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Mora KE, Mlawer SJ, Loiselle AE, Buckley MR. The Micromechanical Environment of the Impinged Achilles Tendon. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2401015. [PMID: 38966889 DOI: 10.1002/smll.202401015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 06/13/2024] [Indexed: 07/06/2024]
Abstract
Although tendon predominantly experiences longitudinal tensile forces, transverse forces due to impingement from bone are implicated in both physiological and pathophysiological processes. However, prior studies have not characterized the micromechanical strain environment in the context of tendon impingement. To address this knowledge gap, mouse hindlimb explants are imaged on a multiphoton microscope, and image stacks of the same population of tendon cells are obtained in the Achilles tendon before and after dorsiflexion-induced impingement by the heel bone. Based on the acquired images, multiaxial strains are measured at the extracellular matrix (ECM), pericellular matrix (PCM), and cell scales. Impingement generated substantial transverse compression at the matrix-scale, which led to longitudinal stretching of cells, increased cell aspect ratio, and enormous volumetric compression of the PCM. These experimental results are corroborated by a finite element model, which further demonstrated that impingement produces high cell surface stresses and strains that greatly exceed those brought about by longitudinal tension. Moreover, in both experiments and simulations, impingement-generated microscale stresses and strains are highly dependent on initial cell-cell gap spacing. Identifying factors that influence the microscale strain environment generated by impingement could contribute to a more mechanistic understanding of impingement-induced tendinopathies.
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Affiliation(s)
- Keshia E Mora
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY, 14642, USA
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Samuel J Mlawer
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
| | - Alayna E Loiselle
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Mark R Buckley
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, 14627, USA
- Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY, 14642, USA
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2
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Aggouras AN, Stowe EJ, Mlawer SJ, Connizzo BK. Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling. J Biomech Eng 2024; 146:071009. [PMID: 38584416 PMCID: PMC11080950 DOI: 10.1115/1.4065270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/09/2024]
Abstract
Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration are poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found that 1% cyclic strain best maintains native physiology while promoting extracellular matrix (ECM) turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has a significant impact on understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.
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Affiliation(s)
- Anthony N. Aggouras
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
- Boston University
| | - Emma J. Stowe
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
| | - Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
- Boston University
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02115
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3
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Mlawer SJ, Frank EH, Connizzo BK. Aged tendons lack adaptive response to acute compressive injury. J Orthop Res 2024; 42:973-984. [PMID: 38041209 PMCID: PMC11009076 DOI: 10.1002/jor.25752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/24/2023] [Accepted: 11/29/2023] [Indexed: 12/03/2023]
Abstract
Rotator cuff tendinopathy has a multifactorial etiology, with both aging and external compression found to influence disease progression. However, tendon's response to these factors is still poorly understood and in vivo animal models make it difficult to decouple these effects. Therefore, we developed an explant culture model that allows us to directly apply compression to tendons and then observe their biological responses. Using this model, we applied a single acute compressive injury to C57BL/6J flexor digitorum longus tendon explants and observed changes in viability, metabolic activity, matrix composition, matrix biosynthesis, matrix structure, gene expression, and mechanical properties. We hypothesized that a single acute compressive load would result in an injury response in tendon and that this effect would be amplified in aged tendons. We found that young tendons had increased matrix turnover with a decrease in small leucine-rich proteoglycans, increase in compression-resistant proteoglycan aggrecan, increase in collagen synthesis, and an upregulation of collagen-degrading MMP-9. Aged tendons lacked any of these adaptive responses and instead had decreased metabolic activity and collagen synthesis. This implies that aged tendons lack the adaptation mechanisms required to return to homeostasis, and therefore are at greater risk for compression-induced injury. Overall, we present a novel compressive injury model that demonstrates lasting age-dependent changes and has the potential to examine the long-term response of tendon to a variety of compressive loading conditions.
