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Kram V, Jani P, Kilts TM, Li L, Chu EY, Young MF. OPG-Fc treatment partially rescues low bone mass phenotype in mature Bgn/Fmod deficient mice but is deleterious to the young mouse skeleton. J Struct Biol 2020; 212:107627. [PMID: 32950603 DOI: 10.1016/j.jsb.2020.107627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 01/12/2023]
Abstract
Biglycan (Bgn) and Fibromodulin (Fmod) are small leucine rich proteoglycans (SLRPs) which are abundant in the extra-cellular matrix (ECM) of mineralized tissues. We have previously generated a Bgn/Fmod double knock-out (DKO) mouse model and found it has a 3-fold increase in osteoclastogenesis compared with Wild type (WT) controls, resulting in a markedly low bone mass (LBM) phenotype. To try and rescue/repair the LBM phenotype of Bgn/Fmod DKO mice by suppressing osteoclast formation and activity, 3- and 26-week-old Bgn/Fmod DKO mice and age/gender matched WT controls were treated with OPG-Fc for 6 weeks after which bone parameters were evaluated using DEXA, micro-computed tomography (μCT) and serum biomarkers analyses. In the appendicular skeleton, OPG-Fc treatment improved some morphometric and geometric parameters in both the trabecular and cortical compartments in Bgn/Fmod DKO female and male mice, especially in the repair module. For many of the skeletal parameters analyzed, the Bgn/Fmod DKO mice were more responsive to the treatment than their WT controls. In addition, we found that OPG-Fc treatment was not able to prevent or ameliorate the formation of ectopic ossification, which are common lesions seen in aged joints and are one of the phenotypical hallmarks of our Bgn/Fmod DKO model. Analysis of skull bones, specifically the occipital bone, showed the treatment recovered some parameters of LBM phenotype in the craniofacial skeleton, more so in the younger rescue module. Using OPG-Fc as treatment alleviated, yet did not completely restore, the severe osteopenia and mineralized tissue structural abnormalities that Bgn/Fmod DKO mice suffer from.
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Affiliation(s)
- Vardit Kram
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Priyam Jani
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Tina M Kilts
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Li Li
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Emily Y Chu
- Laboratory of Oral Connective Tissue Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States
| | - Marian F Young
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, United States.
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Kram V, Shainer R, Jani P, Meester JAN, Loeys B, Young MF. Biglycan in the Skeleton. J Histochem Cytochem 2020; 68:747-762. [PMID: 32623936 DOI: 10.1369/0022155420937371] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Small leucine rich proteoglycans (SLRPs), including Biglycan, have key roles in many organ and tissue systems. The goal of this article is to review the function of Biglycan and other related SLRPs in mineralizing tissues of the skeleton. The review is divided into sections that include Biglycan's role in structural biology, signaling, craniofacial and long bone homeostasis, remodeled skeletal tissues, and in human genetics. While many cell types in the skeleton are now known to be affected by Biglycan, there are still unanswered questions about its mechanism of action(s).
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Affiliation(s)
- Vardit Kram
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, U.S. Department of Health & Human Services, Bethesda, Maryland
| | - Reut Shainer
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, U.S. Department of Health & Human Services, Bethesda, Maryland
| | - Priyam Jani
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, U.S. Department of Health & Human Services, Bethesda, Maryland
| | - Josephina A N Meester
- Laboratory of Cardiogenetics, Center of Medical Genetics, University Hospital Antwerp, University of Antwerp, Antwerp, Belgium
| | - Bart Loeys
- Laboratory of Cardiogenetics, Center of Medical Genetics, University Hospital Antwerp, University of Antwerp, Antwerp, Belgium
| | - Marian F Young
- Molecular Biology of Bones and Teeth Section, National Institutes of Dental and Craniofacial Research, National Institutes of Health, U.S. Department of Health & Human Services, Bethesda, Maryland
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Li C, Ha P, Jiang W, Haveles CS, Zheng Z, Zou M. Fibromodulin - A New Target of Osteoarthritis Management? Front Pharmacol 2019; 10:1475. [PMID: 31920661 PMCID: PMC6927287 DOI: 10.3389/fphar.2019.01475] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/13/2019] [Indexed: 12/15/2022] Open
Affiliation(s)
- Chenshuang Li
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Orthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Division of Growth and Development, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Pin Ha
- Division of Growth and Development, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Wenlu Jiang
- Division of Growth and Development, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Christos S Haveles
- David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA, United States
| | - Zhong Zheng
- Division of Growth and Development, Section of Orthodontics, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Min Zou
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.,Department of Orthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, China
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Farahi L, Ghaemimanesh F, Milani S, Razavi SM, Bayat AA, Rabbani H, Akhondi MM. Monoclonal and Polyclonal Antibodies Specific to Human Fibromodulin. IRANIAN JOURNAL OF BIOTECHNOLOGY 2019; 17:e2277. [PMID: 31457049 PMCID: PMC6697857 DOI: 10.21859/ijb.2277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Background The unique expression of fibromodulin (FMOD) in patients with chronic lymphocytic leukemia (CLL) has been previously reported. Detecting FMOD in CLL patients using specific anti-FMOD mAbs might provide a promising method in detection, monitoring, and prognosis of CLL. Objectives In this study, we aimed for producing specific antibodies against FMOD to facilitate further cohort study of CLL, thus addressing FMOD as a potential target of detection. Materials and Methods Human FMOD gene (1087 bp) was extracted from genome of the CLL patients, and was cloned into the expression vector of pET-22b (+). The recombinant FMOD protein (rFMOD) was expressed in Escherichia coli. The purified rFMOD protein was used as an immunogen in rabbit and mice. Hybridoma technology was used to develop the monoclonal antibodies (mAbs). Polyclonal antibody (pAb) was purified from the rabbit sera using affinity column. The reactivity of anti-FMOD antibodies was assessed in ELISA, immunocytochemistry (ICC) and Western blot. Results ICC results showed that the anti-FMOD antibodies specifically detected FMOD in CLL PBMCs and cell lines. The developed anti-FMOD pAb detected FMOD in CLL lysates, compared to healthy PBMCs, in Western blot and ELISA. Conclusions The developed anti-FMOD mAbs, and pAb specifically detect FMOD in CLL samples and might be used as research tools for further investigations in CLL.
