251
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Kumagai K, Sakai K, Kusayama Y, Akamatsu Y, Sakamaki K, Morita S, Sasaki T, Saito T, Sakai T. The extent of degeneration of cruciate ligament is associated with chondrogenic differentiation in patients with osteoarthritis of the knee. Osteoarthritis Cartilage 2012; 20:1258-67. [PMID: 22846713 DOI: 10.1016/j.joca.2012.07.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 07/12/2012] [Accepted: 07/18/2012] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Degeneration in cruciate ligaments results from abnormal biomechanical stress and the aging process. Such degeneration is a common outcome in patients with osteoarthritis (OA) of the knee and contributes to the progression of OA. However, to date, there are no specific markers that can predict the extent of ligament degeneration. We hypothesized that the extent of degeneration has correlations to increased chondrogenic potential. METHODS Twenty anterior cruciate ligaments (ACLs) and 30 posterior cruciate ligaments (PCLs) from 30 knees of 28 adult patients with OA at the time of total knee arthroplasty were used for the study. Degeneration was histologically assessed using a grading system. Expressions of Scleraxis (as a ligament cell marker) and Sry-type HMG box 9 (SOX9) (as a chondrogenic marker) were immunohistochemically assessed in each grade. RESULTS We found the opposite expression pattern between Scleraxis and SOX9 according to the grade. The percentage of Scleraxis-positive cells decreased significantly by grade (60.9±23.7 in grade 1, 39.7±30.5 in grade 2, and 13.9±27.1 in grade 3, P<0.0001). In contrast, the percentage of SOX9-positive cells increased significantly by grade (2.5±4.9 in grade 1, 17.5±13.4 in grade 2, and 50.9±27.1 in grade 3, P<0.0001). Furthermore, co-localized expression of both Scleraxis and SOX9 was demonstrated in chondrocyte-like cells. CONCLUSIONS This study indicates that chondrogenic differentiation is associated with the progression of degeneration in human ligaments. Our results suggest that the expression of SOX9 as a chondrogenic marker could be an indicator for the extent of degeneration in human ligaments. It remains to be elucidated whether suppression of chondrogenic differentiation can prevent progression of the degenerative process of cruciate ligaments in patients with OA.
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Affiliation(s)
- K Kumagai
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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252
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Evans RB. Managing the injured tendon: current concepts. J Hand Ther 2012; 25:173-89; quiz 190. [PMID: 22326362 DOI: 10.1016/j.jht.2011.10.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 10/31/2011] [Indexed: 02/03/2023]
Abstract
Despite advances in understanding of the mechanical aspects of tendon management with improved suture technique and early stress application with postoperative therapy, clinical results remain inconsistent after repair, especially within the synovial regions. Complementary research to enhance the intrinsic pathway of healing, suppress the extrinsic pathway of healing, and manipulate frictional resistance to tendon gliding is now the focus of current basic science research on tendons. In the future, application of these new biologic therapies may increase the "safety zone" (or tolerance for load and excursion without dysfunctional gapping) as therapists apply stress to healing tendons and may alter future rehabilitation protocols by allowing greater angles of motion (and thus tendon excursion), increased external load, and decreased time in protective orthoses (splints). However, at this time, the stronger repair techniques and the application of controlled stress remain the best and most well-supported intervention after tendon injury and repair in the recovery of functional tendon excursion and joint range of motion. The hand therapist's role in this process remains a critical component contributing to satisfactory outcomes.
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Affiliation(s)
- Roslyn B Evans
- Indian River Hand and Upper Extremity Rehabilitation, Vero Beach, Florida 32960, USA.
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253
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Moriya K, Sakai K, Yan MH, Sakai T. Fibronectin is essential for survival but is dispensable for proliferation of hepatocytes in acute liver injury in mice. Hepatology 2012; 56:311-21. [PMID: 22318920 PMCID: PMC3355232 DOI: 10.1002/hep.25624] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 01/18/2012] [Indexed: 01/19/2023]
Abstract
UNLABELLED Acute liver injury causes massive hepatocyte apoptosis and/or fatal liver damage. Fibronectin, an extracellular matrix glycoprotein, is prominently expressed during adult tissue repair. However, the extent of fibronectin dependence on hepatocyte response to acute liver damage remains to be defined. Because identification of hepatic survival factors is critical for successful therapeutic intervention in liver failure, this relationship has been investigated using a fibronectin-deficient mouse model of acute liver injury. Here, we show that lack of fibronectin induces significantly increased hepatocyte apoptosis, which is accompanied by significant down-regulation of the antiapoptotic protein, B-cell lymphoma-extra large (Bcl-xL). Furthermore, fibronectin deficiency leads to a significantly elevated production of hepatocyte growth factor in hepatic stellate cells postinjury, which, in turn, results in an earlier onset and acceleration of hepatocyte regeneration. Primary hepatocytes on fibronectin are protected from reactive oxygen species-induced cellular damage, retaining the expression of Bcl-xL, whereas those on type I collagen are not. This retained expression of Bcl-xL is inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. CONCLUSION We provide evidence that fibronectin-mediated matrix survival signals for hepatocytes are transduced through the PI3K/Bcl-xL-signaling axis in response to injury. This work defines fibronectin as a novel antiapoptotic factor for hepatocytes after acute liver injury, but demonstrates that fibronectin is not essential for subsequent hepatocyte proliferation.
