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Parker JB, Valencia C, Akras D, DiIorio SE, Griffin MF, Longaker MT, Wan DC. Understanding Fibroblast Heterogeneity in Form and Function. Biomedicines 2023; 11:2264. [PMID: 37626760 PMCID: PMC10452440 DOI: 10.3390/biomedicines11082264] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/09/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Historically believed to be a homogeneous cell type that is often overlooked, fibroblasts are more and more understood to be heterogeneous in nature. Though the mechanisms behind how fibroblasts participate in homeostasis and pathology are just beginning to be understood, these cells are believed to be highly dynamic and play key roles in fibrosis and remodeling. Focusing primarily on fibroblasts within the skin and during wound healing, we describe the field's current understanding of fibroblast heterogeneity in form and function. From differences due to embryonic origins to anatomical variations, we explore the diverse contributions that fibroblasts have in fibrosis and plasticity. Following this, we describe molecular techniques used in the field to provide deeper insights into subpopulations of fibroblasts and their varied roles in complex processes such as wound healing. Limitations to current work are also discussed, with a focus on future directions that investigators are recommended to take in order to gain a deeper understanding of fibroblast biology and to develop potential targets for translational applications in a clinical setting.
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Affiliation(s)
- Jennifer B. Parker
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Caleb Valencia
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
| | - Deena Akras
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
| | - Sarah E. DiIorio
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michelle F. Griffin
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
| | - Michael T. Longaker
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
| | - Derrick C. Wan
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA (M.F.G.)
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Ligament Alteration in Diabetes Mellitus. J Clin Med 2022; 11:jcm11195719. [PMID: 36233586 PMCID: PMC9572847 DOI: 10.3390/jcm11195719] [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: 07/24/2022] [Revised: 09/21/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Connective tissue ageing is accelerated by the progressive accumulation of advanced glycation end products (AGEs). The formation of AGEs is characteristic for diabetes mellitus (DM) progression and affects only specific proteins with relatively long half-lives. This is the case of fibrillar collagens that are highly susceptible to glycation. While collagen provides a framework for plenty of organs, the local homeostasis of specific tissues is indirectly affected by glycation. Among the many age- and diabetes-related morphological changes affecting human connective tissues, there is concurrently reduced healing capacity, flexibility, and quality among ligaments, tendons, bones, and skin. Although DM provokes a wide range of known clinical disorders, the exact mechanisms of connective tissue alteration are still being investigated. Most of them rely on animal models in order to conclude the patterns of damage. Further research and more well-designed large-cohort studies need to be conducted in order to answer the issue concerning the involvement of ligaments in diabetes-related complications. In the following manuscript, we present the results from experiments discovering specific molecules that are engaged in the degenerative process of connective tissue alteration. This review is intended to provide the report and sum up the investigations described in the literature concerning the topic of ligament alteration in DM, which, even though significantly decreasing the quality of life, do not play a major role in research.
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Abstract
Tendons are collagen-rich musculoskeletal tissues that possess the mechanical strength needed to transfer forces between muscles and bones. The mechanical development and function of tendons are impacted by collagen crosslinks. However, there is a limited understanding of how collagen crosslinking is regulated in tendon during development and aging. Therefore, the objective of the present review was to highlight potential regulators of enzymatic and non-enzymatic collagen crosslinking and how they impact tendon function. The main collagen crosslinking enzymes include lysyl oxidase (LOX) and the lysyl oxidase-like isoforms (LOXL), whereas non-enzymatic crosslinking is mainly mediated by the formation of advanced glycation end products (AGEs). Regulators of the LOX and LOXL enzymes may include mechanical stimuli, mechanotransducive cell signaling pathways, sex hormones, transforming growth factor (TGF)β family, hypoxia, and interactions with intracellular or extracellular proteins. AGE accumulation in tendon is due to diabetic conditions and aging, and can be mediated by diet and mechanical stimuli. The formation of these enzymatic and non-enzymatic collagen crosslinks plays a major role in tendon biomechanics and in the mechanisms of force transfer. A more complete understanding of how enzymatic and non-enzymatic collagen crosslinking is regulated in tendon will better inform tissue engineering and regenerative therapies aimed at restoring the mechanical function of damaged tendons.
