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Predicting Transport of Intra-Articularly Injected Growth Factor Fusion Proteins into Human Knee Joint Cartilage. Acta Biomater 2022; 153:243-259. [DOI: 10.1016/j.actbio.2022.09.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 11/23/2022]
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Morales T, Stearns-Yoder K, Hoffberg A, Khan T, Wortzel H, Brenner L. Interactions of Glutamate and Gamma Amino Butyric Acid with the Insulin-like growth factor system in Traumatic Brain Injury (TBI) and/or Cardiovascular Accidents (CVA or stroke): A systematic review. Heliyon 2022; 8:e09037. [PMID: 35309405 PMCID: PMC8928062 DOI: 10.1016/j.heliyon.2022.e09037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/28/2021] [Accepted: 02/25/2022] [Indexed: 12/14/2022] Open
Abstract
The brain maintains homeostasis of neural excitation in part through the receptor-mediated signaling of Glutamate (Glu) and Gamma Amino Butyric Acid (GABA), but localized injuries cause cellular release of excess Glu leading to neurotoxicity. The literature strongly supports the role of Insulin-like growth factor-1 (IGF-1) in adult brain neuroprotection and repair, and research supporting the existence of molecular interactions between Glu, GABA, and IGF-1 in vitro and in normal animals raises the question of whether and/or how the Glu/GABA system interacts with IGF-1 post-injury. This systematic review was undertaken to explore works addressing this question among adults with a history of traumatic brain injury (TBI) and/or cerebrovascular accident (CVA; stroke). The literature was searched for human and animal studies and only four animal papers met inclusion criteria. The SYRCLE criteria was used to evaluate risk of bias; results varied between categories and papers. All the included studies, one on TBI and three on stroke, supported the molecular relationship between the excitatory and IGF-1 systems; two studies provided direct, detailed molecular evidence. The results point to the importance of research on the role of this protective system in pathological brain injury; a hypothetical proposal for future studies is presented.
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Affiliation(s)
- T.I. Morales
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
- Department of Physical Medicine and Rehabilitation, University of Colorado, Anschutz School of Medicine, United States
- Corresponding author.
| | - K.A. Stearns-Yoder
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
- Department of Physical Medicine and Rehabilitation, University of Colorado, Anschutz School of Medicine, United States
| | - A.S. Hoffberg
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
| | - T.K. Khan
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
| | - H. Wortzel
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
- Department of Physical Medicine and Rehabilitation, University of Colorado, Anschutz School of Medicine, United States
- Department of Neurology, University of Colorado, Anschutz School of Medicine, United States
- Department of Psychiatry, University of Colorado, Anschutz School of Medicine, United States
| | - L.A. Brenner
- VA Rocky Mountain Mental Illness Research, Education and Clinical Center, University of Colorado, Anschutz School of Medicine, United States
- Department of Physical Medicine and Rehabilitation, University of Colorado, Anschutz School of Medicine, United States
- Department of Neurology, University of Colorado, Anschutz School of Medicine, United States
- Department of Psychiatry, University of Colorado, Anschutz School of Medicine, United States
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Mesenchymal Stem/Stromal Cells seeded on cartilaginous endplates promote Intervertebral Disc Regeneration through Extracellular Matrix Remodeling. Sci Rep 2016; 6:33836. [PMID: 27652931 PMCID: PMC5031983 DOI: 10.1038/srep33836] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/05/2016] [Indexed: 12/11/2022] Open
Abstract
Intervertebral disc (IVD) degeneration is characterized by significant biochemical and histomorphological alterations, such as loss of extracellular matrix (ECM) integrity, by abnormal synthesis of ECM main components, resultant from altered anabolic/catabolic cell activities and cell death. Mesenchymal Stem/Stromal Cell (MSC) migration towards degenerated IVD may represent a viable strategy to promote tissue repair/regeneration. Here, human MSCs (hMSCs) were seeded on top of cartilaginous endplates (CEP) of nucleotomized IVDs of bovine origin and cultured ex vivo up to 3 weeks. hMSCs migrated from CEP towards the lesion area and significantly increased expression of collagen type II and aggrecan in IVD, namely in the nucleus pulposus. Concomitantly, hMSCs stimulated the production of growth factors, promoters of ECM synthesis, such as fibroblast growth factor 6 (FGF-6) and 7 (FGF-7), platelet-derived growth factor receptor (PDGF-R), granulocyte-macrophage colony-stimulating factor (GM-CSF) and insulin-like growth factor 1 receptor (IGF-1sR). Overall, our results demonstrate that CEP can be an alternative route to MSC-based therapies for IVD regeneration through ECM remodeling, thus opening new perspectives on endogenous repair capacity through MSC recruitment.
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Uchimura T, Foote AT, Smith EL, Matzkin EG, Zeng L. Insulin-Like Growth Factor II (IGF-II) Inhibits IL-1β-Induced Cartilage Matrix Loss and Promotes Cartilage Integrity in Experimental Osteoarthritis. J Cell Biochem 2016; 116:2858-69. [PMID: 26015264 DOI: 10.1002/jcb.25232] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 05/14/2015] [Indexed: 12/21/2022]
Abstract
Osteoarthritis (OA) is a widespread chronic joint disease characterized by articular cartilage destruction and accompanied by pain and disability. In this study, we found that the expression of Insulin-like Growth Factor II (IGF-II) was reduced in articular cartilage in human OA patients as well as in the murine experimental OA model of destabilization of the medial meniscus (DMM). In primary human articular chondrocytes, ectopic expression of lentiviral IGF-II inhibited pro-inflammatory cytokine IL-1β-induced NF-κB activation as well as catabolic gene expression. Interestingly, IGF-II did not significantly alter the phosphorylation states of ERK1/2 or Akt, which are kinases typically activated by IGF-I. Instead, it induced the activity of phospholipase C (PLC) and a PLC inhibitor blocked the inhibitory activity of IGF-II against IL-1β, suggesting that this activity is mediated through PLC. Furthermore, IGF-II increased cartilage matrix levels and decreased MMP13 protein expression in explanted human OA cartilage cultures in vitro. In the in vivo DMM model, intraarticular injection of lentiviral IGF-II led to enhanced cartilage matrix levels and decreased MMP13 protein expression, as well as reduced osteophyte formation and subchondral bone sclerosis. Therefore, our results suggest that IGF-II can promote cartilage integrity and halt knee joint destruction in OA.
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Affiliation(s)
- Tomoya Uchimura
- Program in Cellular, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111.,Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111
| | - Andrea T Foote
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111
| | - Eric L Smith
- Department of Orthopaedic Surgery, Tufts Medical Center, 800 Washington Street, Boston, Massachusetts, 02111
| | - Elizabeth G Matzkin
- Department of Orthopaedic Surgery, Tufts Medical Center, 800 Washington Street, Boston, Massachusetts, 02111
| | - Li Zeng
- Program in Cellular, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111.,Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, Massachusetts, 02111.,Department of Orthopaedic Surgery, Tufts Medical Center, 800 Washington Street, Boston, Massachusetts, 02111
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5
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The effect of interleukins 27 and 35 and their role on mediating the action of insulin Like Growth Factor -1 on the inflammation and blood flow of chronically inflamed rat knee joint. Cytokine 2016; 81:117-26. [DOI: 10.1016/j.cyto.2016.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 02/16/2016] [Accepted: 03/11/2016] [Indexed: 11/23/2022]
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6
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Asfour S, Travascio F, Elmasry S, de Rivero Vaccari JP. A computational analysis on the implications of age-related changes in the expression of cellular signals on the role of IGF-1 in intervertebral disc homeostasis. J Biomech 2014; 48:332-9. [PMID: 25488135 DOI: 10.1016/j.jbiomech.2014.11.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/21/2014] [Accepted: 11/18/2014] [Indexed: 01/07/2023]
Abstract
Insulin-like growth factor-1 (IGF-1) is a well-known anabolic agent in intervertebral discs (IVD), promoting both proteoglycan (PG) biosynthesis and cell proliferation. Accordingly, it is believed that IGF-1 plays a central role in IVD homeostasis. The IGF-mediated anabolic activity in IVD occurs when the growth factor, free from binding proteins (IGFBP), binds to IGF cell surface receptors (IGF-1R). Previous studies reported that, with aging, cellular expression of IGFBP increases, while that of IGF-1R decreases. Both changes in cellular signals are thought to be among the factors that are responsible for the age-related decline in IGF-mediated PG biosynthesis, which ultimately leads to disc degeneration. In this study, a computational model describing the role of IGF-1 in the homeostasis of IVD was deployed in a parametric analysis to investigate the effects of age-related changes in expression of IGF-1R and IGFBP on the IGF-mediated upregulation of PG biosynthesis and cellular proliferation. It was found that changes in the expression of IGF-1R and IGFBP mostly affected the nucleus pulposus, while in the most external disc regions (annulus fibrosus and cartilage endplates) the IVD homeostatic balance was unaltered. It was shown that a decrease of IGF-1R expression caused reduction of both PG levels and cell density in the tissue. In contrast, increase in IGFBP expression increased both PG and cell concentration, suggesting that such change in cellular signaling may be a plausible defense mechanism from age-related IVD degeneration.