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Affiliation(s)
- Kei Moriya
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
| | - Keiko Sakai
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
| | - Michel H. Yan
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
| | - Takao Sakai
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA,Orthopaedic and Rheumatologic Research Center, Cleveland Clinic, Cleveland, Ohio 44195, USA,Department of Anatomical Pathology, Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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254
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Abstract
Intimal hyperplasia is the leading cause of long-term failure in coronary artery bypass vein grafting, coronary artery stenting, angioplasty, arteriovenous fistula for dialysis, and allograft transplantation. Intimal hyperplasia is a product of vascular smooth muscle cell proliferation, migration through the internal elastic lamina, and deposition of extracellular matrix proteins driven by growth factors in the vasculature. This vascular pathology results in a progressive diminution of the vessel lumen and serves as a site for thrombosis and atherosclerotic lesions. A key cell type in the initiation of intimal hyperplasia is the vascular endothelial cell, which appears to have down-stream effects on the vascular smooth muscle proliferation and migration. Currently, the only means available for prevention of intimal hyperplasia is through inhibition of mammalian target of rapamycin (mTOR) with the immunosuppressant rapamycin. mTOR integrates up-stream signals from growth factors such as IL-2 and senses the cellular nutrient and energy levels and redox status. This presentation will discuss the potential means of preserving the vascular endothelial cell and, thereby, reducing the development of intimal hyperplasia in our open-heart surgical patients.
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Affiliation(s)
- B Mills
- Circulatory Sciences Graduate Perfusion Program, The University of Arizona, Tucson, AZ, USA
| | - T Robb
- Circulatory Sciences Graduate Perfusion Program, The University of Arizona, Tucson, AZ, USA
| | - DF Larson
- Circulatory Sciences Graduate Perfusion Program, The University of Arizona, Tucson, AZ, USA
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255
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Abstract
The local microenvironment, or niche, of a cancer cell plays important roles in cancer development. A major component of the niche is the extracellular matrix (ECM), a complex network of macromolecules with distinctive physical, biochemical, and biomechanical properties. Although tightly controlled during embryonic development and organ homeostasis, the ECM is commonly deregulated and becomes disorganized in diseases such as cancer. Abnormal ECM affects cancer progression by directly promoting cellular transformation and metastasis. Importantly, however, ECM anomalies also deregulate behavior of stromal cells, facilitate tumor-associated angiogenesis and inflammation, and thus lead to generation of a tumorigenic microenvironment. Understanding how ECM composition and topography are maintained and how their deregulation influences cancer progression may help develop new therapeutic interventions by targeting the tumor niche.
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Affiliation(s)
- Pengfei Lu
- Breakthrough Breast Cancer Research Unit, University of Manchester, Manchester M20 4BX, England, UK
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256
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Otranto M, Sarrazy V, Bonté F, Hinz B, Gabbiani G, Desmoulière A. The role of the myofibroblast in tumor stroma remodeling. Cell Adh Migr 2012; 6:203-19. [PMID: 22568985 PMCID: PMC3427235 DOI: 10.4161/cam.20377] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Since its first description in wound granulation tissue, the myofibroblast has been recognized to be a key actor in the epithelial-mesenchymal cross-talk that plays a crucial role in many physiological and pathological situations, such as regulation of prostate development, ventilation-perfusion in lung alveoli or organ fibrosis. The presence of myofibroblasts in the stroma reaction to epithelial tumors is well established and many data are accumulating which suggest that the stroma compartment is an active participant in tumor onset and/or evolution. In this review we summarize the evidence in favor of this concept, the main mechanisms that regulate myofibroblast differentiation and function, as well as the biophysical and biochemical factors possibly involved in epithelial-stroma interactions, using liver carcinoma as main model, in view of achieving a better understanding of tumor progression mechanisms and of tools directed toward stroma as eventual therapeutic target.