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Affiliation(s)
- Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, United States
| | - Eliot H. Frank
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, United States
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4
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Aggouras AN, Stowe EJ, Mlawer SJ, Connizzo BK. Aged Tendons Exhibit Altered Mechanisms of Strain-Dependent Extracellular Matrix Remodeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577397. [PMID: 38352312 PMCID: PMC10862756 DOI: 10.1101/2024.01.26.577397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
Aging is a primary risk factor for degenerative tendon injuries, yet the etiology and progression of this degeneration is poorly understood. While aged tendons have innate cellular differences that support a reduced ability to maintain mechanical tissue homeostasis, the response of aged tendons to altered levels of mechanical loading has not yet been studied. To address this question, we subjected young and aged murine flexor tendon explants to various levels of in vitro tensile strain. We first compared the effect of static and cyclic strain on matrix remodeling in young tendons, finding that cyclic strain is optimal for studying remodeling in vitro. We then investigated the remodeling response of young and aged tendon explants after 7 days of varied mechanical stimulus (stress-deprivation, 1%, 3%, 5%, or 7% cyclic strain) via assessment of tissue composition, biosynthetic capacity, and degradation profiles. We hypothesized that aged tendons would show muted adaptive responses to changes in tensile strain and exhibit a shifted mechanical setpoint, at which the remodeling balance is optimal. Interestingly, we found 1% cyclic strain best maintains native physiology while promoting ECM turnover for both age groups. However, aged tendons display fewer strain-dependent changes, suggesting a reduced ability to adapt to altered levels of mechanical loading. This work has significant impact in understanding the regulation of tissue homeostasis in aged tendons, which can inform clinical rehabilitation strategies for treating elderly patients.
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Affiliation(s)
- Anthony N. Aggouras
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Emma J. Stowe
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Samuel J. Mlawer
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
| | - Brianne K. Connizzo
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA., 44 Cummington Mall, Boston, Massachusetts, USA, 02115
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5
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Marvin JC, Brakewood ME, Poon MLS, Andarawis-Puri N. Regenerative MRL/MpJ tendon cells exhibit sex differences in morphology, proliferation, mechanosensitivity, and cell-ECM organization. J Orthop Res 2023; 41:2273-2286. [PMID: 37004178 DOI: 10.1002/jor.25562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/10/2023] [Accepted: 03/24/2023] [Indexed: 04/03/2023]
Abstract
Clinical and animal studies have reported the influence of sex on the incidence and progression of tendinopathy, which results in disparate structural and biomechanical outcomes. However, there remains a paucity in our understanding of the sex-specific biological mechanisms underlying effective tendon healing. To overcome this hurdle, our group has investigated the impact of sex on tendon regeneration using the super-healer Murphy Roths Large (MRL/MpJ) mouse strain. We have previously shown that the scarless healing capacity of MRL/MpJ patellar tendons is associated with sexually dimorphic regulation of gene expression for pathways involved in fibrosis, cell migration, adhesion, and extracellular matrix (ECM) remodeling following an acute mid-substance injury. Thus, we hypothesized that MRL/MpJ scarless tendon healing is mediated by sex-specific and temporally distinct orchestration of cell-ECM interactions. Accordingly, the present study comparatively evaluated MRL/MpJ tendon cells on two-dimensional (2D; glass) and scaffold platforms to examine cell behavior under biochemical and topographical cues associated with tendon homeostasis and healing. Female MRL/MpJ cells showed reduced 2D migration and spreading area accompanied by enhanced mechanosensing, ECM alignment, and fibronectin-mediated cell proliferation compared to male MRL/MpJ cells. Interestingly, female MRL/MpJ cells cultured on isotropic scaffolds showed diminished cell-ECM organization compared to male MRL/MpJ cells. Lastly, MRL/MpJ cells elicited enhanced cytoskeletal elongation and alignment, ECM deposition and organization, and connexin 43-mediated intercellular communication compared to male B6 cells, regardless of culture condition or sex. These results provide insight into the cellular features conserved within the MRL/MpJ phenotype and potential sex-specific targets for the development of more equitable therapeutics.