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Affiliation(s)
- A.J. Ellingson
- Chemical and Biological Engineering, University of Idaho, Moscow, ID, USA
| | - N.M. Pancheri
- Chemical and Biological Engineering, University of Idaho, Moscow, ID, USA
| | - N.R. Schiele
- Chemical and Biological Engineering, University of Idaho, Moscow, ID, USA,Address for correspondence: Nathan R. Schiele, Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MS 0904, Moscow, ID, USA. Telephone number: 208 8859063
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Xie WQ, He M, He YQ, Yu DJ, Jin HF, Yu F, Li YS. The effects of posterior cruciate ligament rupture on the biomechanical and histological characteristics of the medial collateral ligament: an animal study. J Orthop Surg Res 2021; 16:330. [PMID: 34020667 PMCID: PMC8139104 DOI: 10.1186/s13018-021-02443-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 04/22/2021] [Indexed: 12/23/2022] Open
Abstract
Background To investigate the effect of complete rupture of the posterior cruciate ligament (PCL) on the biomechanics and histology of the medial collateral ligament (MCL). Materials and methods Seventy-two male rabbits were randomly divided into two groups: the ruptured group was treated with complete PCL amputation, while the intact group was only subjected to PCL exposure without amputation. Eighteen rabbits were randomly sacrificed at 8, 16, 24, and 40 weeks after the operation, and their specimens were processed for mechanical tensile testing, nano-indentation experiments, hematoxylin-eosin (HE) staining, and picrosirius-polarization staining. Results There was no significant difference in the length and maximum displacement of the MCL between the ruptured group and the intact group at each time point. The maximum load of the ruptured group was significantly smaller than that of the intact group at 40 W. The elastic modulus and micro-hardness of the ruptured group increased significantly at 24 W and decreased significantly at 40 W. At 16 W and 24 W after PCL rupture, the number of type I collagen fibers and type III collagen fibers in the MCL of the ruptured group was significantly increased compared with that of the intact group. While the type I collagen fibers of the ruptured group were significantly decreased compared with the intact group at 40 W, there was no significant difference in type III collagen fibers between the ruptured group and the intact group. Conclusion PCL rupture has no significant effect on the mechanical and histological properties of MCL in a short period of time under physiological loading, but the histological and mechanical properties of MCL decrease with time.
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Affiliation(s)
- Wen-Qing Xie
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Miao He
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Yu-Qiong He
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Deng-Jie Yu
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Hong-Fu Jin
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China
| | - Fang Yu
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
| | - Yu-Sheng Li
- Department of Orthopaedics, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
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Cardona-Ramirez S, Stoker AM, Cook JL, Ma R. Fibroblasts From Common Anterior Cruciate Ligament Tendon Grafts Exhibit Different Biologic Responses to Mechanical Strain. Am J Sports Med 2021; 49:215-225. [PMID: 33259232 DOI: 10.1177/0363546520971852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Different tendons are chosen for anterior cruciate ligament (ACL) reconstruction based on perceived advantages and disadvantages, yet there is a relative paucity of information regarding biologic responsiveness of commonly used tendon grafts to mechanical strain. PURPOSE To evaluate the in vitro responses of graft fibroblasts derived from tendons used for ACL reconstruction to clinically relevant strain levels. STUDY DESIGN Controlled laboratory study. METHODS Twelve quadriceps tendons (QTs), 12 patellar tendons (PTs), and 9 hamstring tendons (HTs) were harvested from skeletally mature dogs (n = 16). Tendon fibroblasts were isolated and seeded onto BioFlex plates (1 × 105 cells/well). Cells were subjected to 3 strain conditions (stress deprivation, 0%; physiologic, 4%; high, 10%) for 5 days. Media were collected for proinflammatory and metabolic assays. RNA was extracted for gene expression analysis using real-time reverse transcription polymerase chain reaction. RESULTS Stress deprivation elicited significantly higher metabolic activity from HT and PT cells than from QT cells (P < .001 and P = .001, respectively). There were no differences in metabolic activity among all 3 graft fibroblasts at physiologic and high strain. COL-1 expression was significantly higher in PT versus HT during physiologic strain (P = .007). No significant differences with COL-3 expression were seen. TIMP-1 (P = .01) expression was higher in PT versus HT under physiologic strain. Scleraxis expression was higher in PT versus HT (P = .007) under physiologic strain. A strain-dependent increase in PGE2 levels occurred for all grafts. At physiologic strain conditions, HT produced significantly higher levels of PGE2 versus QT (P < .001) and PT (P = .005). CONCLUSION Fibroblasts from common ACL graft tissues exhibited different metabolic responses to mechanical strain. On the basis of these data, we conclude that early production of extracellular matrix and proinflammatory responses from ACL grafts are dependent on mechanical loading and graft source. CLINICAL RELEVANCE Graft-specific differences in ACL reconstruction outcomes are known to exist. Our results suggest that there are differences in the biologic responsiveness of cells from the tendon grafts used in ACL reconstruction, which are dependent on strain levels and graft source. The biologic properties of the tissue used for ACL reconstruction should be considered when selecting graft source.