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Affiliation(s)
- Shihab Asfour
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, United States
| | - Francesco Travascio
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, United States
| | - Shady Elmasry
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, United States
| | - Juan Pablo de Rivero Vaccari
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami, Miami, FL, United States
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Travascio F, Eltoukhy M, Cami S, Asfour S. Altered mechano-chemical environment in hip articular cartilage: effect of obesity. Biomech Model Mechanobiol 2013; 13:945-59. [PMID: 24352367 DOI: 10.1007/s10237-013-0545-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/10/2013] [Indexed: 11/28/2022]
Abstract
The production of extracellular matrix (ECM) components of articular cartilage is regulated, among other factors, by an intercellular signaling mechanism mediated by the interaction of cell surface receptors (CSR) with insulin-like growth factor-1 (IGF-1). In ECM, the presence of binding proteins (IGFBP) hinders IGF-1 delivery to CSR. It has been reported that levels of IGF-1 and IGFBP in obese population are, respectively, lower and higher than those found in normal population. In this study, an experimental-numerical approach was adopted to quantify the effect of this metabolic alteration found in obese population on the homeostasis of femoral hip cartilage. A new computational model, based on the mechano-electrochemical mixture theory, was developed to describe competitive binding kinetics of IGF-1 with IGFBP and CSR, and associated glycosaminoglycan (GAG) biosynthesis. Moreover, a gait analysis was carried out on obese and normal subjects to experimentally characterize mechanical loads on hip cartilage during walking. This information was deployed into the model to account for effects of physiologically relevant tissue deformation on GAG production in ECM. Numerical simulations were performed to compare GAG biosynthesis in femoral hip cartilage of normal and obese subjects. Results indicated that the lower ratio of IGF-1 to IGFBP found in obese population reduces cartilage GAG concentration up to 18 % when compared to normal population. Moreover, moderate physical activity, such as walking, has a modest beneficial effect on GAG production. The findings of this study suggest that IGF-1/IGFBP metabolic unbalance should be accounted for when considering the association of obesity with hip osteoarthritis.
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Affiliation(s)
- Francesco Travascio
- Biomechanics Research Laboratory, Department of Industrial Engineering, College of Engineering, University of Miami, 1251 Memorial Drive, MEB 268, Coral Gables, FL, 33124-0621, USA
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8
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Transport and binding of tumor necrosis factor-α in articular cartilage depend on its quaternary structure. Arch Biochem Biophys 2013; 540:1-8. [PMID: 24135706 DOI: 10.1016/j.abb.2013.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/16/2013] [Accepted: 10/03/2013] [Indexed: 01/05/2023]
Abstract
The effect of tumor necrosis factor-α (TNFα) on cartilage matrix degradation is mediated by its transport and binding within the extracellular matrix (ECM) of the tissue, which mediates availability to cell receptors. Since the bioactive form of TNFα is a homotrimer of monomeric subunits, conversion between trimeric and monomeric forms during intratissue transport may affect binding to ECM and, thereby, bioactivity within cartilage. We studied the transport and binding of TNFα in cartilage, considering the quaternary structure of this cytokine. Competitive binding assays showed significant binding of TNFα in cartilage tissue, leading to an enhanced uptake. However, studies in which TNFα was cross-linked to remain in the trimeric form revealed that the binding of trimeric TNFα was negligible. Thus, binding of TNFα to ECM was associated with the monomeric form. Binding of TNFα was not disrupted by pre-treating cartilage tissue with trypsin, which removes proteoglycans and glycoproteins but leaves the collagen network intact. Therefore, proteoglycan loss during osteoarthritis should only alter the passive diffusion of TNFα but not its binding interaction with the remaining matrix. Our results suggest that matrix binding and trimer-monomer conversion of TNFα both play crucial roles in regulating the accessibility of bioactive TNFα within cartilage.
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9
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Santo VE, Gomes ME, Mano JF, Reis RL. Controlled release strategies for bone, cartilage, and osteochondral engineering--Part I: recapitulation of native tissue healing and variables for the design of delivery systems. TISSUE ENGINEERING. PART B, REVIEWS 2013; 19:308-26. [PMID: 23268651 PMCID: PMC3690094 DOI: 10.1089/ten.teb.2012.0138] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 12/11/2012] [Indexed: 12/12/2022]
Abstract
The potential of growth factors to stimulate tissue healing through the enhancement of cell proliferation, migration, and differentiation is undeniable. However, critical parameters on the design of adequate carriers, such as uncontrolled spatiotemporal presence of bioactive factors, inadequate release profiles, and supraphysiological dosages of growth factors, have impaired the translation of these systems onto clinical practice. This review describes the healing cascades for bone, cartilage, and osteochondral interface, highlighting the role of specific growth factors for triggering the reactions leading to tissue regeneration. Critical criteria on the design of carriers for controlled release of bioactive factors are also reported, focusing on the need to provide a spatiotemporal control over the delivery and presentation of these molecules.
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Affiliation(s)
- Vítor E. Santo
- 3Bs Research Group—Biomaterials, Biodegradables, and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Manuela E. Gomes
- 3Bs Research Group—Biomaterials, Biodegradables, and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - João F. Mano
- 3Bs Research Group—Biomaterials, Biodegradables, and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rui L. Reis
- 3Bs Research Group—Biomaterials, Biodegradables, and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal
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10
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Modeling the Insulin-Like Growth Factor System in Articular Cartilage. PLoS One 2013; 8:e66870. [PMID: 23840540 PMCID: PMC3694163 DOI: 10.1371/journal.pone.0066870] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 05/11/2013] [Indexed: 11/23/2022] Open
Abstract
IGF signaling is involved in cell proliferation, differentiation and apoptosis in a wide range of tissues, both normal and diseased, and so IGF-IR has been the focus of intense interest as a promising drug target. In this computational study on cartilage, we focus on two questions: (i) what are the key factors influencing IGF-IR complex formation, and (ii) how might cells regulate IGF-IR complex formation? We develop a reaction-diffusion computational model of the IGF system involving twenty three parameters. A series of parametric and sensitivity studies are used to identify the key factors influencing IGF signaling. From the model we predict the free IGF and IGF-IR complex concentrations throughout the tissue. We estimate the degradation half-lives of free IGF-I and IGFBPs in normal cartilage to be 20 and 100 mins respectively, and conclude that regulation of the IGF half-life, either directly or indirectly via extracellular matrix IGF-BP protease concentrations, are two critical factors governing the IGF-IR complex formation in the cartilage. Further we find that cellular regulation of IGF-II production, the IGF-IIR concentration and its clearance rate, all significantly influence IGF signaling. It is likely that negative feedback processes via regulation of these factors tune IGF signaling within a tissue, which may help explain the recent failures of single target drug therapies aimed at modifying IGF signaling.
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11
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Byun S, Sinskey YL, Lu YCS, Ort T, Kavalkovich K, Sivakumar P, Hunziker EB, Frank EH, Grodzinsky AJ. Transport of anti-IL-6 antigen binding fragments into cartilage and the effects of injury. Arch Biochem Biophys 2013; 532:15-22. [PMID: 23333631 DOI: 10.1016/j.abb.2012.12.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 12/05/2012] [Accepted: 12/19/2012] [Indexed: 12/15/2022]
Abstract
The efficacy of biological therapeutics against cartilage degradation in osteoarthritis is restricted by the limited transport of macromolecules through the dense, avascular extracellular matrix. The availability of biologics to cell surface and matrix targets is limited by steric hindrance of the matrix, and the microstructure of matrix itself can be dramatically altered by joint injury and the subsequent inflammatory response. We studied the transport into cartilage of a 48 kDa anti-IL-6 antigen binding fragment (Fab) using an in vitro model of joint injury to quantify the transport of Fab fragments into normal and mechanically injured cartilage. The anti-IL-6 Fab was able to diffuse throughout the depth of the tissue, suggesting that Fab fragments can have the desired property of achieving local delivery to targets within cartilage, unlike full-sized antibodies which are too large to penetrate beyond the cartilage surface. Uptake of the anti-IL-6 Fab was significantly increased following mechanical injury, and an additional increase in uptake was observed in response to combined treatment with TNFα and mechanical injury, a model used to mimic the inflammatory response following joint injury. These results suggest that joint trauma leading to cartilage degradation can further alter the transport of such therapeutics and similar-sized macromolecules.
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Affiliation(s)
- Sangwon Byun
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
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12
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Huang CY, Travascio F, Gu WY. Quantitative analysis of exogenous IGF-1 administration of intervertebral disc through intradiscal injection. J Biomech 2012; 45:1149-55. [PMID: 22365501 DOI: 10.1016/j.jbiomech.2012.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 12/22/2011] [Accepted: 02/02/2012] [Indexed: 11/28/2022]
Abstract
Exogenous administration of IGF-1 has been proposed as a therapy for disc degeneration. The objectives of this study were to develop a numerical model for quantitatively analysing exogenous administration of IGF-1 into the intervertebral disc (IVD) via intradiscal injection and to investigate the effects of IGF-1 administration on distribution of glucose and oxygen in the IVD. In this study, the reversible binding reaction between IGF-1 and IGF binding proteins was incorporated into the mechano-electrochemical mixture model. The model was used to numerically analyse transport of IGF-1, glucose, oxygen and lactate in the IVD after IGF-1 administration. The enhancement of IGF-1 on lactate production was also taken into account in the theoretical model. The numerical analyses using finite element method demonstrated that the binding reactions significantly affect the time-dependent distribution of IGF-1 in the IVD. It was found that the region affected by IGF-1 was smaller and the duration of the therapeutic IGF-1 level was longer in the degenerated disc with a higher concentration of IGF binding proteins. It was also found that the IGF-1 injection can reduce glucose concentration and increase lactate accumulation (i.e., lower pH) in the IVD and these influences were regulated by the IGF-1 binding reactions. This study indicated the complexity of intradiscal administration of growth factors, which needs to be fully analysed in order to achieve a successful outcome. The new theoretical model developed in this study can serve as a powerful tool in analysing and designing the optimal treatments of growth factors for disc degeneration.
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Affiliation(s)
- C-Y Huang
- Stem Cell and Mechanobiology Lab, Dept of Biomedical Engineering, University of Miami, Coral Gables, Florida 33146, USA
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13
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Adhikari AS, Mekhdjian AH, Dunn AR. Strain tunes proteolytic degradation and diffusive transport in fibrin networks. Biomacromolecules 2012; 13:499-506. [PMID: 22185486 PMCID: PMC3737078 DOI: 10.1021/bm2015619] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proteolytic degradation of fibrin, the major structural component in blood clots, is critical both during normal wound healing and in the treatment of ischemic stroke and myocardial infarction. Fibrin-containing clots experience substantial strain due to platelet contraction, fluid shear, and mechanical stress at the wound site. However, little is understood about how mechanical forces may influence fibrin dissolution. We used video microscopy to image strained fibrin clots as they were degraded by plasmin, a major fibrinolytic enzyme. Applied strain causes up to 10-fold reduction in the rate of fibrin degradation. Analysis of our data supports a quantitative model in which the decrease in fibrin proteolysis rates with strain stems from slower transport of plasmin into the clot. We performed fluorescence recovery after photobleaching (FRAP) measurements to further probe the effect of strain on diffusive transport. We find that diffusivity perpendicular to the strain axis decreases with increasing strain, while diffusivity along the strain axis remains unchanged. Our results suggest that the properties of the fibrin network have evolved to protect mechanically loaded fibrin from degradation, consistent with its function in wound healing. The pronounced effect of strain upon diffusivity and proteolytic susceptibility within fibrin networks offers a potentially useful means of guiding cell growth and morphology in fibrin-based biomaterials.