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Affiliation(s)
- Lia Farahi
- Monoclonal Antibody Research Center, Avicenna Research Institute (ACECR), Tehran, Iran
| | - Fatemeh Ghaemimanesh
- Monoclonal Antibody Research Center, Avicenna Research Institute (ACECR), Tehran, Iran
| | - Saeideh Milani
- Monoclonal Antibody Research Center, Avicenna Research Institute (ACECR), Tehran, Iran
| | - Seyed Mohsen Razavi
- Clinic of Hematology and Oncology, Firoozgar Hospital, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Ahmad Bayat
- Monoclonal Antibody Research Center, Avicenna Research Institute (ACECR), Tehran, Iran
| | - Hodjattallah Rabbani
- Monoclonal Antibody Research Center, Avicenna Research Institute (ACECR), Tehran, Iran
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Xu SY, He YB, Deng SY, Liu SY, Xu L, Ni GX. Intensity-dependent effect of treadmill running on rat Achilles tendon. Exp Ther Med 2018; 15:5377-5383. [PMID: 29805550 PMCID: PMC5958711 DOI: 10.3892/etm.2018.6084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/13/2017] [Indexed: 02/05/2023] Open
Abstract
It is understood that mechanical loading may affect tendon properties. However, how different mechanical loading conditions may affect tendons remains unknown. The present study aimed to investigate the effect of treadmill running at various intensities on rat Achilles tendon. A total of 18 male Wistar rats were randomly assigned to one of three groups: Control (CON), medium-intensity running (MIR), and high-intensity running (HIR). Following 8 weeks of treadmill running protocols, all Achilles tendons were harvested for histological observation and gene expression analysis. Significant morphological changes were observed with regular and large diameter collagen fibrils in the MIR group, whereas irregular and small diameter collagen fibrils were observed in the HIR group. Collagen type I was significantly upregulated in the MIR group compared with the CON group, and downregulated in the HIR group compared with the CON or MIR groups (P<0.05). However, collagen type III was significantly upregulated in the HIR group in comparison with the CON or MIR groups (P<0.05). Furthermore, the expression of matrix metallopeptidase-13 was significantly increased in the MIR and HIR groups compared with the CON group (P<0.05). The expression of tissue inhibitor of metalloproteinases-1 was increased in the MIR group compared with the CON group, but decreased in the HIR group compared with the CON and MIR groups (P<0.05). Additionally, decorin expression was significantly higher in the MIR group compared with the CON group, and significantly decreased in the HIR group compared with the CON or MIR groups (P<0.05). A converse pattern of changes in biglycan expression was identified among the three groups. Aggrecan expression was significantly higher in the HIR group compared with the CON or MIR groups (P<0.05). These findings indicated that moderate exercise may induce increased collagen synthesis and organize regular and large collagen fibers, thus benefiting the Achilles tendon. However, overuse during exercise may result in collagen degradation and disturbance, which predisposes individuals to injury.
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Affiliation(s)
- Shao-Yong Xu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Yong-Bin He
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Song-Yun Deng
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Sheng-Yao Liu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Lei Xu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Guo-Xin Ni
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
- Department of Rehabilitation Medicine, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, P.R. China
- Correspondence to: Professor Guo-Xin Ni, Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue, Guangzhou, Guangdong 510515, P.R. China, E-mail:
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Jan AT, Lee EJ, Choi I. Fibromodulin: A regulatory molecule maintaining cellular architecture for normal cellular function. Int J Biochem Cell Biol 2016; 80:66-70. [PMID: 27693429 DOI: 10.1016/j.biocel.2016.09.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/23/2016] [Accepted: 09/28/2016] [Indexed: 01/02/2023]
Abstract
Fibromodulin (FMOD) is a small leucine-rich proteoglycan that plays roles in a series of biological and pathophysiological processes. The interaction between FMOD and lysyl oxidase (LOX; collagen cross-linking enzyme) helps regulate extracellular matrix composition, and thereby, provides a permissive environment for regulating cellular turnover. FMOD has been mostly studied in the context of matrix component assembly, but during recent years its association with muscle development, cell reprogramming, and the angiogenic program have demonstrated its activities well beyond extracellular matrix maintenance. In fact, the involvement of FMOD in these cellular processes places it the centrum of cellular behaviour and ultimately of tissue properties. Thus, a clear view of the impact FMOD has on tissue integrity would aid its exploitation for tissue modelling and in the treatment of different disorders.