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Affiliation(s)
- Sebastian Cardona-Ramirez
- Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - Aaron M Stoker
- Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - James L Cook
- Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
| | - Richard Ma
- Department of Orthopaedic Surgery, Thompson Laboratory for Regenerative Orthopaedics, University of Missouri, Columbia, Missouri, USA
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Chen J, Sheng D, Ying T, Zhao H, Zhang J, Li Y, Xu H, Chen S. MOFs-Based Nitric Oxide Therapy for Tendon Regeneration. NANO-MICRO LETTERS 2020; 13:23. [PMID: 34138189 PMCID: PMC8187533 DOI: 10.1007/s40820-020-00542-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 09/29/2020] [Indexed: 05/06/2023]
Abstract
Tendon regeneration is still a great challenge due to its avascular structure and low self-renewal capability. The nitric oxide (NO) therapy emerges as a promising treatment for inducing the regeneration of injured tendon by angiogenesis. Here, in this study, a system that NO-loaded metal-organic frameworks (MOFs) encapsulated in polycaprolactone (PCL)/gelatin (Gel) aligned coaxial scaffolds (NMPGA) is designed and prepared for tendon repair. In this system, NO is able to be released in vitro at a slow and stable average speed of 1.67 nM h-1 as long as 15 d without a burst release stage in the initial 48 h. Furthermore, NMPGA can not only improve the tubular formation capability of endothelial cells in vitro but also obviously increase the blood perfusion near the injured tendon in vivo, leading to accelerating the maturity of collagen and recovery of biomechanical strength of the regenerated tendon tissue. As a NO-loaded MOFs therapeutic system, NMPGA can promote tendon regeneration in a shorter healing period with better biomechanical properties in comparison with control group by angiogenesis. Therefore, this study not only provides a promising scaffold for tendon regeneration, but also paves a new way to develop a NO-based therapy for biomedical application in the future.
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Affiliation(s)
- Jun Chen
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - Dandan Sheng
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - Ting Ying
- College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Haojun Zhao
- Department of Ultrasound, Jing'an District Center Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - Jian Zhang
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - Yunxia Li
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China
| | - He Xu
- College of Chemistry and Materials Science, Shanghai Normal University, Shanghai, 200234, People's Republic of China.
| | - Shiyi Chen
- Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, People's Republic of China.
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Wei S, Gao L, Wu C, Qin F, Yuan J. Role of the lysyl oxidase family in organ development (Review). Exp Ther Med 2020; 20:163-172. [PMID: 32536990 PMCID: PMC7282176 DOI: 10.3892/etm.2020.8731] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/02/2020] [Indexed: 02/05/2023] Open
Abstract
Lysyl oxidase proteins (LOXs) are amine oxidases, which are mainly located in smooth muscle cells and fibroblasts and serve an important role in the formation of the extracellular matrix (ECM) in a copper-dependent manner. Owing to the ability of LOX proteins to modulate crosslinking between collagens and to promote the deposition of other fibers, they serve crucially in organogenesis and the subsequent organ development, as well as disease initiation and progression. In addition, ECM formation significantly influences organ morphological formation in both cancer- and non-tumor-related diseases, in addition to cellular epigenetic transformation and migration, under the influence of LOXs. A number of different signaling pathways regulate the LOXs expression and their enzymatic activation. The tissue remodeling and transformation process shares some resemblance between oncogenesis and embryogenesis. Additionally the roles that LOXs serve appeared to be stressed during oncogenesis and tumor metastasis. It has also been indicated LOXs have a noteworthy role in non-tumor diseases. Nonetheless, the role of LOXs in systemic or local organ development and disease control remains unknown. In the present study, the essential roles that LOXs play in embryogenesis were unveiled partially, whereas the role of LOXs in organ or systematic development requires further investigations. The present review aimed to discuss the roles of members of the LOX family in the context of the remodeling of organogenesis and organ development. In addition, the consequences of the malfunction of these proteins related to the development of abnormalities and resulting diseases is discussed.
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Affiliation(s)
- Shanzun Wei
- Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Liang Gao
- Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Changjing Wu
- Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Feng Qin
- Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jiuhong Yuan
- Andrology Laboratory, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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Ryu K, Saito M, Kurosaka D, Kitasato S, Omori T, Hayashi H, Kayama T, Marumo K. Enhancement of tendon-bone interface healing and graft maturation with cylindrical titanium-web (TW) in a miniature swine anterior cruciate ligament reconstruction model: histological and collagen-based analysis. BMC Musculoskelet Disord 2020; 21:198. [PMID: 32234036 PMCID: PMC7110724 DOI: 10.1186/s12891-020-03199-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 03/10/2020] [Indexed: 12/11/2022] Open
Abstract
Background Tendon-bone interface healing and ligamentization of the graft in anterior cruciate ligament (ACL) reconstruction with autografts are important factors affecting treatment outcome. This study aimed to investigate the effectiveness of a cylindrical titanium-web (TW) in tendon-bone interface healing and graft maturation in ACL reconstruction. Methods Fourteen mature female CLAWN miniature swine underwent bilateral ACL reconstructions with patellar tendon (PT) autografts. In one limb, the TW/tendon complex was placed into the proximal side of the tibial tunnel. Only the graft was transplanted into the tunnel in the control limb. The proximal side of the graft was sutured into the stump of the native ACL and the distal end was stapled to the tibia. The animals were euthanized at 4 and 15 weeks postoperatively, for histological and biochemical analyses. Results Microscopic images in TW limbs showed that ingrowth of tendon-like tissue and mineralized bone tissue into the TW connected the bone and the tendon directly. In contrast, fibrous tissue intervened between the bone and tendon in the control limbs. The total amount of collagen cross-links (which defines the strength of collagen fibers) and the maturation of collagen cross-links in TW tendons were significantly higher (p < 0.05) than those of control limbs. There was no significant difference in the ratio of dihydroxy-lysinonorleucine to hydroxy-lysinonorleucine (an indicator of tissue specific collagen maturation) between TW tendons and that of the native PT. Conclusions TW promoted the maturation and formation of collagen cross-links in the grafted tendon while maintaining the cross-links pattern of native tendon collagen, and enabled direct binding of tendon to bone.