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Affiliation(s)
- Jason C Marvin
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Molly E Brakewood
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Mong L S Poon
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
| | - Nelly Andarawis-Puri
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
- Hospital for Special Surgery, New York, New York, USA
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Chatterjee M, Evans MK, Bell R, Nguyen PK, Kamalitdinov TB, Korntner S, Kuo CK, Dyment NA, Andarawis-Puri N. Histological and immunohistochemical guide to tendon tissue. J Orthop Res 2023; 41:2114-2132. [PMID: 37321983 DOI: 10.1002/jor.25645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 06/02/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023]
Abstract
Tendons are unique dense connective tissues with discrete zones having specific structure and function. They are juxtaposed with other tissues (e.g., bone, muscle, and fat) with different compositional, structural, and mechanical properties. Additionally, tendon properties change drastically with growth and development, disease, aging, and injury. Consequently, there are unique challenges to performing high quality histological assessment of this tissue. To address this need, histological assessment was one of the breakout session topics at the 2022 Orthopaedic Research Society (ORS) Tendon Conference hosted at the University of Pennsylvania. The purpose of the breakout session was to discuss needs from members of the ORS Tendon Section related to histological procedures, data presentation, knowledge dissemination, and guidelines for future work. Therefore, this review provides a brief overview of the outcomes of this discussion and provides a set of guidelines, based on the perspectives from our laboratories, for histological assessment to assist researchers in their quest to utilize these techniques to enhance the outcomes and interpretations of their studies.
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Affiliation(s)
- Monideepa Chatterjee
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Mary K Evans
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rebecca Bell
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
| | - Phong K Nguyen
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
| | - Timur B Kamalitdinov
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stefanie Korntner
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
| | - Catherine K Kuo
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland, USA
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, New York, USA
- Department of Orthopaedics, University of Maryland Medical Center, Baltimore, Maryland, USA
| | - Nathaniel A Dyment
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nelly Andarawis-Puri
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York, USA
- Hospital for Special Surgery, New York, New York, USA
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Mousavizadeh R, West VC, Inguito KL, Elliott DM, Parreno J. The application of mechanical load onto mouse tendons by magnetic restraining represses Mmp-3 expression. BMC Res Notes 2023; 16:127. [PMID: 37391824 PMCID: PMC10314558 DOI: 10.1186/s13104-023-06413-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 06/20/2023] [Indexed: 07/02/2023] Open
Abstract
OBJECTIVES Mechanical loading is crucial for tendon matrix homeostasis. Under-stimulation of tendon tissue promotes matrix degradation and ultimately tendon failure. In this study, we examined the expression of tendon matrix molecules and matrix-degrading enzymes (matrix metalloproteinases) in stress-deprived tail tendons and compared to tendons that were mechanically loaded by a simple restraining method. DATA DESCRIPTION Isolated mouse tail fascicles were either floated or restrained by magnets in cell culture media for 24 h. The gene expression of tendon matrix molecules and matrix metalloproteinases in the tendon fascicles of mouse tails were examined by real-time RT-PCR. Stress deprivation of tail tendons increase Mmp3 mRNA levels. Restraining tendons represses these increases in Mmp3. The gene expression response to restraining was specific to Mmp3 at 24 h as we did not observe mRNA level changes in other matrix related genes that we examined (Col1, Col3, Tnc, Acan, and Mmp13). To elucidate, the mechanisms that may regulate load transmission in tendon tissue, we examined filamentous (F-)actin staining and nuclear morphology. As compared to stress deprived tendons, restrained tendons had greater staining for F-actin. The nuclei of restrained tendons are smaller and more elongated. These results indicate that mechanical loading regulates specific gene expression potentially through F-actin regulation of nuclear morphology. A further understanding on the mechanisms involved in regulating Mmp3 gene expression may lead to new strategies to prevent tendon degeneration.