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Affiliation(s)
- Marcela Otranto
- Department of Physiology, Faculty of Pharmacy, University of Limoges, Limoges, France
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257
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Mendias CL, Gumucio JP, Lynch EB. Mechanical loading and TGF-β change the expression of multiple miRNAs in tendon fibroblasts. J Appl Physiol (1985) 2012; 113:56-62. [PMID: 22539168 DOI: 10.1152/japplphysiol.00301.2012] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tendons link skeletal muscles to bones and are important components of the musculoskeletal system. There has been much interest in the role of microRNA (miRNA) in the regulation of musculoskeletal tissues to mechanical loading, inactivity, and disease, but it was unknown whether miRNA is involved in the adaptation of tendons to mechanical loading. We hypothesized that mechanical loading and transforming growth factor-β (TGF-β) treatment would regulate the expression of several miRNA molecules with known roles in cell proliferation and extracellular matrix synthesis. To test our hypothesis, we subjected untrained adult rats to a single session of mechanical loading and measured the expression of several miRNA transcripts in Achilles tendons. Additionally, as TGF-β is known to be an important regulator of tendon growth and adaptation, we treated primary tendon fibroblasts with TGF-β and measured miRNA expression. Both mechanical loading and TGF-β treatment modulated the expression of several miRNAs that regulate cell proliferation and extracellular matrix synthesis. We also identified mechanosensitive miRNAs that may bind to the 3'-untranslated region of the basic helix-loop-helix transcription factor scleraxis, which is a master regulator of limb tendon development. The results from this study provide novel insight into the mechanobiology of tendons and indicate that miRNA could play an important role in the adaptation of tendons to growth stimuli.
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Affiliation(s)
- Christopher L Mendias
- Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-2200, USA.
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258
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Mendias CL, Gumucio JP, Bakhurin KI, Lynch EB, Brooks SV. Physiological loading of tendons induces scleraxis expression in epitenon fibroblasts. J Orthop Res 2012; 30:606-12. [PMID: 21913219 PMCID: PMC3245815 DOI: 10.1002/jor.21550] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 08/22/2011] [Indexed: 02/04/2023]
Abstract
Scleraxis is a basic helix-loop-helix transcription factor that plays a central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons. Mice with a targeted inactivation of scleraxis (Scx(-/-)) fail to properly form limb tendons, but the role that scleraxis has in regulating the growth and adaptation of tendons of adult organisms is unknown. To determine if scleraxis expression changes in response to a physiological growth stimulus to tendons, we subjected adult mice that express green fluorescent protein (GFP) under the control of the scleraxis promoter (ScxGFP) to a 6-week-treadmill training program designed to induce adaptive growth in Achilles tendons. Age matched sedentary ScxGFP mice were used as controls. Scleraxis expression was sparsely observed in the epitenon region of sedentary mice, but in response to treadmill training, scleraxis was robustly expressed in fibroblasts that appeared to be emerging from the epitenon and migrating into the superficial regions of tendon fascicles. Treadmill training also led to an increase in scleraxis, tenomodulin, and type I collagen gene expression as measured by qPCR. These results suggest that in addition to regulating the embryonic formation of limb tendons, scleraxis also appears to play an important role in the adaptation of adult tendons to physiological loading.
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Affiliation(s)
- Christopher L Mendias
- Orthopaedic Surgery, University of Michigan, Ann Arbor, 48109,Kinesiology, University of Michigan, Ann Arbor, 48109,Corresponding author Christopher Mendias, PhD, ATC, University of Michigan, 109 Zina Pitcher Place, BSRB 2017, Ann Arbor, MI 48109-2200, 734-764-3250 office, 734-647-0003 fax
| | - Jonathan P Gumucio
- Orthopaedic Surgery, University of Michigan, Ann Arbor, 48109,Kinesiology, University of Michigan, Ann Arbor, 48109
| | | | - Evan B Lynch
- Orthopaedic Surgery, University of Michigan, Ann Arbor, 48109
| | - Susan V Brooks
- Molecular & Integrative Physiology, University of Michigan, Ann Arbor, 48109,Biomedical Engineering, University of Michigan, Ann Arbor, 48109
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259
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Sun Y, Chen CS, Fu J. Forcing stem cells to behave: a biophysical perspective of the cellular microenvironment. Annu Rev Biophys 2012; 41:519-42. [PMID: 22404680 DOI: 10.1146/annurev-biophys-042910-155306] [Citation(s) in RCA: 297] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Physical factors in the local cellular microenvironment, including cell shape and geometry, matrix mechanics, external mechanical forces, and nanotopographical features of the extracellular matrix, can all have strong influences on regulating stem cell fate. Stem cells sense and respond to these insoluble biophysical signals through integrin-mediated adhesions and the force balance between intracellular cytoskeletal contractility and the resistant forces originated from the extracellular matrix. Importantly, these mechanotransduction processes can couple with many other potent growth-factor-mediated signaling pathways to regulate stem cell fate. Different bioengineering tools and microscale/nanoscale devices have been successfully developed to engineer the physical aspects of the cellular microenvironment for stem cells, and these tools and devices have proven extremely powerful for identifying the extrinsic physical factors and their downstream intracellular signaling pathways that control stem cell functions.