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Affiliation(s)
- Keisho Ryu
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan.
| | - Mitsuru Saito
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Daisaburo Kurosaka
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Seiichiro Kitasato
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Toshiyuki Omori
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Hiroteru Hayashi
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Tomohiro Kayama
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
| | - Keishi Marumo
- Department of Orthopaedic Surgery, The Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Tokyo, Minato-ku, 105-8461, Japan
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Gögele C, Hahn J, Elschner C, Breier A, Schröpfer M, Prade I, Meyer M, Schulze-Tanzil G. Enhanced Growth of Lapine Anterior Cruciate Ligament-Derived Fibroblasts on Scaffolds Embroidered from Poly(l-lactide- co-ε-caprolactone) and Polylactic Acid Threads Functionalized by Fluorination and Hexamethylene Diisocyanate Cross-Linked Collagen Foams. Int J Mol Sci 2020; 21:E1132. [PMID: 32046263 PMCID: PMC7037627 DOI: 10.3390/ijms21031132] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/26/2020] [Accepted: 02/02/2020] [Indexed: 11/24/2022] Open
Abstract
Reconstruction of ruptured anterior cruciate ligaments (ACLs) is limited by the availability and donor site morbidity of autografts. Hence, a tissue engineered graft could present an alternative in the future. This study was undertaken to determine the performance of lapine (L) ACL-derived fibroblasts on embroidered poly(l-lactide-co-ε-caprolactone) (P(LA-CL)) and polylactic acid (PLA) scaffolds in regard to a tissue engineering approach for ACL reconstruction. Surface modifications of P(LA-CL)/PLA by gas-phase fluorination and cross-linking of a collagen foam using either ethylcarbodiimide (EDC) or hexamethylene diisocyanate (HMDI) were tested regarding their influence on cell adhesion, growth and gene expression. The experiments were performed using embroidered P(LA-CL)/PLA scaffolds that were seeded dynamically or statically with LACL-derived fibroblasts. Scaffold cytocompatibility, cell survival, numbers, metabolic activity, ultrastructure and sulfated glycosaminoglycan (sGAG) synthesis were evaluated. Quantitative real-time polymerase chain reaction (QPCR) revealed gene expression of collagen type I (COL1A1), decorin (DCN), tenascin C (TNC), Mohawk (MKX) and tenomodulin (TNMD). All tested scaffolds were highly cytocompatible. A significantly higher cellularity and larger scaffold surface areas colonized by cells were detected in HMDI cross-linked and fluorinated scaffolds compared to those cross-linked with EDC or without any functionalization. By contrast, sGAG synthesis was higher in controls. Despite the fact that the significance level was not reached, gene expressions of ligament extracellular matrix components and differentiation markers were generally higher in fluorinated scaffolds with cross-linked collagen foams. LACL-derived fibroblasts maintained their differentiated phenotype on fluorinated scaffolds supplemented with a HMDI cross-linked collagen foam, making them a promising tool for ACL tissue engineering.
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Affiliation(s)
- Clemens Gögele
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Nuremberg and Salzburg, Prof. Ernst Nathan Str. 1, 90419 Nuremberg, Germany;
- Department of Biosciences, Paris Lodron University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Judith Hahn
- Leibniz-Institut für Polymerforschung Dresden e. V. (IPF), Dresden, Hohe Straße 6, 01069 Dresden, Germany; (J.H.); (C.E.); (A.B.)
| | - Cindy Elschner
- Leibniz-Institut für Polymerforschung Dresden e. V. (IPF), Dresden, Hohe Straße 6, 01069 Dresden, Germany; (J.H.); (C.E.); (A.B.)
| | - Annette Breier
- Leibniz-Institut für Polymerforschung Dresden e. V. (IPF), Dresden, Hohe Straße 6, 01069 Dresden, Germany; (J.H.); (C.E.); (A.B.)