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Affiliation(s)
- Arjun S. Adhikari
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Armen H. Mekhdjian
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Alexander R. Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
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14
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Shkilnyy A, Proulx P, Sharp J, Lepage M, Vermette P. Diffusion of rhodamine B and bovine serum albumin in fibrin gels seeded with primary endothelial cells. Colloids Surf B Biointerfaces 2012; 93:202-7. [PMID: 22293601 DOI: 10.1016/j.colsurfb.2012.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 12/16/2011] [Accepted: 01/04/2012] [Indexed: 11/19/2022]
Abstract
Scaffolds with adequate mass transport properties are needed in many tissue engineering applications. Fibrin is considered a good biological material to fabricate such scaffolds. However, very little is known about mass transport in fibrin. Therefore, a method based on the analysis of fluorescence intensity for measuring the apparent diffusion coefficient of rhodamine B and fluorescein-labelled bovine serum albumin (FITC-BSA) is described. The experiments are performed in fibrin gels with and without human umbilical vein endothelial cells (HUVEC). The apparent diffusion coefficients of rhodamine B and FITC-BSA in fibrin (fibrinogen concentration of 4 mg/mL) with different cell densities are reported. A LIVE/DEAD(®) assay is performed to confirm the viability of HUVEC seeded at high densities. Diffusion coefficients for rhodamine B remain more or less constant up to 5×10(5) cells/mL and correlate well with literature values measured by other methods in water systems. This indicates that the presence of HUVEC in the fibrin gels (up to 5×10(5) cells/mL) has almost no effect on the diffusion coefficients. Higher cell densities (>5×10(5) cells/mL) result in a decrease of the diffusion coefficients. Diffusion coefficients of rhodamine B and FITC-BSA obtained by this method agree with diffusion coefficients in water predicted by the Stokes-Einstein equation. The experimental design used in this study can be applied to measure diffusion coefficients in different types of gels seeded or not with living cells.
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Affiliation(s)
- Andriy Shkilnyy
- Laboratoire de bio-ingénierie et de biophysique de l'Université de Sherbrooke, Department of Chemical and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
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15
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ZHANG LIHAI, GARDINER BRUCES, SMITH DAVIDW, PIVONKA PETER, GRODZINSKY ALANJ. IGF UPTAKE WITH COMPETITIVE BINDING IN ARTICULAR CARTILAGE. J BIOL SYST 2011. [DOI: 10.1142/s0218339008002575] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Experiments on the transport of radiolabeled Insulin-like Growth Factors (IGF-I and -II) into bovine articular cartilage show differential uptake depending on the relative proportion of IGF-I and -II. In this study, we present a mathematical model describing both the transport and competition of IGF-I and -II for binding sites represented by two functional groupings of IGF binding proteins (IGFBPs). The first grouping has approximately similar binding affinity to both IGF-I and -II (i.e. IGFBPs 1–5), whereas the second group has significantly higher binding preference for IGF-II compared to IGF-I (i.e. IGFBP-6). Using nonlinear least squares, it is shown that the experimental equilibrium competitive binding results can be described using a reversible Langmuir sorption isotherm involving two dominant IGFBP functional groups.After coupling the sorption model with a poromechanical continuum model, parametric studies are carried out to investigate the effect of model changes including IGF boundary conditions and the ratios of the two IGFBP functional groups. The results show that ignoring competitive binding leads to a significant overestimation of total IGF-I uptake, but an underestimation the rate of "free" (physiologically active) IGF-I within the cartilage. An increase of first group of IGFBPs (i.e. IGFBPs 1–5) as has been reported for osteoarthritis, is observed to hinder the bioavailability of free IGF-I in cartilage, even though the total IGF-I uptake is enhanced. Furthermore, the combination of dynamic compression and competitive binding is seen to enhance the IGF-I uptake within cartilage, but this enhancement is overestimated if competitive binding is neglected.
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Affiliation(s)
- LIHAI ZHANG
- Department of Civil and Environmental Engineering, The University of Melbourne, VIC 3010, Australia
| | - BRUCE S. GARDINER
- Department of Civil and Environmental Engineering, The University of Melbourne, VIC 3010, Australia
| | - DAVID W. SMITH
- Department of Civil and Environmental Engineering, The University of Melbourne, VIC 3010, Australia
| | - PETER PIVONKA
- Department of Civil and Environmental Engineering, The University of Melbourne, VIC 3010, Australia
| | - ALAN J. GRODZINSKY
- Center for Biomedical Engineering, Department of Electrical Engineering and Computer Science, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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16
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Miller RE, Grodzinsky AJ, Cummings K, Plaas AHK, Cole AA, Lee RT, Patwari P. Intraarticular injection of heparin-binding insulin-like growth factor 1 sustains delivery of insulin-like growth factor 1 to cartilage through binding to chondroitin sulfate. ACTA ACUST UNITED AC 2011; 62:3686-94. [PMID: 20722014 DOI: 10.1002/art.27709] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Insulin-like growth factor 1 (IGF-1) stimulates cartilage repair but is not a practical therapy due to its short half-life. We have previously modified IGF-1 by adding a heparin-binding domain and have shown that this fusion protein (HB-IGF-1) stimulates sustained proteoglycan synthesis in cartilage. This study was undertaken to examine the mechanism by which HB-IGF-1 is retained in cartilage and to test whether HB-IGF-1 provides sustained growth factor delivery to cartilage in vivo and to human cartilage explants. METHODS Retention of HB-IGF-1 and IGF-1 was analyzed by Western blotting. The necessity of heparan sulfate (HS) or chondroitin sulfate (CS) glycosaminoglycans (GAGs) for binding was tested using enzymatic removal and cells with genetic deficiency of HS. Binding affinities of HB-IGF-1 and IGF-1 proteins for isolated GAGs were examined by surface plasmon resonance and enzyme-linked immunosorbent assay. RESULTS In cartilage explants, chondroitinase treatment decreased binding of HB-IGF-1, whereas heparitinase had no effect. Furthermore, HS was not necessary for HB-IGF-1 retention on cell monolayers. Binding assays showed that HB-IGF-1 bound both CS and HS, whereas IGF-1 did not bind either. After intraarticular injection in rat knees, HB-IGF-1 was retained in articular and meniscal cartilage, but not in tendon, consistent with enhanced delivery to CS-rich cartilage. Finally, HB-IGF-1 was retained in human cartilage explants but IGF-1 was not. CONCLUSION Our findings indicate that after intraarticular injection in rats, HB-IGF-1 is specifically retained in cartilage through its high abundance of CS. Modification of growth factors with heparin-binding domains may be a new strategy for sustained and specific local delivery to cartilage.
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Affiliation(s)
- Rachel E Miller
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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17
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Galasso O, De Gori M, Nocera A, Brunetti A, Gasparini G. Regulatory Functions of Insulin-like Growth Factor Binding Proteins in Osteoarthritis. Int J Immunopathol Pharmacol 2011; 24:55-9. [DOI: 10.1177/03946320110241s211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Insulin-like growth factor binding proteins (IGFBPs) are a group of secreted proteins, which bind to IGF-I (and IGF-II) with high affinity and modulate the biological actions of IGFs. Abundant evidence points the importance of the IGF-I/IGFBP system on both cell growth and differentiation. A role for the IGF-I/IGFBP system in the regulation of normal human cartilage has been previously reported. In this context, recent studies suggest an emerging role for IGFBPs in the failure of cartilage during osteoarthritis (OA). Indeed, increased IGFBP levels have been reported in both the articular cartilage and synovial fluid from patients with OA. Overexpression of IGFBPs, by altering the bioavailability and function of IGFs, is likely to deliver IGFs-independent signals for chondrocyte survival. This, at least in part, might explain the degenerative changes of the cartilage in OA. Further studies are necessary to clarify the mechanisms that cause the overexpression of IGFBPs in patients with OA. Advances in our understanding of the relationship between osteoarthritis and the IGF-I/IGFBP system may lead to new treatment strategies for this degenerative disease.
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Affiliation(s)
- O. Galasso
- Department of Orthopaedic and Trauma Surgery, University “Magna Græcia”of Catanzaro, V.le Europa (Loc. Germaneto), 88100 Catanzaro, Italy
| | - M. De Gori
- Department of Orthopaedic and Trauma Surgery, University “Magna Græcia”of Catanzaro, V.le Europa (Loc. Germaneto), 88100 Catanzaro, Italy
| | - A. Nocera
- Department of Experimental and Clinical Medicine, University “Magna Græcia”of Catanzaro, V.le Europa (Loc. Germaneto), 88100 Catanzaro, Italy
| | - A. Brunetti
- Department of Experimental and Clinical Medicine, University “Magna Græcia”of Catanzaro, V.le Europa (Loc. Germaneto), 88100 Catanzaro, Italy
| | - G. Gasparini
- Department of Orthopaedic and Trauma Surgery, University “Magna Græcia”of Catanzaro, V.le Europa (Loc. Germaneto), 88100 Catanzaro, Italy
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18
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Simultaneous measurement of anisotropic solute diffusivity and binding reaction rates in biological tissues by FRAP. Ann Biomed Eng 2010; 39:53-65. [PMID: 20686922 DOI: 10.1007/s10439-010-0138-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 07/28/2010] [Indexed: 10/19/2022]
Abstract
Several solutes (e.g., growth factors, cationic solutes, etc.) can reversibly bind to the extracellular matrix (ECM) of biological tissues. Binding interactions have significant implications on transport of such solutes through the ECM. In order to fully delineate transport phenomena in biological tissues, knowledge of binding kinetics is crucial. In this study, a new method for the simultaneous determination of solute anisotropic diffusivity and binding reaction rates was presented. The new technique was solely based on Fourier analysis of fluorescence recovery after photobleaching (FRAP) images. Computer-simulated FRAP tests were used to assess the sensitivity and the robustness of the method to experimental parameters, such as anisotropic solute diffusivity and rates of binding reaction. The new method was applied to the determination of diffusivity and binding rates of 5-dodecanoylaminofluorescein (DAF) in bovine coccygeal annulus fibrosus (AF). Our findings indicate that DAF reversibly binds to the ECM of AF. In addition, it was found that DAF diffusion in AF is anisotropic. The results were in agreement with those reported in previous studies. This study provides a new tool for the simultaneous determination of solute anisotropic diffusion tensor and rates of binding reaction that can be used to investigate diffusive-reactive transport in biological tissues and tissue engineered constructs.
