of alkaline phosphatase (ALP) and calcium deposits (Von Kossa). Furthermore, osteogenic gene expression (osteocalcin [OC], ALP, collagen type 1) were analyzed by reverse transcription polymerase chain reaction (RT-PCR). LM demonstrated that hMDCs had a polygonal morphology containing a central nucleus with two to three nucleoli. Size/granularity analysis revealed differences between individuals. Immunophenotypically, these cells were positive for CD13, CD44, CD90 and CD73 while negative for CD31. Cells cultured in SCM for 21 days showed moderate ALP staining and many calcium deposits. Culturing cells in OIM for 21 days significantly increased both ALP staining and the number of calcium deposits. RT-PCR demonstrated expression of osteogenic marker genes and the ability to upregulate osteocalcin and ALP in response to osteogenic inducers. To our knowledge, it is the first time that surface marker expression has been studied on bone cells originating from this site. Cells were positive for markers characteristic for immature mesenchymal stem cells and had osteogenic differentiation capability. This study indicates that cells derived from maxillary biopsies could be a potential cell source for bone tissue engineering.
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Affiliation(s)
- Christian Clausen
- Interface Biotech A/S, c/o Glostrup Hospital, Opgang 8, 4. sal. 2600 Glostrup, Denmark.
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