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Affiliation(s)
- Arif Tasleem Jan
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Republic of Korea
| | - Eun Ju Lee
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Republic of Korea
| | - Inho Choi
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 38541, Republic of Korea.
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Alfano M, Canducci F, Nebuloni M, Clementi M, Montorsi F, Salonia A. The interplay of extracellular matrix and microbiome in urothelial bladder cancer. Nat Rev Urol 2016; 13:77-90. [PMID: 26666363 PMCID: PMC7097604 DOI: 10.1038/nrurol.2015.292] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many pathological changes in solid tumours are caused by the accumulation of genetic mutations and epigenetic molecular alterations. In addition, tumour progression is profoundly influenced by the environment surrounding the transformed cells. The interplay between tumour cells and their microenvironment has been recognized as one of the key determinants of cancer development and is being extensively investigated. Data suggest that both the extracellular matrix and the microbiota represent microenvironments that contribute to the onset and progression of tumours. Through the introduction of omics technologies and pyrosequencing analyses, a detailed investigation of these two microenvironments is now possible. In urological research, assessment of their dysregulation has become increasingly important to provide diagnostic, prognostic and predictive biomarkers for urothelial bladder cancer. Understanding the roles of the extracellular matrix and microbiota, two key components of the urothelial mucosa, in the sequelae of pathogenic events that occur in the development and progression of urothelial carcinomas will be important to overcome the shortcomings in current bladder cancer treatment strategies.
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Affiliation(s)
- Massimo Alfano
- Division of Experimental Oncology/Unit of Urology, URI, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132 Milan Italy
| | - Filippo Canducci
- Department of Biotechnology and Life Sciences, Università degli Studi dell'Insubria, Via Dunant 3, 21100 Varese Italy
| | - Manuela Nebuloni
- Department of Clinical Sciences, Pathology Unit, L. Sacco Hospital, Università degli Studi di Milano, Via Giovanni Battista Grassi 74, 20157 Milan Italy
| | - Massimo Clementi
- Università Vita-Salute San Raffaele, Via Olgettina 60, 20132 Milan Italy
| | - Francesco Montorsi
- Università Vita-Salute San Raffaele, Via Olgettina 60, 20132 Milan Italy
| | - Andrea Salonia
- Università Vita-Salute San Raffaele, Via Olgettina 60, 20132 Milan Italy
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Defects in tendon, ligament, and enthesis in response to genetic alterations in key proteoglycans and glycoproteins: a review. ARTHRITIS 2013; 2013:154812. [PMID: 24324885 PMCID: PMC3842050 DOI: 10.1155/2013/154812] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/07/2013] [Indexed: 11/17/2022]
Abstract
This review summarizes the genetic alterations and knockdown approaches published in the literature to assess the role of key proteoglycans and glycoproteins in the structural development, function, and repair of tendon, ligament, and enthesis. The information was collected from (i) genetically altered mice, (ii) in vitro knockdown studies, (iii) genetic variants predisposition to injury, and (iv) human genetic diseases. The genes reviewed are for small leucine-rich proteoglycans (lumican, fibromodulin, biglycan, decorin, and asporin); dermatan sulfate epimerase (Dse) that alters structure of glycosaminoglycan and hence the function of small leucine-rich proteoglycans by converting glucuronic to iduronic acid; matricellular proteins (thrombospondin 2, secreted phosphoprotein 1 (Spp1), secreted protein acidic and rich in cysteine (Sparc), periostin, and tenascin X) including human tenascin C variants; and others, such as tenomodulin, leukocyte cell derived chemotaxin 1 (chondromodulin-I, ChM-I), CD44 antigen (Cd44), lubricin (Prg4), and aggrecan degrading gene, a disintegrin-like and metallopeptidase (reprolysin type) with thrombospondin type 1 motif, 5 (Adamts5). Understanding these genes represents drug targets for disrupting pathological mechanisms that lead to tendinopathy, ligamentopathy, enthesopathy, enthesitis and tendon/ligament injury, that is, osteoarthritis and ankylosing spondylitis.
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Friedl G, Schmidt H, Rehak I, Kostner G, Schauenstein K, Windhager R. Undifferentiated human mesenchymal stem cells (hMSCs) are highly sensitive to mechanical strain: transcriptionally controlled early osteo-chondrogenic response in vitro. Osteoarthritis Cartilage 2007; 15:1293-300. [PMID: 17977755 DOI: 10.1016/j.joca.2007.04.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 04/03/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Physical cues play a crucial role in skeletogenesis and osteochondral regeneration. Although human mesenchymal stem cells (hMSCs) offer considerable therapeutic potential, little is known about the molecular mechanisms that control their differentiation. We hypothesized that mechanical strain might be an inherent stimulus for chondrogenic and/or osteogenic differentiation in undifferentiated hMSCs, where c-Fos (FOS) might play a major role in mechanotransduction. METHOD hMSCs from 10 donors were intermittently stimulated by cyclic tensile strain (CTS) at 3000 mustrain for a period of 3 days. Differential gene expression of strained and unstrained hMSCs was analysed by real-time RT-PCR for several marker genes, including the transcription factors FOS, RUNX2, SOX9, and others. Additionally, alkaline phosphatase activity (ALP) was determined kinetically. RESULTS The application of CTS significantly stimulated the expression levels of the early chondrogenic and osteogenic marker genes (SOX9, LUM, DCN; RUNX2, SPARC, SPP1, ALPL); this was accompanied by stimulation of ALP activity (+38%+/-12 standard error of mean, P<0.05). Matrix analysis revealed that the osteo-chondrogenic response followed a coordinated expression pattern, in which FOS was attributed to early osteogenic but not chondrogenic differentiation. CONCLUSION Undifferentiated hMSCs are highly sensitive to mechanical strain with a transcriptionally controlled osteo-chondrogenic differentiation response in vitro.