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19
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Byun S, Tortorella MD, Malfait AM, Fok K, Frank EH, Grodzinsky AJ. Transport and equilibrium uptake of a peptide inhibitor of PACE4 into articular cartilage is dominated by electrostatic interactions. Arch Biochem Biophys 2010; 499:32-9. [PMID: 20447377 DOI: 10.1016/j.abb.2010.04.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2009] [Revised: 04/22/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
Abstract
The availability of therapeutic molecules to targets within cartilage depends on transport through the avascular matrix. We studied equilibrium partitioning and non-equilibrium transport into cartilage of Pf-pep, a 760 Da positively charged peptide inhibitor of the proprotein convertase PACE4. Competitive binding measurements revealed negligible binding of Pf-pep to sites within cartilage. Uptake of Pf-pep depended on glycosaminoglycan charge density, and was consistent with predictions of Donnan equilibrium given the known charge of Pf-pep. In separate transport experiments, the diffusivity of Pf-pep in cartilage was measured to be approximately 1 x 10(-6) cm(2)/s, close to other similarly-sized non-binding solutes. These results suggest that small positively charged therapeutics will have a higher concentration within cartilage than in the surrounding synovial fluid, a desired property for local delivery; however, such therapeutics may rapidly diffuse out of cartilage unless there is additional specific binding to intra-tissue substrates that can maintain enhanced intra-tissue concentration for local delivery.
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Affiliation(s)
- Sangwon Byun
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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20
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Cartilage engineering from mesenchymal stem cells. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2010; 123:163-200. [PMID: 20535603 DOI: 10.1007/10_2010_67] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mesenchymal progenitor cells known as multipotent mesenchymal stromal cells or mesenchymal stem cells (MSC) have been isolated from various tissues. Since they are able to differentiate along the mesenchymal lineages of cartilage and bone, they are regarded as promising sources for the treatment of skeletal defects. Tissue regeneration in the adult organism and in vitro engineering of tissues is hypothesized to follow the principles of embryogenesis. The embryonic development of the skeleton has been studied extensively with respect to the regulatory mechanisms governing morphogenesis, differentiation, and tissue formation. Various concepts have been designed for engineering tissues in vitro based on these developmental principles, most of them involving regulatory molecules such as growth factors or cytokines known to be the key regulators in developmental processes. Growth factors most commonly used for in vitro cultivation of cartilage tissue belong to the fibroblast growth factor (FGF) family, the transforming growth factor-beta (TGF-β) super-family, and the insulin-like growth factor (IGF) family. In this chapter, in vivo actions of members of these growth factors described in the literature are compared with in vitro concepts of cartilage engineering making use of these growth factors.
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21
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Sun T, Hunziker EB, Morales TI. Subcellular distribution of the insulin-like growth factor (IGF) binding proteins (IGFBPs) 2 and 3 in articular chondrocytes. J Orthop Res 2008; 26:1421-7. [PMID: 18418889 DOI: 10.1002/jor.20660] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The insulin-like growth factor (IGF) is a major anabolic regulator in articular cartilage. The IGF-binding proteins (IGFBPs) are increased during osteoarthritis (OA), but the function of the later proteins remains unknown. In general, the IGFBPs are pluripotential effectors capable of IGF regulation and of acting on their own to control key cell functions, including survival and proliferation. The independent functions are often associated with their cell location, and therefore this study explores the distribution of IGFBP-2 and IGFBP-3 in articular chondrocytes. Immunohistochemistry was used to localize IGFBP-2 in normal human articular cartilage. Bovine chondrocytes were used for subcellular fractionation (hypotonic cell lysis) under nonreducing conditions and nuclear purification (centrifugation on sucrose cushions). Cell fraction markers and IGFBPs were assayed in the subcellular fractions by Western immunoblot. The IHC results showed association of IGFBP-2 with chondrocytes, but not with the nuclei. Subcellular fractionation of isolated chondrocytes yielded intact nuclei as assessed at the light microscopic level; the nuclear marker histone H1 was exclusively associated with this fraction. More than 90% of the cytoplasmic marker GAPDH and all the detectable IGFBP-2 were in the cytoplasmic fraction. Immunoreactive IGFBP-3 was found in the cytoplasmic and peri-nuclear/nuclear fractions. Chondrocytes contain intracellular IGFBP-2 and IGFBP-3 but only IGFBP-3 is associated with nuclei. This suggests the hypothesis that the actions of these IGFBPs in articular cartilage extend beyond the classic modulation of IGF receptor action.
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Affiliation(s)
- Tiezheng Sun
- Department of Orthopaedic Surgery, The Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114, USA
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22
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Wescoe KE, Schugar RC, Chu CR, Deasy BM. The Role of the Biochemical and Biophysical Environment in Chondrogenic Stem Cell Differentiation Assays and Cartilage Tissue Engineering. Cell Biochem Biophys 2008; 52:85-102. [DOI: 10.1007/s12013-008-9029-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2008] [Indexed: 01/13/2023]
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23
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Morales T. The quantitative and functional relation between insulin-like growth factor-I (IGF) and IGF-binding proteins during human osteoarthritis. J Orthop Res 2008; 26:465-74. [PMID: 18050312 PMCID: PMC2988493 DOI: 10.1002/jor.20549] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A previous hypothesis stated that during osteoarthritis (OA) increased insulin-like growth factor (IGF) binding proteins (IGFBPs) sequester IGFs and limit their access to the cell. The objective of this article was to test this by: (1) quantifying IGF and IGFBP-3 as well as their ratios in human OA cartilages, and (2) measuring the metabolic responses of diseased cartilage to IGF-I and its IGFBP-insensitive analogs. Knee or hip OA cartilages were staged for OA by histology. Cartilage slices were either extracted for assays of IGF proteins, or maintained intact as organ cultures. Proteoglycan (PG) metabolism +/- IGFs was measured by use of the (35)S-sulfate precursor. IGFBP-3 (ng/mg protein) was weakly correlated with OA score by regression analysis (R(2) = 0.122; p = 0.040; n = 35). IGF-I (ng/mg protein) was constant across all OA groups (ANOVA; p = .428, n = 18) and the IGF-I/IGFBP-3 ratios were > 1 in most samples. All OA cartilages responded to hrIGF-I by increasing PG synthesis [average 2.29-fold +/- 0.55 (+/-SD) at saturation, n = 12] irrespective of OA score. The des (1-3) IGF-I analog (which lacks the three N-terminal amino acids) had similar maximal effects (average 2.23-fold stimulation +/- 0.71, n = 10), but it was more effective in two out of three samples at suboptimal doses. The effect of hrIGF-I, des (1-3) IGF-I, or the B-chain analog on degradation was minimal. In summary, catabolism was insensitive to IGF-I, and this was probably not due to IGFBPs. By contrast, IGF-I exerted a robust stimulation of anabolism at sufficiently high doses, even though IGFBPs could tone down the ligand effect at low doses.
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Affiliation(s)
- T.I. Morales
- Harvard Medical School and Massachusetts General Hospital, Boston, MA. USA
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24
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Tokunou T, Miller R, Patwari P, Davis ME, Segers VFM, Grodzinsky AJ, Lee RT. Engineering insulin-like growth factor-1 for local delivery. FASEB J 2008; 22:1886-93. [PMID: 18285400 DOI: 10.1096/fj.07-100925] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a small protein that promotes cell survival and growth, often acting over long distances. Although for decades IGF-1 has been considered to have therapeutic potential, systemic side effects of IGF-1 are significant, and local delivery of IGF-1 for tissue repair has been a long-standing challenge. In this study, we designed and purified a novel protein, heparin-binding IGF-1 (Xp-HB-IGF-1), which is a fusion protein of native IGF-1 with the heparin-binding domain of heparin-binding epidermal growth factor-like growth factor. Xp-HB-IGF-1 bound selectively to heparin as well as the cell surfaces of 3T3 fibroblasts, neonatal cardiac myocytes and differentiating ES cells. Xp-HB-IGF-1 activated the IGF-1 receptor and Akt with identical kinetics and dose response, indicating no compromise of biological activity due to the heparin-binding domain. Because cartilage is a proteoglycan-rich environment and IGF-1 is a known stimulus for chondrocyte biosynthesis, we then studied the effectiveness of Xp-HB-IGF-1 in cartilage. Xp-HB-IGF-1 was selectively retained by cartilage explants and led to sustained chondrocyte proteoglycan biosynthesis compared to IGF-1. These data show that the strategy of engineering a "long-distance" growth factor like IGF-1 for local delivery may be useful for tissue repair and minimizing systemic effects.