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Affiliation(s)
- Rouhollah Mousavizadeh
- Department of Physical Therapy, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - Valerie C West
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA
| | - Kameron L Inguito
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Dawn M Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA
| | - Justin Parreno
- Department of Biomedical Engineering, University of Delaware, Newark, DE, USA.
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.
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Calderan L, Carton F, Andreana I, Bincoletto V, Arpicco S, Stella B, Malatesta M. An ex vivo experimental system to track fluorescent nanoparticles inside skeletal muscle. Eur J Histochem 2022; 67:3596. [PMID: 36546417 PMCID: PMC9827424 DOI: 10.4081/ejh.2023.3596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
The development of novel nanoconstructs for biomedical applications requires the assessment of their biodistribution, metabolism and clearance in single cells, organs and entire organisms in a living environment. To reduce the number of in vivo experiments performed and to refine the methods used, in accordance with the 3Rs principle, this work proposes an ex vivo experimental system to monitor, using fluorescence microscopy, the distribution of nanoparticles in explanted murine skeletal muscle maintained in a bioreactor that can preserve the structural and functional features of the organ for long periods of time. Fluorescently-labelled liposomes and poly(lactide-co-glycolide) (PLGA)-based nanoparticles were injected into the intact soleus muscle (in the distal region close to the tendon) immediately after explants, and their distribution was analysed at increasing incubation times in cross cryosections from the proximal region of the belly. Both nanocarriers were clearly recognized in the muscle and were found to enter and migrate inside the myofibres, whereas their migration in the connective tissue seemed to be limited. In addition, some fluorescent signals were observed inside the macrophages, demonstrating the physiological clearance of the nanocarriers that did not enter the myofibres. Our ex vivo system therefore provides more information than previous in vitro experiments on cultured muscle cells, highlighting the need for the appropriate functionalization of nanocarriers if myofibre targeting is to be improved.
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Affiliation(s)
- Laura Calderan
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona
| | - Flavia Carton
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona,*Present address: Department of Health Sciences, University of Piemonte Orientale “A. Avogadro”, Novara, Italy
| | - Ilaria Andreana
- Department of Drug Science and Technology, University of Turin, Italy
| | | | - Silvia Arpicco
- Department of Drug Science and Technology, University of Turin, Italy
| | - Barbara Stella
- Department of Drug Science and Technology, University of Turin, Italy
| | - Manuela Malatesta
- Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona,Correspondence: Prof. Manuela Malatesta, Department of Neurosciences, Biomedicine and Movement Sciences, Anatomy and Histology Section, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy. Tel. +39.045.8027569. .
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Inguito KL, Schofield MM, Faghri AD, Bloom ET, Heino M, West VC, Ebron KMM, Elliott DM, Parreno J. Stress deprivation of tendon explants or Tpm3.1 inhibition in tendon cells reduces F-actin to promote a tendinosis-like phenotype. Mol Biol Cell 2022; 33:ar141. [PMID: 36129771 PMCID: PMC9727789 DOI: 10.1091/mbc.e22-02-0067] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Actin is a central mediator between mechanical force and cellular phenotype. In tendons, it is speculated that mechanical stress deprivation regulates gene expression by reducing filamentous (F)-actin. However, the mechanisms regulating tenocyte F-actin remain unclear. Tropomyosins (Tpms) are master regulators of F-actin. There are more than 40 Tpm isoforms, each having the unique capability to stabilize F-actin subpopulations. We investigated F-actin polymerization in stress-deprived tendons and tested the hypothesis that stress fiber-associated Tpm(s) stabilize F-actin to regulate cellular phenotype. Stress deprivation of mouse tail tendon down-regulated tenogenic and up-regulated protease (matrix metalloproteinase-3) mRNA levels. Concomitant with mRNA modulation were increases in G/F-actin, confirming reduced F-actin by tendon stress deprivation. To investigate the molecular regulation of F-actin, we identified that tail, Achilles, and plantaris tendons express three isoforms in common: Tpm1.6, 3.1, and 4.2. Tpm3.1 associates with F-actin in native and primary tenocytes. Tpm3.1 inhibition reduces F-actin, leading to decreases in tenogenic expression, increases in chondrogenic expression, and enhancement of protease expression in mouse and human tenocytes. These expression changes by Tpm3.1 inhibition are consistent with tendinosis progression. A further understanding of F-actin regulation in musculoskeletal cells could lead to new therapeutic interventions to prevent alterations in cellular phenotype during disease progression.