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Affiliation(s)
- G Friedl
- Department of Orthopaedics and Orthopaedic Surgery, Medical University of Graz, 8036 Graz, Austria
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Lamoureux F, Baud'huin M, Duplomb L, Heymann D, Rédini F. Proteoglycans: key partners in bone cell biology. Bioessays 2007; 29:758-71. [PMID: 17621645 DOI: 10.1002/bies.20612] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The diversity of bone proteoglycan (PG) structure and localisation (pericellular, extracellular in the organic bone matrix) reflects a broad spectrum of biological functions within a unique tissue. PGs play important roles in organizing the bone extracellular matrix, taking part in the structuring of the tissue itself as active regulators of collagen fibrillogenesis. PGs also display selective patterns of reactivity with several constituents including cytokines and growth factors, such as transforming growth factor-beta or osteoprotegerin thereby modulating their bio-availability and biological activity in the bone tissue. In this review, the complex PG composition in bone will be addressed together with the specific role played by PGs (or their GAGs chains) in bone biology, as regulatory molecules for bone resorption and their involvement in bone tumor development. These roles have been determined after modulation of PG expression or mutations in their corresponding genes, which revealed specific roles for these compounds in bone pathologies (e.g. perlecan or glypican-3 mutations observed respectively in chondrodysplasia or dysmorphic syndrome). Finally, the potential therapeutic interest of PGs is discussed based on recent data, more particularly on bone tumor-associated osteolysis as these molecules are involved both in bone resorption and tumor development.
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Affiliation(s)
- François Lamoureux
- EA3822-INSERM ERI7, Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Faculté de Médecine, 1 rue Gaston Veil, 44035 Nantes cedex 1, France
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Oldberg Å, Kalamajski S, Salnikov AV, Stuhr L, Mörgelin M, Reed RK, Heldin NE, Rubin K. Collagen-binding proteoglycan fibromodulin can determine stroma matrix structure and fluid balance in experimental carcinoma. Proc Natl Acad Sci U S A 2007; 104:13966-71. [PMID: 17715296 PMCID: PMC1955775 DOI: 10.1073/pnas.0702014104] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Research on the biology of the tumor stroma has the potential to lead to development of more effective treatment regimes enhancing the efficacy of drug-based treatment of solid malignancies. Tumor stroma is characterized by distorted blood vessels and activated connective tissue cells producing a collagen-rich matrix, which is accompanied by elevated interstitial fluid pressure (IFP), indicating a transport barrier between tumor tissue and blood. Here, we show that the collagen-binding proteoglycan fibromodulin controls stroma structure and fluid balance in experimental carcinoma. Gene ablation or inhibition of expression by anti-inflammatory agents showed that fibromodulin promoted the formation of a dense stroma and an elevated IFP. Fibromodulin-deficiency did not affect vasculature but increased the extracellular fluid volume and lowered IFP. Our data suggest that fibromodulin controls stroma matrix structure that in turn modulates fluid convection inside and out of the stroma. This finding is particularly important in relation to the demonstration that targeted modulations of the fluid balance in carcinoma can increase the response to cancer therapeutic agents.