| | - Michaela Schröpfer
- Forschungsinstitut für Leder und Kunststoffbahnen (FILK), Meißner Ring 1-5, 09599 Freiberg, Germany; (M.S.); (I.P.); (M.M.)
| | - Ina Prade
- Forschungsinstitut für Leder und Kunststoffbahnen (FILK), Meißner Ring 1-5, 09599 Freiberg, Germany; (M.S.); (I.P.); (M.M.)
| | - Michael Meyer
- Forschungsinstitut für Leder und Kunststoffbahnen (FILK), Meißner Ring 1-5, 09599 Freiberg, Germany; (M.S.); (I.P.); (M.M.)
| | - Gundula Schulze-Tanzil
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Nuremberg and Salzburg, Prof. Ernst Nathan Str. 1, 90419 Nuremberg, Germany;
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Liu Z, Li Y, Ren Y, Jin Y, Yang J, Wang S, Zhu X, Xiong H, Zou G, Liu Y, Huang W. Enhancement of in vitro proliferation and bioactivity of human anterior cruciate ligament fibroblasts using an in situ tissue isolation method and basic fibroblast growth factor culture conditions: A pilot analysis. Medicine (Baltimore) 2019; 98:e15907. [PMID: 31145353 PMCID: PMC6708876 DOI: 10.1097/md.0000000000015907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Previous studies have reported poor proliferation and bioactivity of human anterior cruciate ligament fibroblasts (hACLFs) after injury. As hACLFs are one of the most significant and indispensable source of seed cells in constructing tissue-engineered ligament, enhancing hACLF proliferation would offer favorable cellular-biological ability and induce the extracellular matrix secretion of hACLFs after loading on multiple types of scaffolds. Enhancing the bioactivity of hACLFs would improve tissue repair and functional recovery after tissue-engineered ligament transplantation. This study compared cells prepared by collagenase digestion and the in situ culture of tissue pieces and investigated the effect of basic fibroblast growth factor (bFGF) on hACLFs. METHODS Six adult patients participated in this study. Of these patients, tissues from three were compared after culture establishment through collagenase digestion or in situ tissue isolation. hACLF phenotypic characteristics were assessed, and the effect of bFGF on hACLF cultures was observed. hACLFs cultured with and without bFGF served as the experimental and control groups, respectively. Cell Counting Kit-8 was used to detect proliferation. The expression of ligament-related genes and proteins was evaluated by immunofluorescence staining, real-time polymerase chain reaction (PCR) assays, and Western blot assays. RESULTS The morphology of hACLFs isolated using the two methods differed after the 2nd passage. The proliferation of cells obtained by in situ culture was higher than that of cells obtained by collagenase digestion. hACLFs cultured with bFGF after the 3rd passage exhibited a higher proliferation rate than the controls. Immunofluorescence staining, real-time PCR, and Western blot analysis showed a significant increase in ligament-related gene and protein expression in the hACLFs cultured with bFGF. CONCLUSIONS The in situ isolation of tissue pieces enhanced hACLF proliferation in vitro, and the hACLFs exhibited phenotypic characteristics of fibroblasts. hACLFs cultured with bFGF exhibited increased hACLF bioactivity.
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Affiliation(s)
- Ziming Liu
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University
| | - Yuwan Li
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University
| | - Youliang Ren
- Department of Orthopaedic Surgery, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Ying Jin
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Jibin Yang
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Shengmin Wang
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Xizhong Zhu
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Huazhang Xiong
- Department of Orthopaedic Surgery, the Second Affiliated Hospital of Chongqing Medical University, Chongqing
| | - Gang Zou
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Yi Liu
- Department of Orthopaedic Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, P.R. China
| | - Wei Huang
- Department of Orthopaedic Surgery, the First Affiliated Hospital of Chongqing Medical University
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12
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Chen B, Zhang J, Nie D, Zhao G, Fu FH, Wang JHC. Characterization of the structure of rabbit anterior cruciate ligament and its stem/progenitor cells. J Cell Biochem 2019; 120:7446-7457. [PMID: 30387227 DOI: 10.1002/jcb.28019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/15/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND It is known that anterior cruciate ligament (ACL) of the knee joint is prone to injuries with poor healing potential. The healing capacity of a tissue-like ACL is dependent on its structural components and the properties of the stem cells (SCs). Therefore, this study aimed to characterize the structure of ACL tissue and the properties of the SCs derived from the tissue components. METHODS The tissue structure of rabbit ACL was determined using a scanning electron microscope, hematoxylin and eosin, and immunohistochemical staining. The biological properties of SCs derived from the structural components of ACL were studied by colony formation, cell proliferation assay, SC marker expression and collagen exhibition, and multidifferentiation potential. RESULTS The two distinct components of ACL are classified as sheath and core, which possess differential properties in terms of collagen type, organization, and presence of blood vessels. The sheath tissue contains vascular SCs and the core tissue contains ligamentous SCs, respectively. The two types of SCs differ in clonogenicity, proliferation, and multidifferentiation potential. CONCLUSION This study shows that ACL consists of sheath and core tissues, which contain sheath and core SCs with distinctive biological properties. These findings highlight the need for use of both sheath and core SCs to promote the repair of the complex structure of injured ACL.