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Affiliation(s)
- Kameron L. Inguito
- Departments of Biological Sciences, University of Delaware, Newark, DE 19716
| | - Mandy M. Schofield
- Departments of Biological Sciences, University of Delaware, Newark, DE 19716
| | - Arya D. Faghri
- Departments of Biological Sciences, University of Delaware, Newark, DE 19716
| | - Ellen T. Bloom
- Biomedical Engineering, University of Delaware, Newark, DE 19716
| | - Marissa Heino
- Departments of Biological Sciences, University of Delaware, Newark, DE 19716,Biomedical Engineering, University of Delaware, Newark, DE 19716
| | - Valerie C. West
- Biomedical Engineering, University of Delaware, Newark, DE 19716
| | | | - Dawn M. Elliott
- Biomedical Engineering, University of Delaware, Newark, DE 19716
| | - Justin Parreno
- Departments of Biological Sciences, University of Delaware, Newark, DE 19716,Biomedical Engineering, University of Delaware, Newark, DE 19716,*Address correspondence to: Justin Parreno ()
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Pentzold S, Wildemann B. Mechanical overload decreases tenogenic differentiation compared to physiological load in bioartificial tendons. J Biol Eng 2022; 16:5. [PMID: 35241113 PMCID: PMC8896085 DOI: 10.1186/s13036-022-00283-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 02/10/2022] [Indexed: 01/18/2023] Open
Abstract
Background Tenocytes as specialised fibroblasts and inherent cells of tendons require mechanical load for their homeostasis. However, how mechanical overload compared to physiological load impacts on the tenogenic differentiation potential of fibroblasts is largely unknown. Methods Three-dimensional bioartificial tendons (BATs) seeded with murine fibroblasts (cell line C3H10T1/2) were subjected to uniaxial sinusoidal elongation at either overload conditions (0–16%, Ø 8%) or physiological load (0–8%, Ø 4%). This regime was applied for 2 h a day at 0.1 Hz for 7 days. Controls were unloaded, but under static tension. Results Cell survival did not differ among overload, physiological load and control BATs. However, gene expression of tenogenic and extra-cellular matrix markers (Scx, Mkx, Tnmd, Col1a1 and Col3a1) was significantly decreased in overload versus physiological load and controls, respectively. In contrast, Mmp3 was significantly increased at overload compared to physiological load, and significantly decreased under physiological load compared to controls. Mkx and Tnmd were significantly increased in BATs subjected to physiological load compared to controls. Proinflammatory interleukin-6 showed increased protein levels comparing load (both over and physiological) versus unloaded controls. Alignment of the cytoskeleton in strain direction was decreased in overload compared to physiological load, while other parameters such as nuclear area, roundness or cell density were less affected. Conclusions Mechanical overload decreases tenogenic differentiation and increases ECM remodelling/inflammation in 3D-stimulated fibroblasts, whereas physiological load may induce opposite effects. Supplementary Information The online version contains supplementary material available at 10.1186/s13036-022-00283-y.