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Affiliation(s)
- Åke Oldberg
- *Department of Experimental Medical Sciences, BMC, B-12, and
| | | | - Alexei V. Salnikov
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-751 23 Uppsala, Sweden
- Oncology Clinic, University Hospital Lund, SE-221 85 Lund, Sweden
| | - Linda Stuhr
- Department of Biomedicine, University of Bergen, N-5009 Bergen, Norway and
| | - Matthias Mörgelin
- Department of Clinical Sciences, BMC B14, University of Lund, SE-221 84 Lund, Sweden
| | - Rolf K. Reed
- Department of Biomedicine, University of Bergen, N-5009 Bergen, Norway and
| | - Nils-Erik Heldin
- **Department of Genetics and Pathology, Uppsala University Hospital, Rudbeck Laboratory, SE-751 85 Uppsala, Sweden
| | - Kristofer Rubin
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC, Box 582, SE-751 23 Uppsala, Sweden
- To whom correspondence should be addressed. E-mail:
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Majava M, Bishop PN, Hägg P, Scott PG, Rice A, Inglehearn C, Hammond CJ, Spector TD, Ala-Kokko L, Männikkö M. Novel mutations in the small leucine-rich repeat protein/proteoglycan (SLRP) genes in high myopia. Hum Mutat 2007; 28:336-44. [PMID: 17117407 DOI: 10.1002/humu.20444] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The importance of the genetic component in high myopia has been well established in population and family studies, but only a few candidate genes have been explored to date. The extracellular matrix small leucine-rich repeat proteins/proteoglycans (SLRPs) regulate collagen fibril diameter and spacing. Given their role in extracellular matrix assembly and expression in the eye, they are likely to regulate its shape and size. Analysis of 85 English and 40 Finnish subjects with high myopia (refractive error of -6 diopters [D] or greater) resulted in 23 sequence variations in four SLRP genes, LUM, FMOD, PRELP, and OPTC. We observed higher number of variations in OPTC in English patients than in controls (p=0.042), and a possibly protective variation in LUM (c.893-105G>A) with p-value of 0.0043. Two intronic variations, six nonsynonymous and one synonymous amino acid changes, were not found in any of the nonmyopic controls. Five changes were detected in opticin, Thr177Arg, Arg229His, Arg325Trp, Gly329Ser, and Arg330His, and all but one (Arg229His) were shown to cosegregate with high myopia in families with incomplete penetrance. A homology model for opticin revealed that Arg229His and Arg325Trp are likely to disrupt the protein structure, and PolyPhen analysis suggested that Thr177Arg, Arg325Trp, and Gly329Ser changes may be damaging. A Leu199Pro change in lumican and Gly147Asp and Arg324Thr variations in fibromodulin are located in the highly conserved leucine-rich repeat (LRR) domains. This study provides new insight into the genetics of high myopia, suggesting that sequence variations in the SLRP genes expressed in the eye may be among the genetic risk factors underlying the pathogenesis of high myopia.
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Affiliation(s)
- Marja Majava
- Collagen Research Unit, Biocenter and Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
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Muhonen A, Säämänen AM, Peltomäki T, Happonen RP. The effect of irradiation and hyperbaric oxygenation (HBO) on extracellular matrix of the condylar cartilage after mandibular distraction osteogenesis in the rabbit. Int J Oral Maxillofac Surg 2006; 35:79-87. [PMID: 16188425 DOI: 10.1016/j.ijom.2005.06.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 04/27/2005] [Accepted: 06/13/2005] [Indexed: 10/25/2022]
Abstract
The effects of irradiation and hyperbaric oxygenation (HBO) on the extracellular matrix of condylar cartilage after mandibular distraction were evaluated. Unilateral distraction was performed on 19 rabbits. Five study groups were included: control, low- and high-dose irradiation, and low- and high-dose irradiation groups with HBO. Additionally, four temporomandibular joints (TMJ) were used as control material. The high-dose irradiated animals were given in the TMJ 22.4 Gy/4 fractions irradiation (equivalent to 50 Gy/25 fractions). Low-dose irradiation group received a 2.2 Gy dosage. Two groups were also given preoperatively HBO 18 x 2.5ATA x 90 min. After a two-week distraction period (14 mm lengthening) and four-week consolidation period the TMJs were removed. Proteoglycan (PG) distribution of the extracellular matrix was evaluated using safranin O staining and collagen I and II using immunohistochemistry. The organization of fibrillar network was studied by polarized light microscopy. On the operated side of the control group and on the unoperated side in all, except for high-dose irradiated group, PG distribution and fibrillar network were normal appearing. In the irradiated groups, with or without HBO, the cartilaginous layer was partially or totally devoid of PG and the network structure was severely damaged. In conclusion, irradiation in conjunction with the pressure applied by distraction causes severe damage to extracellular matrix of condylar cartilage.
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Affiliation(s)
- A Muhonen
- Department of Oral and Maxillofacial Surgery, University of Turku, Lemminkäisenkatu 2, 20520 Turku, Finland.
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14
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Ekholm E, Tommila M, Forsback AP, Märtson M, Holmbom J, Aäritalo V, Finnberg C, Kuusilehto A, Salonen J, Yli-Urpo A, Penttinen R. Hydroxyapatite coating of cellulose sponge does not improve its osteogenic potency in rat bone. Acta Biomater 2005; 1:535-44. [PMID: 16701833 DOI: 10.1016/j.actbio.2005.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 04/08/2005] [Accepted: 05/10/2005] [Indexed: 11/22/2022]
Abstract
Regenerated cellulose sponges were coated biomimetically with hydroxyapatite to increase their osteogenic properties. Induction of apatite precipitation was carried out with bioactive glass in simulated body fluid (SBF) for 24 h and the final coating was carried out in 1.5 x concentrated SBF for 14 days. Biomimetically mineralized and non-mineralized sponges were then implanted into standard size femoral cortical defects of rats, and the invasion of bone into the implant was followed up to one year. The apatite coating did not improve the osteoconductive property of cellulose in this rat cortical defect model. In fact, it generated a strong and highly cellular inflammatory reaction and less osteoid tissue. The biomimetic implants contained more immunodetectable TGFbeta1 (a strong stimulator of fibroblast activity) than untreated implants, and also bound more TGFbeta1 in vitro, which could, at least in part, explain the fibrotic invasion of biomimetically mineralized sponges.