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Affiliation(s)
- Biao Chen
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Orthopaedic Surgery, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Jianying Zhang
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Daibang Nie
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Guangyi Zhao
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Freddie H Fu
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - James H-C Wang
- MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
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13
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Abstract
The hierarchical structure of tendon allows for attenuation of mechanical strain down decreasing length scales. While reorganization of collagen fibers accounts for microscale strain attenuation, cross-linking between collagen molecules contributes to deformation mechanisms at the fibrillar and molecular scales. Divalent and trivalent enzymatic cross-links form during the development of collagen fibrils through the enzymatic activity of lysyl oxidase (LOX). By establishing connections between telopeptidyl and triple-helical domains of adjacent molecules within collagen fibrils, these cross-links stiffen the fibrils by resisting intermolecular sliding. Ultimately, greater enzymatic cross-linking leads to less compliant and stronger tendon as a result of stiffer fibrils. In contrast, nonenzymatic cross-links such as glucosepane and pentosidine are not produced during development but slowly accumulate through glycation of collagen. Therefore, these cross-links are only expected to be present in significant quantities in advanced age, where there has been sufficient time for glycation to occur, and in diabetes, where the presence of more free sugar in the extracellular matrix increases the rate of glycation. Unlike enzymatic cross-links, current evidence suggests that nonenzymatic cross-links are at least partially isolated to the surface of collagen fibers. As a result, glycation has been proposed to primarily impact tendon mechanics by altering molecular interactions at the fiber interface, thereby diminishing sliding between fibers. Thus, increased nonenzymatic cross-linking decreases microscale strain attenuation and the viscous response of tendon. In conclusion, enzymatic and nonenzymatic collagen cross-links have demonstrable and distinct effects on the mechanical properties of tendon across different length scales.
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Affiliation(s)
- Jeremy D Eekhoff
- a Department of Biomedical Engineering , Washington University in St. Louis , St. Louis , USA
| | - Fei Fang
- b Department of Orthopedic Surgery , Columbia University , New York , USA
| | - Spencer P Lake
- a Department of Biomedical Engineering , Washington University in St. Louis , St. Louis , USA.,c Department of Mechanical Engineering and Materials Science , Washington University in St. Louis , St. Louis , USA.,d Department of Orthopaedic Surgery , Washington University in St. Louis , St. Louis , USA
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14
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Narayanan G, Bhattacharjee M, Nair LS, Laurencin CT. Musculoskeletal Tissue Regeneration: the Role of the Stem Cells. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2017. [DOI: 10.1007/s40883-017-0036-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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15
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A comparative study of effect of autograft compared with allograft anterior cruciate ligament reconstruction on expressions of LOXs and MMPs. Biosci Rep 2017; 37:BSR20160533. [PMID: 28275205 PMCID: PMC5408659 DOI: 10.1042/bsr20160533] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 02/21/2017] [Accepted: 03/08/2017] [Indexed: 02/07/2023] Open
Abstract
The present study aimed to compare the effect of autograft or allograft anterior cruciate ligament (ACL) reconstruction on the expressions of lipoxygenases (LOXs) and matrix metalloproteinases (MMPs) in a New Zealand white rabbit model. New Zealand white rabbits were divided randomly into control, sham, autograft and allograft groups. At the 4th and 8th week after operation, biomechanical testing was performed to measure the primary length, cross-sectional area, maximum tensile load and stiffness of ACL, and HE staining was used to observe cell morphology and fibre alignment of ACL. At the 2nd, 4th and 8th week after operation, quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry were applied to detect LOXs and MMPs expressions, and expressions of adenomatous polyposis coli (APC)/Wnt signalling pathway-related proteins. At the 4th and 8th week after operation, the maximum tensile load and stiffness were higher in the autograft group than in the allograft group, and the values at the 8th week were higher than those at the 4th week after operation. The fibroblast proliferation in the allograft group was more significant than that in the autograft group. Compared with the control group, LOXs and MMPs expressions and the positive expression rates of LOXs and MMPs proteins were elevated, and the values in the allograft group were higher than those in the autograft group at all time points. At 8th week after operation, compared with the autograft group, Wnt expression was higher and APC expression was lower in the allograft group. Autograft and allograft ACL reconstruction can promote LOXs and MMPs expressions by activating the APC/Wnt signalling pathway.