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Affiliation(s)
- Tomotake Tokunou
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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25
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Hunziker EB, Kapfinger E, Martin J, Buckwalter J, Morales TI. Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) is closely associated with the chondrocyte nucleus in human articular cartilage. Osteoarthritis Cartilage 2008; 16:185-94. [PMID: 17693100 PMCID: PMC2364636 DOI: 10.1016/j.joca.2007.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 06/06/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Insulin-like growth factor-I (IGF-I) is critically involved in the control of cartilage matrix metabolism. It is well known that IGF-binding protein-3 (IGFBP-3) is increased during osteoarthritis (OA), but its function(s) is not known. In other cells, IGFBP-3 can regulate IGF-I action in the extracellular environment and can also act independently inside the cell; this includes transcriptional gene control in the nucleus. These studies were undertaken to localize IGFBP-3 in human articular cartilage, particularly within cells. DESIGN Cartilage was dissected from human femoral heads derived from arthroplasty for OA, and OA grade assessed by histology. Tissue slices were further characterized by extraction and assay of IGFBPs by IGF ligand blot (LB) and by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry (IHC) for IGF-I and IGFBP-3 was performed on cartilage from donors with mild, moderate and severe OA. Indirect fluorescence and immunogold-labeling IHC studies were included. RESULTS LBs of chondrocyte lysates showed a strong signal for IGFBP-3. IHC of femoral cartilage sections at all OA stages showed IGF-I and IGFBP-3 matrix stain particularly in the top zones, and closely associated with most cells. A prominent perinuclear/nuclear IGFBP-3 signal was seen. Controls using non-immune sera or antigen-blocked antibody showed negative or strongly reduced stain. In frozen sections of human ankle cartilage, immunofluorescent IGFBP-3 stain co-localized with the nuclear 4',6-diamidino-2-phenyl indole (DAPI) stain in greater than 90% of the cells. Immunogold IHC of thin sections and transmission electron immunogold microscopy of ultra-thin sections showed distinct intra-nuclear staining. CONCLUSIONS IGFBP-3 in human cartilage is located in the matrix and within chondrocytes in the cytoplasm and nuclei. This new finding indicates that the range of IGFBP-3 actions in articular cartilage is likely to include IGF-independent roles and opens the door to studies of its nuclear actions, including the possible regulation of hormone receptors or transcriptional complexes to control gene action.
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Affiliation(s)
- E B Hunziker
- ITI Research Institute for Dental and Skeletal Biology, Bern, Switzerland
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26
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Nakajima M, Wakitani S, Harada Y, Tanigami A, Tomita N. In vivo mechanical condition plays an important role for appearance of cartilage tissue in ES cell transplanted joint. J Orthop Res 2008; 26:10-7. [PMID: 17676607 DOI: 10.1002/jor.20462] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective of this study was to evaluate the effects of the mechanical environment on the formation of cartilage tissue in transplanted embryonic stem (ES) cells. Full-thickness osteochondral defects were created on the patella groove of SD rats, and ES cells (CCE ES cells obtained from 129/Sv/Ev mice and Green ES FM260 ES cells obtained from 129SV [D3] - Tg [NCAG-EGFP] CZ-001-FM260Osb mice) were transplanted into the defects embedded in collagen gel. The animals were randomly divided into either the joint-free group (JF group) or the joint-immobilized group (JI group) for 3 weeks after a week postoperatively. The results showed that cartilage-like tissue formed in the defects of the JF group whereas large teratomatous masses developed in the defects of the JI group. Some parts of the cartilage-like tissue and the teratomatous masses were positively stained with immunostain for GFP when the Green ES FM260 ES cells were transplanted. It is suggested that the environment plays an important role for ES cells in the process of repairing cartilage tissue in vivo.
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Affiliation(s)
- Masaaki Nakajima
- International Innovation Center, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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27
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Yoon DM, Fisher JP. Chondrocyte signaling and artificial matrices for articular cartilage engineering. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 585:67-86. [PMID: 17120777 DOI: 10.1007/978-0-387-34133-0_5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Chondrocytes depend on their environment to aid in their expression of appropriate proteins. It has been found that the interaction of integrin receptors with chondrocytes effects the production of extracellular molecules such as type II collagen and aggrecan. Additionally, the presence of growth factors such as IGF-1, TGF-beta1 and BMP-7 induce various signaling pathways that also aid in transducing phenotypic expressions by chondrocytes. Natural and synthetic polymers have been used to act as a scaffold for chondrocytes. The production of extracellular matrix proteins by chondrocytes has been studied. As tissue engineers, it is advantageous to explore the possibility of how altering biomaterial properties affect the signaling cascades by activation of receptors and transduction through the cytoplasm. This vital information will be able to aid in the future of engineering an appropriate biomaterial that can incorporate chondrocytes to act as a scaffold for articular cartilage.
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Affiliation(s)
- Diana M Yoon
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD, USA
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28
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Lima EG, Bian L, Ng KW, Mauck RL, Byers BA, Tuan RS, Ateshian GA, Hung CT. The beneficial effect of delayed compressive loading on tissue-engineered cartilage constructs cultured with TGF-beta3. Osteoarthritis Cartilage 2007; 15:1025-33. [PMID: 17498976 PMCID: PMC2724596 DOI: 10.1016/j.joca.2007.03.008] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Accepted: 03/11/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether the functional properties of tissue-engineered constructs cultured in a chemically-defined medium supplemented briefly with TGF-beta3 can be enhanced with the application of dynamic deformational loading. METHODS Primary immature bovine cells (2-3 months old) were encapsulated in agarose hydrogel (2%, 30 x 10(6)cells/ml) and cultured in chemically-defined medium supplemented for the first 2 weeks with transforming growth factor beta 3 (TGF-beta3) (10 microg/ml). Physiologic deformational loading (1 Hz, 3 h/day, 10% unconfined deformation initially and tapering to 2% peak-to-peak deformation by day 42) was applied either concurrent with or after the period of TGF-beta3 supplementation. Mechanical and biochemical properties were evaluated up to day 56. RESULTS Dynamic deformational loading applied concurrently with TGF-beta3 supplementation yielded significantly lower (-90%) overall mechanical properties when compared to free-swelling controls. In contrast, the same loading protocol applied after the discontinuation of the growth factor resulted in significantly increased (+10%) overall mechanical properties relative to free-swelling controls. Equilibrium modulus values reach 1306+/-79 kPa and glycosaminoglycan levels reach 8.7+/-1.6% w.w. during this 8-week period and are similar to host cartilage properties (994+/-280 kPa, 6.3+/-0.9% w.w.). CONCLUSIONS An optimal strategy for the functional tissue engineering of articular cartilage, particularly to accelerate construct development, may incorporate sequential application of different growth factors and applied deformational loading.
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Affiliation(s)
- E G Lima
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Avenue, New York, NY 10027, USA
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29
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Gardiner B, Smith D, Pivonka P, Grodzinsky A, Frank E, Zhang L. Solute transport in cartilage undergoing cyclic deformation. Comput Methods Biomech Biomed Engin 2007; 10:265-78. [PMID: 17671860 DOI: 10.1080/10255840701309163] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
There are no blood vessels in cartilage to transport nutrients and growth factors to chondrocytes dispersed throughout the cartilage matrix. Insulin-like growth factor-I (IGF-I) is a large molecule with an important role in cartilage growth and metabolism, however, it first must reach the chondrocytes to exert its effect. While diffusion of IGF-I through cartilage is possible, it has been speculated that cyclic loading can enhance the rate of solute transport within cartilage. To better understand this process, here a one-dimensional axisymmetric mathematical model is developed to examine the transport of solutes through a cylindrical plug of cartilage undergoing cyclic axial deformation in the range of 10(-3) -1 Hz. This study has revealed the role of timescales in interpreting transport results in cartilage. It is shown that dynamic strains can either enhance or inhibit IGF-I transport at small timescales (< 20 min after onset of loading), depending on loading frequency. However, on longer timescales it is found that dynamic loading has negligible effect on IGF-I transport. Most importantly, in all cases examined the steady state IGF-I concentration did not exceed the fixed boundary value, in contrast to the predictions of Mauk et al. (2003).
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Affiliation(s)
- Bruce Gardiner
- Department of Civil and Environmental Engineering, Centre for Biomedical Engineering, The University of Melbourne, Melbourne, Vic., Australia.
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30
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Nauman JV, Campbell PG, Lanni F, Anderson JL. Diffusion of insulin-like growth factor-I and ribonuclease through fibrin gels. Biophys J 2007; 92:4444-50. [PMID: 17400703 PMCID: PMC1877763 DOI: 10.1529/biophysj.106.102699] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A fluorescence-based method for simultaneously determining the diffusion coefficients of two proteins is described, and the diffusion coefficient of insulin-like growth factor (IGF-I) and ribonuclease (RNase) in a 0.27% fibrin hydrogel is reported. The method is based on two-color imaging of the relaxation of the protein concentration field with time and comparing the results with a transport model. The gel is confined in a thin (200 microm) capillary and the protein is labeled with a fluorescent dye. The experimentally determined diffusion coefficient of RNase (D = 1.21 x 10(-6) cm(2)/s) agrees with literature values for dilute gels and bulk aqueous solutions, thus indicating the gel and the dye had a negligible effect on diffusion. The experimental diffusion coefficient of IGF-I (D = 1.59 x 10(-6) cm(2)/s), in the absence of binding to the fibrin matrix, is consistent with the dimensions of the molecule known from x-ray crystallography and a correlation between D and molecular weight based on 14 other proteins. The experimental method developed here holds promise for determining molecular transport properties of biomolecules under a variety of conditions, for example, when the molecule adsorbs to the gel or is convected through the gel by fluid transport.
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Affiliation(s)
- Jess V Nauman
- Molecular Biosensor and Imaging Center, Institute for Complex Engineered Systems, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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31
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Zhang L, Gardiner BS, Smith DW, Pivonka P, Grodzinsky A. The effect of cyclic deformation and solute binding on solute transport in cartilage. Arch Biochem Biophys 2006; 457:47-56. [PMID: 17107655 DOI: 10.1016/j.abb.2006.10.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Accepted: 10/09/2006] [Indexed: 10/24/2022]
Abstract
Diffusive transport must play an important role in transporting nutrients into cartilage due to its avascular nature. Recent theoretical studies generally support the idea that cyclic loading enhances large molecule transport through advection. However, to date, reactive transport, i.e. the effects of solute binding, has not yet been taken into consideration in cyclically deformed cartilage. In the present study, we develop a reactive transport model to describe the potential role of binding of solute within cyclically deformed cartilage. Our results show that binding does have a significant effect on transport, particularly for the low IGF-I concentrations typical of synovial fluid. A dynamic loading regime of high strain magnitudes (up to 10%) in combination with high frequencies (e.g. 1 Hz) was seen to produce the most dramatic results with enhanced total uptake ratio as high as 25% averaged over the first 5h of cyclic loading.