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Affiliation(s)
- Erika Ekholm
- Department of Medical Biochemistry and Molecular Biology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland
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15
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Mikaelsson E, Danesh-Manesh AH, Lüppert A, Jeddi-Tehrani M, Rezvany MR, Sharifian RA, Safaie R, Roohi A, Osterborg A, Shokri F, Mellstedt H, Rabbani H. Fibromodulin, an extracellular matrix protein: characterization of its unique gene and protein expression in B-cell chronic lymphocytic leukemia and mantle cell lymphoma. Blood 2005; 105:4828-35. [PMID: 15741214 DOI: 10.1182/blood-2004-10-3941] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractFibromodulin is an extracellular matrix protein normally produced by collagen-rich tissues; the fibromodulin gene has been found to be the most overexpressed gene in B-cell chronic lymphocytic leukemia. In this study, fibromodulin was expressed at the gene level (reverse transcription-polymerase chain reaction [RT-PCR]) in all patients with B-CLL (n = 75) and in most (5 of 7) patients with mantle cell lymphoma (MCL). No mutations in the fibromodulin gene were detected. Fibromodulin was also detected at the protein level in the cytoplasm of the B-CLL cells and in the supernatant after in vitro cultivation, but not at the cell surface. Fibromodulin was not found in patients with T-cell chronic lymphocytic leukemia (T-CLL), B-cell prolymphocytic leukemia (B-PLL), T-cell prolymphocytic leukemia (T-PLL), hairy cell leukemia, follicular lymphoma, lymphoplasmacytic lymphoma, multiple myeloma, acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), or chronic myelogenous leukemia (CML) or in 36 hematologic cell lines. Normal blood mononuclear cells (T and B lymphocytes, monocytes), tonsil B cells, and granulocytes did not express fibromodulin. Activation (phorbol 12-myristate 13-acetate [PMA]/ionomycin) of normal T and B lymphocytes induced weak fibromodulin gene expression, but not to the extent seen in freshly isolated B-CLL cells. The reason for the exclusive ectopic expression of fibromodulin in B-CLL and MCL is unknown. However, its unique protein expression makes it likely that fibromodulin is involved in the pathobiology of B-CLL and MCL. (Blood. 2005;105:4828-4835)
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antigens, CD/biosynthesis
- Antigens, CD19/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Biomarkers, Tumor/metabolism
- Blotting, Western
- CD5 Antigens/biosynthesis
- Cell Line, Transformed
- Cell Line, Tumor
- Coculture Techniques
- Collagen/metabolism
- Cytoplasm/metabolism
- DNA Mutational Analysis
- DNA, Complementary/metabolism
- Extracellular Matrix/metabolism
- Extracellular Matrix Proteins/chemistry
- Extracellular Matrix Proteins/metabolism
- Female
- Fibroblasts/metabolism
- Fibromodulin
- Flow Cytometry
- Gene Expression Regulation, Neoplastic
- Hematologic Neoplasms/metabolism
- Humans
- Immunoblotting
- Lectins, C-Type
- Leukemia, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, T-Cell/metabolism
- Leukocytes, Mononuclear/metabolism
- Lymphoma, Mantle-Cell/metabolism
- Male
- Middle Aged
- Mutation
- Palatine Tonsil/metabolism
- Proteoglycans/chemistry
- Proteoglycans/metabolism
- RNA, Messenger/metabolism
- Receptors, Interleukin-2/biosynthesis
- Reverse Transcriptase Polymerase Chain Reaction
- Tetradecanoylphorbol Acetate/pharmacology
- Time Factors
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Affiliation(s)
- Eva Mikaelsson
- Immune and Gene Therapy Laboratory, CCK, Department of Oncology, Karolinska University Hospital, Stockholm, Sweden
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16
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Jepsen KJ, Wu F, Peragallo JH, Paul J, Roberts L, Ezura Y, Oldberg A, Birk DE, Chakravarti S. A syndrome of joint laxity and impaired tendon integrity in lumican- and fibromodulin-deficient mice. J Biol Chem 2002; 277:35532-40. [PMID: 12089156 DOI: 10.1074/jbc.m205398200] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lumican and fibromodulin regulate the assembly of collagens into higher order fibrils in connective tissues. Here, we show that mice deficient in both of these proteoglycans manifest several clinical features of Ehlers-Danlos syndrome. The Lum(-/-)Fmod(-/-) mice are smaller than their wild type littermates and display gait abnormality, joint laxity, and age-dependent osteoarthritis. Misaligned knee patella, severe knee dysmorphogenesis, and extreme tendon weakness are the likely causes for joint laxity in the double-nulls. Fibromodulin deficiency alone leads to significant reduction in tendon stiffness in the Lum(+/+)Fmod(-/-) mice, with further loss in stiffness in a Lum gene dose-dependent way. At the protein level, we show marked increase of lumican in Fmod(-/-) tendons, which may partially rescue the tendon phenotype in this genotype. These results establish fibromodulin as a key regulator and lumican as a modulator of tendon strength. A disproportionate increase in small diameter immature collagen fibrils and a lack of progression to mature, large diameter fibrils in the Fmod(-/-) background may constitute the underlying cause of tendon weakness and suggest that fibromodulin aids fibril maturation. This study demonstrates that the collagen fibril-modifying proteoglycans, lumican and fibromodulin, are candidate genes and key players in the pathogenesis of certain types of Ehlers-Danlos syndrome and other connective tissue disorders.