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16
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Different combinations of growth factors for the tenogenic differentiation of bone marrow mesenchymal stem cells in monolayer culture and in fibrin-based three-dimensional constructs. Differentiation 2017; 95:44-53. [PMID: 28319735 DOI: 10.1016/j.diff.2017.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/13/2017] [Accepted: 03/06/2017] [Indexed: 12/22/2022]
Abstract
Tendon injuries are severe burdens in clinics. The poor tendon healing is related to an ineffective response of resident cells and inadequate vascularization. Thanks to the high proliferation and multi-lineage differentiation capability, bone marrow-derived mesenchymal stem cells (BMSCs) are a promising cell source to support the tendon repair. To date, the association of various growth factors to induce the in vitro tenogenic differentiation of multipotent progenitor cells is poorly investigated. This study aimed to investigate the tenogenic differentiation of rabbit BMSCs by testing the combination of bone morphogenetic proteins (BMP-12 and 14) with transforming growth factor beta (TGF-β) and vascular endothelial growth factor (VEGF) both in 2D and 3D cultures within fibrin-based constructs. After 7 and 14 days, the tenogenic differentiation was assessed by analyzing cell metabolism and collagen content, the gene expression of tenogenic markers and the histological cell distribution and collagen deposition within 3D constructs. Our results demonstrated that the association of BMP-14 with TGF-β3 and VEGF enhanced the BMSC tenogenic differentiation both in 2D and 3D cultures. This study supports the use of fibrin as hydrogel-based matrix to generate spheroids loaded with tenogenic differentiated BMSCs that could be used to treat tendon lesions in the future.
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17
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Dex S, Lin D, Shukunami C, Docheva D. Tenogenic modulating insider factor: Systematic assessment on the functions of tenomodulin gene. Gene 2016; 587:1-17. [PMID: 27129941 DOI: 10.1016/j.gene.2016.04.051] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/20/2016] [Accepted: 04/25/2016] [Indexed: 02/08/2023]
Abstract
Tenomodulin (TNMD, Tnmd) is a gene highly expressed in tendon known to be important for tendon maturation with key implications for the residing tendon stem/progenitor cells as well as for the regulation of endothelial cell migration in chordae tendineae cordis in the heart and in experimental tumour models. This review aims at providing an encompassing overview of this gene and its protein. In addition, its known expression pattern as well as putative signalling pathways will be described. A chronological overview of the discovered functions of this gene in tendon and other tissues and cells is provided as well as its use as a tendon and ligament lineage marker is assessed in detail and discussed. Last, information about the possible connections between TNMD genomic mutations and mRNA expression to various diseases is delivered. Taken together this review offers a solid synopsis on the up-to-date information available about TNMD and aids at directing and focusing the future research to fully uncover the roles and implications of this interesting gene.
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Affiliation(s)
- Sarah Dex
- Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Dasheng Lin
- Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Chisa Shukunami
- Department of Molecular Biology and Biochemistry, Division of Basic Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Denitsa Docheva
- Experimental Surgery and Regenerative Medicine, Department of Surgery, Ludwig-Maximilians-University (LMU), Munich, Germany; Department of Medical Biology, Medical University-Plovdiv, Plovdiv, Bulgaria.
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18
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Belangero PS, Leal MF, Cohen C, Figueiredo EA, Smith MC, Andreoli CV, de Castro Pochini A, Ejnisman B, Cohen M. Expression analysis of genes involved in collagen cross-linking and its regulation in traumatic anterior shoulder instability. J Orthop Res 2016; 34:510-7. [PMID: 26185036 DOI: 10.1002/jor.22984] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/14/2015] [Indexed: 02/04/2023]
Abstract
The molecular alterations involved in the capsule deformation presented in shoulder instability patients are poorly understood. Increased TGFβ1 acts as a signal for production of matrix macromolecules by fibrogenic cells at joint injury sites. TGFβ1, through its receptor TGFβR1, regulates genes involved in collagen cross-linking, such as LOX, PLOD1, and PLOD2. We evaluated TGFβ1, TGFβR1, LOX, PLOD1, and PLOD2 gene expression in the antero-inferior (macroscopically injured region), antero-superior and posterior regions of the glenohumeral capsule of 29 shoulder instability patients and eight controls. We observed that PLOD2 expression was increased in the anterior-inferior capsule region of the patients compared to controls. LOX expression tended to be increased in the posterior portion of patients. Patients with recurrent shoulder dislocation presented upregulation of TGFβR1 in the antero-inferior capsule portion and of PLOD2 in the posterior region. Conversely, LOX was increased in the posterior portion of the capsule of patients with a single shoulder dislocation episode. In the antero-inferior, LOX expression was inversely correlated and TGFβR1 was directly correlated with the duration of symptoms. In the posterior region, PLOD2, TGFβ1, and TGFβR1 were directly correlated with the duration of symptoms. In conclusion, PLOD2 expression was increased in the macroscopically injured region of the capsule of patients. Upregulation of TGFβ1, TGFβR1, and PLOD2 seems to be related with the maintenance of disease symptoms, especially in the posterior region. LOX upregulation seems to occur only in the initial phase of the affection. Therefore, TGFβ1, TGFβR1, LOX, and PLOD2 may play a role in shoulder instability.