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Affiliation(s)
- Stefan Pentzold
- Experimental Trauma Surgery, Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747, Jena, Germany.
| | - Britt Wildemann
- Experimental Trauma Surgery, Department of Trauma, Hand and Reconstructive Surgery, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747, Jena, Germany
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11
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Wu SY, Kim W, Kremen TJ. In Vitro Cellular Strain Models of Tendon Biology and Tenogenic Differentiation. Front Bioeng Biotechnol 2022; 10:826748. [PMID: 35242750 PMCID: PMC8886160 DOI: 10.3389/fbioe.2022.826748] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/17/2022] [Indexed: 11/19/2022] Open
Abstract
Research has shown that the surrounding biomechanical environment plays a significant role in the development, differentiation, repair, and degradation of tendon, but the interactions between tendon cells and the forces they experience are complex. In vitro mechanical stimulation models attempt to understand the effects of mechanical load on tendon and connective tissue progenitor cells. This article reviews multiple mechanical stimulation models used to study tendon mechanobiology and provides an overview of the current progress in modelling the complex native biomechanical environment of tendon. Though great strides have been made in advancing the understanding of the role of mechanical stimulation in tendon development, damage, and repair, there exists no ideal in vitro model. Further comparative studies and careful consideration of loading parameters, cell populations, and biochemical additives may further offer new insight into an ideal model for the support of tendon regeneration studies.
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Affiliation(s)
- Shannon Y. Wu
- David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
| | - Won Kim
- Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Thomas J. Kremen
- Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
- *Correspondence: Thomas J. Kremen Jr,
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Pedaprolu K, Szczesny S. A Novel, Open Source, Low-Cost Bioreactor for Load-Controlled Cyclic Loading of Tendon Explants. J Biomech Eng 2022; 144:1135618. [PMID: 35147179 DOI: 10.1115/1.4053795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Indexed: 11/08/2022]
Abstract
A major risk factor for tendinopathy is tendon overuse (i.e., fatigue loading). Fatigue loading of tendon damages the extracellular matrix and induces tissue degeneration. However, the specific mechanisms linking tendon fatigue damage with tissue degeneration are unclear. While explant models of tendon fatigue loading have been used to address this knowledge gap, they predominantly employ bioreactors that apply cyclic displacements/strains rather than loads/stresses, which are more physiologically relevant. This is because of the technical complexity and cost of building a load-controlled bioreactor, which requires multiple motors, load cells, and computationally intensive feedback loops. Here, we present a novel, low-cost, load-controlled bioreactor that applies cyclic loading to multiple tendon explants by offloading weights from a single motorized stage. Using an optional load cell, we validated that the bioreactor can effectively provide load-controlled fatigue testing of mouse and rat tendon explants while maintaining tissue viability. Furthermore, all the design files, bill of materials, and operating software are available "open source" (https://github.com/Szczesnytendon/Bioreactor) so that anyone can easily manufacture and use the bioreactor for their own research. Therefore, this novel load-controlled bioreactor will enable researchers to study the mechanisms driving fatigue-induced tendon degeneration in a more physiologically relevant and cost-effective manner.
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Affiliation(s)
- Krishna Pedaprolu
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, Pennsylvania State University, CBE Building Suite 122, University Park, PA 16802
| | - Spencer Szczesny
- Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, Department of Orthopaedics and Rehabilitation, Pennsylvania State University, Hershey, Pennsylvania, Pennsylvania State University, CBE Building Suite 122, University Park, PA 16802
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13
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Shear-stress sensing by PIEZO1 regulates tendon stiffness in rodents and influences jumping performance in humans. Nat Biomed Eng 2021; 5:1457-1471. [PMID: 34031557 PMCID: PMC7612848 DOI: 10.1038/s41551-021-00716-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 03/17/2021] [Indexed: 01/31/2023]
Abstract
Athletic performance relies on tendons, which enable movement by transferring forces from muscles to the skeleton. Yet, how load-bearing structures in tendons sense and adapt to physical demands is not understood. Here, by performing calcium (Ca2+) imaging in mechanically loaded tendon explants from rats and in primary tendon cells from rats and humans, we show that tenocytes detect mechanical forces through the mechanosensitive ion channel PIEZO1, which senses shear stresses induced by collagen-fibre sliding. Through tenocyte-targeted loss-of-function and gain-of-function experiments in rodents, we show that reduced PIEZO1 activity decreased tendon stiffness and that elevated PIEZO1 mechanosignalling increased tendon stiffness and strength, seemingly through upregulated collagen cross-linking. We also show that humans carrying the PIEZO1 E756del gain-of-function mutation display a 13.2% average increase in normalized jumping height, presumably due to a higher rate of force generation or to the release of a larger amount of stored elastic energy. Further understanding of the PIEZO1-mediated mechanoregulation of tendon stiffness should aid research on musculoskeletal medicine and on sports performance.