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Affiliation(s)
- Lihai Zhang
- Department of Civil and Environmental Engineering, The University of Melbourne, Vic, Australia.
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32
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Barta E, Maroudas A. A theoretical study of the distribution of insulin-like growth factor in human articular cartilage. J Theor Biol 2006; 241:628-38. [PMID: 16494900 DOI: 10.1016/j.jtbi.2006.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 12/21/2005] [Accepted: 01/02/2006] [Indexed: 10/25/2022]
Abstract
We present a mathematical simulation which integrates the mechanisms that are currently believed to govern the concentration of the growth factor, IGF1, in cartilage. Articular cartilage is treated as a two-layer continuum: a thin surface layer, exposed to synovial fluid, with a higher cell density, and a deeper layer with impermeable bony endplate. A system of differential equations accounts for diffusion of IGF1 from synovial fluid into, and throughout, the cartilage; IGF1 synthesis, its reactions with soluble binding protein, with cell receptors, and with immobile binding sites on the extracellular matrix. We have collected all available physiologic data relevant to the solution of these equations and used it to compute numerical solutions that yield time dependent profiles for free and complex IGF1 throughout the depth of normal cartilage. Equations for osteoarthritic cartilage were formulated as well. Numerical results indicate a time-scale of several days for IGF1 profiles to settle down after a disturbance. The number of cell receptors for IGF1 appears to be more important than their rate of internalization. There is a lower bound to the number of cell receptors and of immobile binding sites. Parameters that await experimental determination are identified.
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Affiliation(s)
- Efrath Barta
- Department of Biomedical Engineering, Julius Silver Institute of Biomedical Sciences, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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Goodrich LR, Brower-Toland BD, Warnick L, Robbins PD, Evans CH, Nixon AJ. Direct adenovirus-mediated IGF-I gene transduction of synovium induces persisting synovial fluid IGF-I ligand elevations. Gene Ther 2006; 13:1253-62. [PMID: 16708081 DOI: 10.1038/sj.gt.3302757] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Insulin-like growth factor-I (IGF-I) is one of the most influential growth factors in cartilage repair. Maintenance of adequate IGF-I levels after articular repair procedures is complicated by the short biological half-life of IGF-I in vivo. This study investigated the potential for more prolonged IGF-I delivery through direct adenoviral mediated transduction of synovial tissues in the metacarpophalangeal (MCP) joints of horses. The use of a large animal model provided a structurally similar and metabolically relevant corollary to the human knee. The complete IGF-I coding sequence was packaged into an E1-E3 deleted adenovirus-5 vector under cytomegalovirus promoter control (AdIGF-I), and injected at varying total joint doses to the MCP joints of 14 horses. Direct injection of 20 and 50 x 10(10) AdIGF-I resulted in significant elevations of IGF-I in synovial fluid for approximately 21 days. Synovial tissue taken from injected joints at day 35 following injection and compared to tissue taken preinjection from the same joints revealed elevated synoviocyte IGF-I mRNA levels for the highest viral dose by in situ hybridization and real-time PCR techniques. AdIGF-I injections did not result in significant lameness, joint effusion or elevated total protein concentrations in the synovial fluid. Mild mononuclear infiltration of white blood cells was evident in histologic sections of the synovium in the second highest adenoviral IGF-I dose of 20 x 10(10) particles. Cartilage biopsies taken from all injected joints did not reveal any significant changes in proteoglycan levels nor in histological morphology, which included chondrocyte cloning, architecture, cell type or toluidine blue staining, when compared to control joints. Based on these findings, gene transfer of IGF-I to the synovium of joints can result in significant and persistent elevations of IGF-I ligand in synovial fluid with minimal detrimental effects. Direct IGF-I gene therapy may offer a simple approach in treating patients with acute cartilage injury.
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Affiliation(s)
- L R Goodrich
- Comparative Orthopaedics Laboratory, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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Goessler UR, Bugert P, Bieback K, Sadick H, Verse T, Baisch A, Hörmann K, Riedel F. In vitro analysis of matrix proteins and growth factors in dedifferentiating human chondrocytes for tissue-engineered cartilage. Acta Otolaryngol 2005; 125:647-53. [PMID: 16076715 DOI: 10.1080/00016480510029365] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
CONCLUSIONS With ongoing culture and dedifferentiation of chondrocytes, significant changes in the expression patterns of various collagens and the insulin-like growth factor (IGF) receptor were detected. The latter could play an important role in the differentiation of human chondrocytes. OBJECTIVE Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. So far, little is known about the expression of markers for cell proliferation and differentiation in cultured chondrocytes. MATERIAL AND METHODS Human chondrocytes were isolated from septal cartilage (n=5) and held in primary cell culture. Cells were harvested after 24 h and 6 days. Proliferation was analyzed using an Alamar Blue assay. The differentiation of the cells was investigated using bright field microscopy, the expression patterns of various proteins using immunohistochemistry and the expression of distinct genes using a microarray technique. RESULTS The chondrocytes showed strong proliferation (Day 0: 16.7+/-0.7 fluorescent units; Day 5: 52.4+/-2.2 fluorescent units) from the third day of cell culture in medium without growth factors. From this point onwards, a dedifferentiation of the chondrocytes could be observed. In cell culture, the chondrocytes expressed collagen 1 and 10 without expression of collagen 3. After 6 days of cell culture, they expressed collagen 2. The chondrocytes showed constant low expression of the fibroblast growth factor-2 receptor, but constant high expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)2 and MMP9. The cells never expressed the epidermal growth factor receptor. The proportion of IGF receptor-expressing cells diminished significantly during cell culture.
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De Mattei M, Pellati A, Pasello M, Ongaro A, Setti S, Massari L, Gemmati D, Caruso A. Effects of physical stimulation with electromagnetic field and insulin growth factor-I treatment on proteoglycan synthesis of bovine articular cartilage. Osteoarthritis Cartilage 2004; 12:793-800. [PMID: 15450529 DOI: 10.1016/j.joca.2004.06.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Accepted: 06/18/2004] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the single and combined effects of electromagnetic field (EMF) exposure and the insulin growth factor-I (IGF-I) on proteoglycan (PG) synthesis of bovine articular cartilage explants and chondrocytes cultured in monolayers. DESIGN Bovine articular cartilage explants and chondrocyte monolayers were exposed to EMF (75Hz; 1.5mT) for 24h in the absence and in the presence of both 10% fetal bovine serum (FBS) and IGF-I (1-100ng/ml). PG synthesis was determined by Na(2)-(35)SO(4) incorporation. PG release into culture medium was determined by the dimethylmethylene blue (DMMB) assay. RESULTS In cartilage explants, EMF significantly increased (35)S-sulfate incorporation both in the absence and in the presence of 10% FBS. Similarly, IGF-I increased (35)S-sulfate incorporation in a dose-dependent manner both in 0% and 10% FBS. At all doses of IGF-I, the combined effects of the two stimuli resulted additive. No effect was observed on medium PG release. Also in chondrocyte monolayers, IGF-I stimulated (35)S-sulfate incorporation in a dose-dependent manner, both in 0% and 10% FBS, however, this was not modified by EMF exposure. CONCLUSIONS The results of this study show that EMF can act in concert with IGF-I in stimulating PG synthesis in bovine articular cartilage explants. As this effect is not maintained in chondrocyte monolayers, the native cell-matrix interactions in the tissue may be fundamental in driving the EMF effects. These data suggest that in vivo the combination of both EMF and IGF may exert a more chondroprotective effect than either treatment alone on articular cartilage.
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Affiliation(s)
- Monica De Mattei
- Department of Morphology and Embryology, University of Ferrara, 44100 Ferrara, Italy
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De Ceuninck F, Caliez A, Dassencourt L, Anract P, Renard P. Pharmacological disruption of insulin-like growth factor 1 binding to IGF-binding proteins restores anabolic responses in human osteoarthritic chondrocytes. Arthritis Res Ther 2004; 6:R393-403. [PMID: 15380039 PMCID: PMC546277 DOI: 10.1186/ar1201] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Revised: 05/05/2004] [Accepted: 05/19/2004] [Indexed: 12/20/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) has poor anabolic efficacy in cartilage in osteoarthritis (OA), partly because of its sequestration by abnormally high levels of extracellular IGF-binding proteins (IGFBPs). We studied the effect of NBI-31772, a small molecule that inhibits the binding of IGF-1 to IGFBPs, on the restoration of proteoglycan synthesis by human OA chondrocytes. IGFBPs secreted by human OA cartilage or cultured chondrocytes were analyzed by western ligand blot. The ability of NBI-31772 to displace IGF-1 from IGFBPs was measured by radiobinding assay. Anabolic responses in primary cultured chondrocytes were assessed by measuring the synthesis of proteoglycans in cetylpyridinium-chloride-precipitable fractions of cell-associated and secreted 35S-labeled macromolecules. The penetration of NBI-31772 into cartilage was measured by its ability to displace 125I-labeled IGF-1 from cartilage IGFBPs. We found that IGFBP-3 was the major IGFBP secreted by OA cartilage explants and cultured chondrocytes. NBI-31772 inhibited the binding of 125I-labeled IGF-1 to IGFBP-3 at nanomolar concentrations. It antagonized the inhibitory effect of IGFBP-3 on IGF-1-dependent proteoglycan synthesis by rabbit chondrocytes. The addition of NBI-31772 to human OA chondrocytes resulted in the restoration or potentiation of IGF-1-dependent proteoglycan synthesis, depending on the IGF-1 concentrations. However, NBI-31772 did not penetrate into cartilage explants. This study shows that a new pharmacological approach that uses a small molecule inhibiting IGF-1/IGFBP interaction could restore or potentiate proteoglycan synthesis in OA chondrocytes, thereby opening exciting possibilities for the treatment of OA and, potentially, of other joint-related diseases.