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Affiliation(s)
- Karl J Jepsen
- Department of Orthopedics, Mount Sinai School of Medicine, New York, New York 10029, USA
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17
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Ameye L, Young MF. Mice deficient in small leucine-rich proteoglycans: novel in vivo models for osteoporosis, osteoarthritis, Ehlers-Danlos syndrome, muscular dystrophy, and corneal diseases. Glycobiology 2002; 12:107R-16R. [PMID: 12213783 DOI: 10.1093/glycob/cwf065] [Citation(s) in RCA: 299] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Small leucine-rich proteoglycans (SLRPs) are extracellular molecules that bind to TGFbetas and collagens and other matrix molecules. In vitro, SLRPs were shown to regulate collagen fibrillogenesis, a process essential in development, tissue repair, and metastasis. To better understand their functions in vivo, mice deficient in one or two of the four most prominent and widely expressed SLRPs (biglycan, decorin, fibromodulin, and lumican) were recently generated. All four SLRP deficiencies result in the formation of abnormal collagen fibrils. Taken together, the collagen phenotypes demonstrate a cooperative, sequential, timely orchestrated action of the SLRPs that altogether shape the architecture and mechanical properties of the collagen matrix. In addition, SLRP-deficient mice develop a wide array of diseases (osteoporosis, osteoarthritis, muscular dystrophy, Ehlers-Danlos syndrome, and corneal diseases), most of them resulting primarily from an abnormal collagen fibrillogenesis. The development of these diseases by SLRP-deficient mice suggests that mutations in SLRPs may be part of undiagnosed predisposing genetic factors for these diseases. Although the distinct phenotypes developed by the different singly deficient mice point to distinct in vivo function for each SLRP, the analysis of the double-deficient mice also demonstrates the existence of rescuing/compensation mechanisms, indicating some functional overlap within the SLRP family.
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Affiliation(s)
- Laurent Ameye
- Craniofacial and Skeletal Diseases Branch, Building 30 Room 225, NIDCR, NIH, Bethesda, MD 20892, USA
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18
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Söderström M, Böhling T, Ekfors T, Nelimarkka L, Aro HT, Vuorio E. Molecular profiling of human chondrosarcomas for matrix production and cancer markers. Int J Cancer 2002; 100:144-51. [PMID: 12115562 DOI: 10.1002/ijc.10457] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chondrosarcoma is the second most common malignant bone tumor, characterized by production of abundant extracellular matrix resembling hyaline cartilage. To better understand the molecular pathogenesis of chondrosarcoma, we analyzed 12 chondrosarcomas for their production of connective tissue components and SOX9, a key regulator of normal chondrocyte differentiation. Furthermore, 10 chondrosarcoma samples were screened for additional changes in gene expression using cDNA array analysis. In Northern analysis, several tumors were found to express type II collagen mRNA at levels comparable to fetal cartilage used as a control. Interestingly, the highest levels of type II collagen mRNA were seen in 2 of the 3 grade 3 chondrosarcomas, which also exhibited the highest mRNA levels of SOX9 and "prechondrogenic" pro alpha 1(IIA) collagen. Expression of SOX9 in human chondrosarcomas is novel and suggests that chondrosarcomas originate from a multipotent stem cell committed to differentiation along the chondrogenic pathway. Results of the cDNA array analyses emphasize the heterogeneous nature of chondrosarcoma as no single transcript was systematically up- or downregulated in all tumors analyzed. Among the interesting changes observed was upregulation of decorin mRNA in 7 of the 10 tumors analyzed. Further studies are needed to determine whether decorin plays a role in the pathogenesis of chondrosarcoma. The cDNA arrays also revealed discrepancies from Northern and RNase protection analyses in transcript levels of matrix components, emphasizing the need to validate cDNA array data with other techniques.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Biomarkers, Tumor/biosynthesis
- Biomarkers, Tumor/genetics
- Blotting, Northern
- Bone Neoplasms/genetics
- Bone Neoplasms/metabolism
- Bone Neoplasms/pathology
- Cell Differentiation/physiology
- Chondrosarcoma/genetics
- Chondrosarcoma/metabolism
- Chondrosarcoma/pathology
- Extracellular Matrix Proteins/biosynthesis
- Extracellular Matrix Proteins/genetics
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- High Mobility Group Proteins/biosynthesis
- High Mobility Group Proteins/genetics
- Humans
- Immunoenzyme Techniques
- Male
- Middle Aged
- Oligonucleotide Array Sequence Analysis
- RNA, Messenger/metabolism
- RNA, Neoplasm/isolation & purification
- SOX9 Transcription Factor
- Sequence Analysis, DNA
- Transcription Factors/biosynthesis
- Transcription Factors/genetics
- Tumor Cells, Cultured/cytology
- Tumor Cells, Cultured/physiology
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Affiliation(s)
- Mirva Söderström
- Skeletal Research Program, Department of Medical Biochemistry and Molecular Biology, University of Turku, Turku, Finland
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19
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Abstract
Lumican and fibromodulin are collagen-binding leucine-rich proteoglycans widely distributed in interstitial connective tissues. The phenotypes of lumican-null (Lum(-/-)), Fibromodulin-null (Fmod(-/-)) and compound double-null (Lum(-/-)Fmod(-/-)) mice identify a broad range of tissues where these two proteoglycans have overlapping and unique roles in modulating the extracellular matrix and cellular behavior. The lumican-deficient mice have reduced corneal transparency and skin fragility. The Lum(-/-)Fmod(-/-) mice are smaller than their wildtype littermates, display gait abnormality, joint laxity and age-dependent osteoarthritis. Misaligned knee patella, severe knee dysmorphogenesis and extreme tendon weakness are the likely cause for joint-laxity. Fibromodulin deficiency alone leads to significant reduction in tendon stiffness in the Lum(+/+)Fmod(-/-) mice, with further loss in stiffness in a lumican gene dose-dependent way. At the level of ultrastructure, the Lum(-/-) cornea, skin and tendon show irregular collagen fibril contours and increased fibril diameter. The Fmod(-/-) tendon contains irregular contoured collagen fibrils, with increased frequency of small diameter fibrils. The tendons of Lum(-/-)Fmod(-/-) have an abnormally high frequency of small and large diameter fibrils indicating a de-regulation of collagen fibril formation and maturation. In tissues like the tendon, where both proteoglycans are present, fibromodulin may be required early in collagen fibrillogenesis to stabilize small-diameter fibril-intermediates and lumican may be needed at a later stage, primarily to limit lateral growth of fibrils
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Affiliation(s)
- Shukti Chakravarti
- Departments of Medicine, Cell Biology and Ophthalmology, Johns Hopkins University, Baltimore, MD 21205, USA.