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14
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Stauber T, Wolleb M, Duss A, Jaeger PK, Heggli I, Hussien AA, Blache U, Snedeker JG. Extrinsic Macrophages Protect While Tendon Progenitors Degrade: Insights from a Tissue Engineered Model of Tendon Compartmental Crosstalk. Adv Healthc Mater 2021; 10:e2100741. [PMID: 34494401 DOI: 10.1002/adhm.202100741] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/30/2021] [Indexed: 12/15/2022]
Abstract
Tendons are among the most mechanically stressed tissues of the body, with a functional core of type-I collagen fibers maintained by embedded stromal fibroblasts known as tenocytes. The intrinsic load-bearing core compartment of tendon is surrounded, nourished, and repaired by the extrinsic peritendon, a synovial-like tissue compartment with access to tendon stem/progenitor cells as well as blood monocytes. In vitro tendon model systems generally lack this important feature of tissue compartmentalization, while in vivo models are cumbersome when isolating multicellular mechanisms. To bridge this gap, an improved in vitro model of explanted tendon core stromal tissue (mouse tail tendon fascicles) surrounded by cell-laden collagen hydrogels that mimic extrinsic tissue compartments is suggested. Using this model, CD146+ tendon stem/progenitor cell and CD45+ F4/80+ bone-marrow derived macrophage activity within a tendon injury-like niche are recapitulated. It is found that extrinsic stromal progenitors recruit to the damaged core, contribute to an overall increase in catabolic ECM gene expression, and accelerate the decrease in mechanical properties. Conversely, it is found that extrinsic bone-marrow derived macrophages in these conditions adopt a proresolution phenotype that mitigates rapid tissue breakdown by outwardly migrated tenocytes and F4/80+ "tenophages" from the intrinsic tissue core.
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Affiliation(s)
- Tino Stauber
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
| | - Maja Wolleb
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
| | - Anja Duss
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
| | - Patrick K. Jaeger
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
| | - Irina Heggli
- Center of Experimental Rheumatology Department of Rheumatology University Hospital, University of Zurich Lengghalde 5 Zurich 8008 Switzerland
| | - Amro A. Hussien
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
| | - Ulrich Blache
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
- Fraunhofer Institute for Cell Therapy and Immunology 04103 Leipzig Germany
| | - Jess G. Snedeker
- Department of Orthopedics Balgrist University Hospital University of Zurich Lengghalde 5 Zurich 8008 Switzerland
- Institute for Biomechanics ETH Zurich Zurich 8093 Switzerland
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15
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van Vijven M, Wunderli SL, Ito K, Snedeker JG, Foolen J. Serum deprivation limits loss and promotes recovery of tenogenic phenotype in tendon cell culture systems. J Orthop Res 2021; 39:1561-1571. [PMID: 32478872 PMCID: PMC8359397 DOI: 10.1002/jor.24761] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/28/2020] [Accepted: 05/25/2020] [Indexed: 02/04/2023]
Abstract
Current knowledge gaps on tendon tissue healing can partly be ascribed to the limited availability of physiologically relevant culture models. An unnatural extracellular matrix, high serum levels and random cell morphology in vitro mimic strong vascularization and lost cell elongation in pathology, and discord with a healthy, in vivo cell microenvironment. The thereby induced phenotypic drift in tendon-derived cells (TDCs) compromises the validity of the research model. Therefore, this research quantified the extracellular matrix (ECM)-, serum-, and cell morphology-guided phenotypic changes in tendon cells of whole tendon fascicle explants with intact ECM and TDCs cultured in a controlled microenvironmental niche. Explanted murine tail tendon fascicles were cultured in serum-rich or serum-free medium and phenotype was assessed using transcriptome analysis. Next, phenotypic marker gene expression was measured in in vitro expanded murine tail TDCs upon culture in serum-rich or serum-free medium on aligned or random collagen I patterns. Freshly isolated fascicles or TDCs served as native controls. In both systems, the majority of tendon-specific genes were similarly attenuated in serum-rich culture. Strikingly, 1-week serum-deprived culture-independent of cell morphology-converged TDC gene expression toward native levels. This study reveals a dynamic serum-responsive tendon cell phenotype. Extracting fascicles or TDCs from their native environment causes large changes in cellular phenotype, which can be limited and even reversed by serum deprivation. We conclude that serum-derived factors override matrix-integrity and cell morphology cues and that serum-deprivation stimulates a more physiological microenvironment for in vitro studies.