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Mauck RL, Hung CT, Ateshian GA. Modeling of neutral solute transport in a dynamically loaded porous permeable gel: implications for articular cartilage biosynthesis and tissue engineering. J Biomech Eng 2004; 125:602-14. [PMID: 14618919 PMCID: PMC2854001 DOI: 10.1115/1.1611512] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A primary mechanism of solute transport in articular cartilage is believed to occur through passive diffusion across the articular surface, but cyclical loading has been shown experimentally to enhance the transport of large solutes. The objective of this study is to examine the effect of dynamic loading within a theoretical context, and to investigate the circumstances under which convective transport induced by dynamic loading might supplement diffusive transport. The theory of incompressible mixtures was used to model the tissue (gel) as a mixture of a gel solid matrix (extracellular matrix/scaffold), and two fluid phases (interstitial fluid solvent and neutral solute), to solve the problem of solute transport through the lateral surface of a cylindrical sample loaded dynamically in unconfined compression with frictionless impermeable platens in a bathing solution containing an excess of solute. The resulting equations are governed by nondimensional parameters, the most significant of which are the ratio of the diffusive velocity of the interstitial fluid in the gel to the solute diffusivity in the gel (Rg), the ratio of actual to ideal solute diffusive velocities inside the gel (Rd), the ratio of loading frequency to the characteristic frequency of the gel (f), and the compressive strain amplitude (epsilon 0). Results show that when Rg > 1, Rd < 1, and f > 1, dynamic loading can significantly enhance solute transport into the gel, and that this effect is enhanced as epsilon 0 increases. Based on representative material properties of cartilage and agarose gels, and diffusivities of various solutes in these gels, it is found that the ranges Rg > 1, Rd < 1, correspond to large solutes, whereas f > 1 is in the range of physiological loading frequencies. These theoretical predictions are thus in agreement with the limited experimental data available in the literature. The results of this study apply to any porous hydrated tissue or material, and it is therefore plausible to hypothesize that dynamic loading may serve to enhance solute transport in a variety of physiological processes.
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Affiliation(s)
| | - Clark T. Hung
- Department of Biomedical Engineering, Columbia University
| | - Gerard A. Ateshian
- Department of Biomedical Engineering, Columbia University
- Department of Mechanical Engineering, Columbia University
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Ham KD, Oegema TR, Loeser RF, Carlson CS. Effects of long-term estrogen replacement therapy on articular cartilage IGFBP-2, IGFBP-3, collagen and proteoglycan levels in ovariectomized cynomolgus monkeys. Osteoarthritis Cartilage 2004; 12:160-8. [PMID: 14723875 DOI: 10.1016/j.joca.2003.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The purpose of this study was to determine the effects of long-term estrogen replacement therapy (ERT) on insulin-like growth factor binding protein (IGFBP)-2, IGFBP-3, collagen and proteoglycan levels in the articular cartilage of the knee joint in a well-characterized monkey model of naturally occurring osteoarthritis (OA). A secondary aim was to evaluate the effect of soy phytoestrogen treatment on these articular cartilage components. DESIGN Monkeys were ovariectomized and given ERT, soy phytoestrogen treatment or no treatment (control) for 3 years. Ten animals were randomly selected from each of the three groups and the cartilage was dissected from the proximal tibia and distal femur of the knee. Levels of IGFBP-2, IGFBP-3, and total protein were measured in cartilage desorptions, and proteoglycan levels and collagen levels were measured in the cartilage tissue. Sections from the tibial plateau of the opposite knee were immunostained using antibodies directed against IGFBPs and evaluated subjectively. RESULTS IGFBP-3 levels were significantly higher, and total protein levels were significantly lower in the cartilage desorption samples from the estrogen-treated animals compared to the control animals. There were no significant differences in IGFBP-2, collagen or proteoglycan levels between the estrogen-treated and control groups. Soy phytoestrogen treatment had no significant effect on the levels of any of the cartilage components that were measured. The staining patterns observed by immunohistochemistry suggested local production of IGFBP-2 and IGFBP-3 by articular cartilage chondrocytes. CONCLUSIONS Long-term estrogen treatment results in increased IGFBP-3 levels in articular cartilage without a significant change in IGFBP-2, collagen or proteoglycan content, and IGFBP-3 appears to be synthesized by articular cartilage chondrocytes. Long-term soy phytoestrogen treatment did not have a statistically significant effect on the levels of IGFBP-2, IGFBP-3, collagen or proteoglycan.
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Affiliation(s)
- K D Ham
- College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA.
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Garcia AM, Szasz N, Trippel SB, Morales TI, Grodzinsky AJ, Frank EH. Transport and binding of insulin-like growth factor I through articular cartilage. Arch Biochem Biophys 2003; 415:69-79. [PMID: 12801514 DOI: 10.1016/s0003-9861(03)00215-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study focused on the role of insulin-like growth factor (IGF) binding proteins (IGFBPs) in cartilage on the transport and binding of IGF-I within the tissue. We have developed experimental and theoretical modeling techniques to quantify and contrast the roles of diffusion, binding, fluid convection, and electrical migration on the transport of IGF-I within cartilage tissue. Bovine articular cartilage disks were equilibrated in buffer containing 125I-IGF-I and graded levels of unlabeled IGF-I. Equilibrium binding, as measured by the uptake ratio of 125I-IGF-I in the tissue (free plus bound) to the concentration of labeled species in the buffer, was found to be consistent with a first-order reversible binding model involving one dominant family of binding sites within the matrix. Western ligand blots revealed a major IGF binding doublet around 23 kDa, which has been previously shown to coincide with IGFBP-6. Diffusive transport of 125I-IGF-I through cartilage was measured and found to be consistent with a diffusion-limited reaction theoretical model incorporating first-order reversible binding. Addition of excess amounts of unlabeled IGF-I during steady state transport of 125I-IGF-I resulted in release of bound 125I-IGF-I from the tissue, as predicted by the diffusion-reaction model. In contrast, addition of the low-affinity Des(1-3)IGF-I analog did not result in release of bound 125I-IGF-I. Application of electric current was used to augment transport of IGF-I through cartilage via electroosmosis and electrophoresis. Taken together, our results suggest that a single dominant substrate family, the high-affinity IGFBPs, is responsible for much of the observed binding of IGF-I within cartilage. The data suggest that intratissue fluid flow, such as that induced by mechanical loading of cartilage in vivo may be expected to enhance IGF transport by an order of magnitude and that this increment may help to counterbalance the restrictions encountered by the immobilization of IGFs by the binding proteins.
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Affiliation(s)
- A Minerva Garcia
- Continuum Electromechanics Group, Center for Biomedical Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Jin M, Emkey GR, Siparsky P, Trippel SB, Grodzinsky AJ. Combined effects of dynamic tissue shear deformation and insulin-like growth factor I on chondrocyte biosynthesis in cartilage explants. Arch Biochem Biophys 2003; 414:223-31. [PMID: 12781774 DOI: 10.1016/s0003-9861(03)00195-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biophysical forces and biochemical factors play crucial roles in the maintenance of the integrity of articular cartilage. In this study, we explored the effect of dynamic tissue shear deformation and insulin-like growth factor I (IGF-I) on matrix synthesis by chondrocytes within native cartilage explants. Dynamic tissue shear in the range of 0.5-6% strain amplitude at 0.1 Hz was applied to cartilage explants cultured in serum-free medium. Dynamic tissue shear above 1.5% strain amplitude significantly stimulated protein and proteoglycan synthesis, by maximum values of 35 and 25%, respectively, over statically held control specimens. In the absence of tissue shear, IGF-I augmented protein and proteoglycan synthesis up to twofold at IGF-I concentrations in the range of 100-300 ng/ml. When tissue shear and IGF-I stimuli were combined, matrix biosynthesis levels were significantly higher than the maximal effect caused by either stimulus alone. However, there was no significant interaction between tissue shear and IGF-I as determined by two-way ANOVA. We then quantified the effect of dynamic tissue shear on the transport of IGF-I into and within cartilage explants. [125I]IGF-I was added to the medium, and the levels of intratissue [125I]IGF-I were directly measured as a function of time over 48 h in the presence and absence of continuous dynamic shear strain. Dynamic shear did not alter the rate of uptake of [125I]IGF-I into the explants, suggesting that convective diffusion of [125I]IGF-I is negligible under the shear strain conditions used. This is in marked contrast to the enhancement of transport reported in response to uniaxial dynamic compression. Taken together, these data suggest that (1) the stimulatory effect of tissue shear is via mechanotransduction pathways and not by facilitated transport of biochemical factors and (2) chondrocytes may possess complementary signal transduction pathways for biophysical and biochemical factors leading to changes in metabolic activity.
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Affiliation(s)
- Moonsoo Jin
- Continuum Electromechanics Group, Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Purple CR, Untermann TG, Pichika R, Homandberg GA. Fibronectin fragments upregulate insulin-like growth factor binding proteins in chondrocytes. Osteoarthritis Cartilage 2002; 10:734-46. [PMID: 12202126 DOI: 10.1053/joca.2002.0808] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
UNLABELLED Addition of fibronectin fragments (Fn-fs) to cultured cartilage explants has been shown to mediate extensive cartilage matrix degradation followed by anabolic responses. OBJECTIVE To determine whether specific Fn-fs regulate cartilage metabolism through a mechanism, in part, involving insulin-like growth factor (IGF) and insulin-like growth factor binding proteins (IGFBPs). METHODS Primary bovine articular chondrocyte cultures were treated with Fn-fs. mRNA from the cultures was analysed by Northern blotting. Changes in the levels of IGFBPs in cellular extracts and conditioned media were analysed by Western ligand blotting. Explant cultures of bovine articular cartilage were used to assay release of exogenous IGF-I and IGFBP-2. An analog of IGF-I with altered affinity for IGFBPs was used to assay the effect of IGFBPs on proteoglycan synthesis. RESULTS The Fn-fs increased protein levels of IGFBPs-2, -3 and -5 in conditioned media and of IGFBP-2 in cell extracts by as much as nine-fold. Conversely, the protein level of constitutively expressed IGBP-4 was decreased in conditioned medium. Northern blot analysis reflected increased IGFBP-3 mRNA but not decreased IGFBP-4 mRNA. The IGF-I analog was more effective at restoring PG synthesis suppression by Fn-fs than was wild type IGF-I. CONCLUSIONS The Fn-fs increased levels of IGFBPs in cultures of bovine articular chondrocytes and elicited release of IGFBP-2 and IGF-I from articular cartilage. The increased level of IGFBPs may trap IGF-I and account in part for the initial suppression of PG synthesis. Induced proteinases may subsequently liberate IGF-I and cause greatly enhanced anabolic processes, contributing to cartilage repair.