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20
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Ameye L, Aria D, Jepsen K, Oldberg A, Xu T, Young MF. Abnormal collagen fibrils in tendons of biglycan/fibromodulin-deficient mice lead to gait impairment, ectopic ossification, and osteoarthritis. FASEB J 2002; 16:673-80. [PMID: 11978731 DOI: 10.1096/fj.01-0848com] [Citation(s) in RCA: 268] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Small leucine-rich proteoglycans (SLRPs) regulate extracellular matrix organization, a process essential in development, tissue repair, and metastasis. In vivo interactions of biglycan and fibromodulin, two SLRPs highly expressed in tendons and bones, were investigated by generating biglycan/fibromodulin double-deficient mice. Here we show that collagen fibrils in tendons from mice deficient in biglycan and/or fibromodulin are structurally and mechanically altered resulting in unstable joints. As a result, the mice develop successively and progressively 1) gait impairment, 2) ectopic tendon ossification, and 3) severe premature osteoarthritis. Forced use of the joints increases ectopic ossification and osteoarthritis in the double-deficient mice, further indicating that structurally weak tendons cause the phenotype. The study shows that mutations in SLRPs may predispose to osteoarthritis and offers a valuable and unique animal model for spontaneous osteoarthritis characterized by early onset and a rapid progression of the disease.
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Affiliation(s)
- Laurent Ameye
- Craniofacial and Skeletal Diseases Branch, NIDCR, National Institutes of Health, Bethesda, Maryland, USA.
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21
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Ekholm E, Hankenson KD, Uusitalo H, Hiltunen A, Gardner H, Heino J, Penttinen R. Diminished callus size and cartilage synthesis in alpha 1 beta 1 integrin-deficient mice during bone fracture healing. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 160:1779-85. [PMID: 12000729 PMCID: PMC1850876 DOI: 10.1016/s0002-9440(10)61124-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Integrins mediate cell adhesion to extracellular matrix components. Integrin alpha 1 beta 1 is a collagen receptor expressed on many mesenchymal cells, but mice deficient in alpha 1 integrin (alpha1-KO) have no gross structural defects. Here, the regeneration of a fractured long bone was studied in alpha1-KO mice. These mice developed significantly less callus tissue than the wild-type (WT) mice, and safranin staining revealed a defect in cartilage formation. The mRNA levels of nine extracellular matrix genes in calluses were evaluated by Northern blotting. During the first 9 days the mRNA levels of cartilage-related genes, including type II collagen, type IX collagen, and type X collagen, were lower in alpha1-KO mice than in WT mice, consistent with the reduced synthesis of cartilaginous matrix appreciated in tissue sections. Histological observations also suggested a diminished number of chondrocytes in the alpha 1-KO callus. Proliferating cell nuclear antigen staining revealed a reduction of mesenchymal progenitors at the callus site. Although, the number of mesenchymal stem cells (MSCs) obtained from WT and alpha 1-KO whole marrow was equal, in cell culture the proliferation rate of the MSCs of alpha 1-KO mice was slower, recapitulating the in vivo observation of reduced callus cell proliferation. The results demonstrate the importance of proper collagen-integrin interaction in fracture healing and suggest that alpha1 integrin plays an essential role in the regulation of MSC proliferation and cartilage production.
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Affiliation(s)
- Erika Ekholm
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Kurt D. Hankenson
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Hannele Uusitalo
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Ari Hiltunen
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Humphrey Gardner
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Jyrki Heino
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
| | - Risto Penttinen
- From the Departments of Medical Biochemistry and Molecular Biology,*Surgery,‡and the MediCity Research Laboratory,§University of Turku, Turku, Finland; Biogen Limited,¶Cambridge, Massachusetts; and the Orthopaedic Research Laboratories,†University of Michigan, Ann Arbor, Michigan
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