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Affiliation(s)
- Yubing Sun
- Integrated Biosystems and Biomechanics Laboratory, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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260
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Hayashi H, Sakai T. Biological Significance of Local TGF-β Activation in Liver Diseases. Front Physiol 2012; 3:12. [PMID: 22363291 PMCID: PMC3277268 DOI: 10.3389/fphys.2012.00012] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 01/17/2012] [Indexed: 12/20/2022] Open
Abstract
The cytokine transforming growth factor-β (TGF-β) plays a pivotal role in a diverse range of cellular responses, including cell proliferation, apoptosis, differentiation, migration, adhesion, angiogenesis, stimulation of extracellular matrix (ECM) synthesis, and downregulation of ECM degradation. TGF-β and its receptors are ubiquitously expressed by most cell types and tissues in vivo. In intact adult tissues and organs, TGF-β is secreted in a biologically inactive (latent) form associated in a non-covalent complex with the ECM. In response to injury, local latent TGF-β complexes are converted into active TGF-β according to a tissue- and injury type-specific activation mechanism. Such a well and tightly orchestrated regulation in TGF-β activity enables an immediate, highly localized response to type-specific tissue injury. In the pathological process of liver fibrosis, TGF-β plays as a master profibrogenic cytokine in promoting activation and myofibroblastic differentiation of hepatic stellate cells, a central event in liver fibrogenesis. Continuous and/or persistent TGF-β signaling induces sustained production of ECM components and of tissue inhibitor of metalloproteinase synthesis. Therefore, the regulation of locally activated TGF-β levels is increasingly recognized as a therapeutic target for liver fibrogenesis. This review summarizes our present knowledge of the activation mechanisms and bioavailability of latent TGF-β in biological and pathological processes in the liver.
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Affiliation(s)
- Hiromitsu Hayashi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic Cleveland, OH, USA
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261
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Abstract
Mechanotransduction, the conversion of a biophysical force into a cellular response, allows cells and tissues to respond to their mechanical milieu. How muscle force is translated through TGF-β signaling to regulate tendon homeostasis offers an interesting in vivo example of mechanotransduction.
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Affiliation(s)
- Amnon Sharir
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
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262
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Abstract
Extracellular signaling molecules have crucial roles in development and homeostasis, and their incorrect deployment can lead to developmental defects and disease states. Signaling molecules are released from sending cells, travel to target cells, and act over length scales of several orders of magnitude, from morphogen-mediated patterning of small developmental fields to hormonal signaling throughout the organism. We discuss how signals are modified and assembled for transport, which routes they take to reach their targets, and how their range is affected by mobility and stability.
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Affiliation(s)
- Patrick Müller
- Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Broad Institute, Center for Brain Science, FAS Center for Systems Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
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263
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Abstract
INTRODUCTION Tendons establish specific connections between muscles and the skeleton by transferring contraction forces from skeletal muscle to bone thereby allowing body movement. Tendon physiology and pathology are heavily dependent on mechanical stimuli. Tendon injuries clinically represent a serious and still unresolved problem since damaged tendon tissues heal very slowly and no surgical treatment can restore a damaged tendon to its normal structural integrity and mechanical strength. Understanding how mechanical stimuli regulate tendon tissue homeostasis and regeneration will improve the treatment of adult tendon injuries that still pose a great challenge in today's medicine. SOURCE OF DATA This review summarizes the current status of tendon treatment and discusses new directions from the point of view of cell-based therapy and regenerative medicine approach. We searched the available literature using PubMed for relevant original articles and reviews. GROWING POINTS Identification of tendon cell markers has enabled us to study precisely tendon healing and homeostasis. Clinically, tissue engineering for tendon injuries is an emerging technology comprising elements from the fields of cellular source, scaffold materials, growth factors/cytokines and gene delivering systems. AREAS TIMELY FOR DEVELOPING RESEARCH The clinical settings to establish appropriate microenvironment for injured tendons with the combination of these novel cellular- and molecular-based scaffolds will be critical for the treatment.
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Affiliation(s)
- Tomoya Sakabe
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, ND20, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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