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Affiliation(s)
- C R Purple
- Department of Biochemistry, Rush Medical College at Rush-Presbyterian-St. Luke's Medical Center, 1653 West Congress Parkway, Chicago, IL 60612-3864, USA
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van der Kraan PM, Buma P, van Kuppevelt T, van den Berg WB. Interaction of chondrocytes, extracellular matrix and growth factors: relevance for articular cartilage tissue engineering. Osteoarthritis Cartilage 2002; 10:631-7. [PMID: 12479385 DOI: 10.1053/joca.2002.0806] [Citation(s) in RCA: 180] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
UNLABELLED The abundant extracellular matrix of articular cartilage has to be maintained by a limited number of chondrocytes. Vice versa, the extracellular matrix has an important role in the regulation of chondrocyte function. OBJECTIVE In this review we discuss the role of the extracellular matrix in the regulation of chondrocyte function and the relevance for cartilage tissue engineering. To reach this goal the international literature on this subject has been searched with a major focus on the last 5 years. RESULTS Structural matrix macromolecules (e.g. collagen, hyaluronate), but also growth factors (e.g. IGF-I, TGF beta) entrapped in the matrix and released under specific conditions affect chondrocyte behavior. These factors communicate with the chondrocyte via specific membrane receptors. In this way there is a close interaction between the extracellular and intracellular milieu. Articular cartilage has a limited capacity of intrinsic repair, which has resulted in the development of tissue engineering approaches to repair damaged cartilage. Successful application of scaffolds has to take into account the important role of both soluble and insoluble matrix-derived factors in cartilage homeostasis. CONCLUSION Functional tissue engineering will only be realized when the scaffolds used will provide cartilage cells with the correct extracellular signals.
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Affiliation(s)
- P M van der Kraan
- Laboratory for Experimental Rheumatology and Advanced Therapeutics, Nijmegen Center for Molecular Life Sciences, University Medical Center Nijmegen, Geert Grooteplein 26-28 Nijmegen, The Netherlands.
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Hoeflich A, Reisinger R, Vargas GA, Elmlinger MW, Schuett B, Jehle PM, Renner-Müller I, Lahm H, Russo VC, Wolf E. Mutation of the RGD sequence does not affect plasma membrane association and growth inhibitory effects of elevated IGFBP-2 in vivo. FEBS Lett 2002; 523:63-7. [PMID: 12123805 DOI: 10.1016/s0014-5793(02)02935-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Using insulin-like growth factor-binding protein-2 (IGFBP-2) transgenic mice (D mice) as a model of elevated IGFBP-2 expression, which is often found in unphysiological conditions, we found association of IGFBP-2 to purified plasma membranes of many organs. To determine whether the RGD (Arg-Gly-Asp) motif of IGFBP-2 mediates cell surface binding in vivo, we mutated the RGD motif of IGFBP-2 into an RGE (Arg-Gly-Glu) sequence and produced transgenic mice (E mice) which express elevated amounts of mutated IGFBP-2. Our data demonstrate that in vivo IGFBP-2 cell surface association is not dependent on the RGD motif and that mutation of this sequence does not alter growth inhibitory effects of IGFBP-2.
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Affiliation(s)
- A Hoeflich
- Institute of Molecular Animal Breeding, Gene Center, Ludwig-Maximilian University, Feodor-Lynen-Str. 25, 81377, Munich, Germany.
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Clemmons DR, Busby WH, Garmong A, Schultz DR, Howell DS, Altman RD, Karr R. Inhibition of insulin-like growth factor binding protein 5 proteolysis in articular cartilage and joint fluid results in enhanced concentrations of insulin-like growth factor 1 and is associated with improved osteoarthritis. ARTHRITIS AND RHEUMATISM 2002; 46:694-703. [PMID: 11920405 DOI: 10.1002/art.10222] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The complement component C1s is present in dog joint fluid in an activated state. Since C1s degrades insulin-like growth factor binding protein 5 (IGFBP-5), we undertook to determine whether inhibiting C1s in joint fluid would result in an increase in the amount of intact IGFBP-5 and IGF-1 in cartilage and joint fluid, and whether C1s inhibition would be associated with a reduction in cartilage destruction during the development of osteoarthritis (OA). METHODS Twenty-two dogs were randomized to 3 treatment groups. All dogs underwent anterior cruciate ligament transection and were exercised. Dogs received 1 of 3 treatments: buffer alone (controls; n = 6); PB-145, a peptide derived from the sequence of antithrombin III (n = 9); and pentosan polysulfate (PPS; n = 7). PB-145 or saline was injected into the joint space 3 times per week for 3 weeks. PPS was injected intramuscularly weekly for 3 weeks. RESULTS Joint histology showed preservation of chondrocytes and a smooth joint surface in the animals treated with PB-145 and PPS. Mankin scoring showed statistically significant reductions in joint destruction with PB-145 and PPS treatments (P < 0.01) compared with buffer control. Mean active collagenase concentrations were decreased by these two treatments. Immunoblotting of joint fluid showed that both treatments increased concentrations of intact IGFBP-5. Direct analysis of IGFBP-3 and IGFBP-5 protease activity showed that IGFBP-5 was degraded more rapidly and that PB-145 and PPS inhibited the degradation of both proteins. Total IGF-1 concentrations in joint fluid were increased 5.6-5.8-fold by these two treatments. Analysis showed that C1s was being activated in joint fluid and that its activation was inhibited by the addition of PB-145 or PPS. CONCLUSION The findings suggest that direct inhibition of the serine protease C1s results in increased concentrations of intact IGFBP-5 and that proteolysis of IGFBP-3 is also inhibited, probably by the inhibition of some other protease. This increase in concentrations of intact IGFBP-3 and IGFBP-5 leads to an increase in IGF-1 which is associated with an improvement in joint architecture during the development of OA.
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Affiliation(s)
- David R Clemmons
- Division of Endocrinology, University of North Carolina, Chapel Hill, 27599-7170, USA.
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Grodzinsky AJ, Levenston ME, Jin M, Frank EH. Cartilage tissue remodeling in response to mechanical forces. Annu Rev Biomed Eng 2002; 2:691-713. [PMID: 11701528 DOI: 10.1146/annurev.bioeng.2.1.691] [Citation(s) in RCA: 471] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies suggest that there are multiple regulatory pathways by which chondrocytes in articular cartilage sense and respond to mechanical stimuli, including upstream signaling pathways and mechanisms that may lead to direct changes at the level of transcription, translation, post-translational modifications, and cell-mediated extracellular assembly and degradation of the tissue matrix. This review focuses on the effects of mechanical loading on cartilage and the resulting chondrocyte-mediated biosynthesis, remodeling, degradation, and repair of this tissue. The effects of compression and tissue shear deformation are compared, and approaches to the study of mechanical regulation of gene expression are described. Of particular interest regarding dense connective tissues, recent experiments have shown that mechanotransduction is critically important in vivo in the cell-mediated feedback between physical stimuli, the molecular structure of newly synthesized matrix molecules, and the resulting macroscopic biomechanical properties of the tissue.
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Affiliation(s)
- A J Grodzinsky
- Department of Electrical Engineering and Computer Science, Department of Mechanical Engineering, Division of Bioengineering and Environmental Health, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Dubaquié Y, Mortensen DL, Intintoli A, Hogue DA, Nakamura G, Rancatore P, Lester P, Sadick MD, Filvaroff E, Fielder PJ, Lowman HB. Binding protein-3-selective insulin-like growth factor I variants: engineering, biodistributions, and clearance. Endocrinology 2001; 142:165-73. [PMID: 11145579 DOI: 10.1210/endo.142.1.7864] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor I (IGF-I) is a potent anabolic peptide that mediates most of its pleiotropic effects through association with the IGF type I receptor. Biological availability and plasma half-life of IGF-I are modulated by soluble binding proteins (IGFBPs), which sequester free IGF-I into high affinity complexes. Elevated levels of specific IGFBPs have been observed in several pathological conditions, resulting in inhibition of IGF-I activity. Administration of IGF-I variants that are unable to bind to the up-regulated IGFBP species could potentially counteract this effect. We engineered two IGFBP-selective variants that demonstrated 700- and 80,000-fold apparent reductions in affinity for IGFBP-1 while preserving low nanomolar affinity for IGFBP-3, the major carrier of IGF-I in plasma. Both variants displayed wild-type-like potency in cellular receptor kinase assays, stimulated human cartilage matrix synthesis, and retained their ability to associate with the acid-labile subunit in complex with IGFBP-3. Furthermore, pharmacokinetic parameters and tissue distribution of the IGF-I variants in rats differed from those of wild-type IGF-I as a function of their IGFBP affinities. These IGF-I variants may potentially be useful for treating disease conditions associated with up-regulated IGFBP-1 levels, such as chronic or acute renal and hepatic failure or uncontrolled diabetes. More generally, these results suggest that the complex biology of IGF-I may be clarified through in vivo studies of IGFBP-selective variants.
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Affiliation(s)
- Y Dubaquié
- Departments of Protein Engineering Genentech, Inc., South San Francisco, California 94080, USA
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