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Affiliation(s)
- Paulo Santoro Belangero
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
| | - Mariana Ferreira Leal
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil.,Disciplina de Genética, Departamento de Morfologia e Genética, Universidade Federal de São Paulo, São Paulo, São Paulo, 04023-001, Brazil
| | - Carina Cohen
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
| | - Eduardo Antônio Figueiredo
- Disciplina de Genética, Departamento de Morfologia e Genética, Universidade Federal de São Paulo, São Paulo, São Paulo, 04023-001, Brazil
| | - Marília Cardoso Smith
- Disciplina de Genética, Departamento de Morfologia e Genética, Universidade Federal de São Paulo, São Paulo, São Paulo, 04023-001, Brazil
| | - Carlos Vicente Andreoli
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
| | - Alberto de Castro Pochini
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
| | - Benno Ejnisman
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
| | - Moises Cohen
- Departamento de Ortopedia e Traumatologia, Universidade Federal de São Paulo, São Paulo, São Paulo, 04038-031, Brazil
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19
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Hoyer M, Meier C, Breier A, Hahner J, Heinrich G, Drechsel N, Meyer M, Rentsch C, Garbe LA, Ertel W, Lohan A, Schulze-Tanzil G. In vitro characterization of self-assembled anterior cruciate ligament cell spheroids for ligament tissue engineering. Histochem Cell Biol 2014; 143:289-300. [PMID: 25256666 DOI: 10.1007/s00418-014-1280-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2014] [Indexed: 01/14/2023]
Abstract
Tissue engineering of an anterior cruciate ligament (ACL) implant with functional enthesis requires site-directed seeding of different cell types on the same scaffold. Therefore, we studied the suitability of self-assembled three-dimensional spheroids generated by lapine ACL ligament fibroblasts for directed scaffold colonization. The spheroids were characterized in vitro during 14 days in static and 7 days in dynamic culture. Size maintenance of self-assembled spheroids, the vitality, the morphology and the expression pattern of the cells were monitored. Additionally, we analyzed the total sulfated glycosaminoglycan, collagen contents and the expression of the ligament components type I collagen, decorin and tenascin C on protein and for COL1A1, DCN and TNMD on gene level in the spheroids. Subsequently, the cell colonization of polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) polymer scaffolds was assessed in response to a directed, spheroid-based seeding technique. ACL cells were able to self-assemble spheroids and survive over 14 days. The spheroids decreased in size but not in cellularity depending on the culture time and maintained or even increased their differentiation state. The area of P[LA-CL] scaffolds, colonized after 14 days by the cells of one spheroid, was in average 4.57 ± 2.3 mm(2). Scaffolds consisting of the polymer P[LA-CL] were more suitable for colonization by spheroids than PDS embroideries. We conclude that ACL cell spheroids are suitable as site-directed seeding strategy for scaffolds in ACL tissue engineering approaches and recommend the use of freshly assembled spheroids for scaffold colonization, due to their balanced proliferation and differentiation.
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Affiliation(s)
- M Hoyer
- Department of Orthopaedic, Trauma and Reconstructive Surgery, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, FEM, Garystrasse 5, 14195, Berlin, Germany
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20
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Abstract
Diabetes increases risk of fracture, although type 2 diabetes is characterized by normal or high bone mineral density (BMD) compared with the patients without diabetes. The fracture risk of type 1 diabetes as well as type 2 diabetes increases beyond an explained by a decrease of BMD. Thus, diabetes may reduce bone strength without change in BMD. Whole bone strength is determined by bone density, structure, and quality, which encompass the micro-structural and tissue material properties. Recent literature showed that diabetes reduces bone material properties rather than BMD. Collagen intermolecular cross-linking plays an important role in the expression of bone strength. Collagen cross-links can be divided into beneficial enzymatic immature divalent and mature trivalent cross-links and disadvantageous nonenzymatic cross-links (Advanced glycation end products: AGEs) induced by glycation and oxidation. The formation pathway and biological function are quite different. Not only hyperglycemia, but also oxidative stress induces the reduction in enzymatic cross-links and the formation of AGEs. In this review, we describe the mechanism of low bone quality in diabetes and the usefulness of the measurement of plasma or urinary level of AGEs for estimation of fracture risk.
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Affiliation(s)
- Mitsuru Saito
- Department of Orthopaedic Surgery, Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo, 105-8461, Japan,
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