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Affiliation(s)
- Marc van Vijven
- Orthopaedic Biomechanics, Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
| | - Stefania L. Wunderli
- Orthopaedic Biomechanics LaboratoryUniversity Hospital Balgrist, University of ZurichZürichSwitzerland
- Institute for Biomechanics, ETH ZurichZürichSwitzerland
| | - Keita Ito
- Orthopaedic Biomechanics, Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
| | - Jess G. Snedeker
- Orthopaedic Biomechanics LaboratoryUniversity Hospital Balgrist, University of ZurichZürichSwitzerland
- Institute for Biomechanics, ETH ZurichZürichSwitzerland
| | - Jasper Foolen
- Orthopaedic Biomechanics, Department of Biomedical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
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16
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Blache U, Wunderli SL, Hussien AA, Stauber T, Flückiger G, Bollhalder M, Niederöst B, Fucentese SF, Snedeker JG. Inhibition of ERK 1/2 kinases prevents tendon matrix breakdown. Sci Rep 2021; 11:6838. [PMID: 33767224 PMCID: PMC7994809 DOI: 10.1038/s41598-021-85331-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 02/26/2021] [Indexed: 12/14/2022] Open
Abstract
Tendon extracellular matrix (ECM) mechanical unloading results in tissue degradation and breakdown, with niche-dependent cellular stress directing proteolytic degradation of tendon. Here, we show that the extracellular-signal regulated kinase (ERK) pathway is central in tendon degradation of load-deprived tissue explants. We show that ERK 1/2 are highly phosphorylated in mechanically unloaded tendon fascicles in a vascular niche-dependent manner. Pharmacological inhibition of ERK 1/2 abolishes the induction of ECM catabolic gene expression (MMPs) and fully prevents loss of mechanical properties. Moreover, ERK 1/2 inhibition in unloaded tendon fascicles suppresses features of pathological tissue remodeling such as collagen type 3 matrix switch and the induction of the pro-fibrotic cytokine interleukin 11. This work demonstrates ERK signaling as a central checkpoint to trigger tendon matrix degradation and remodeling using load-deprived tissue explants.
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Affiliation(s)
- Ulrich Blache
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Stefania L Wunderli
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Amro A Hussien
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Tino Stauber
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Gabriel Flückiger
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Maja Bollhalder
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Barbara Niederöst
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Sandro F Fucentese
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Jess G Snedeker
- Department of Orthopedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
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17
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Siadat SM, Zamboulis DE, Thorpe CT, Ruberti JW, Connizzo BK. Tendon Extracellular Matrix Assembly, Maintenance and Dysregulation Throughout Life. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1348:45-103. [PMID: 34807415 DOI: 10.1007/978-3-030-80614-9_3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In his Lissner Award medal lecture in 2000, Stephen Cowin asked the question: "How is a tissue built?" It is not a new question, but it remains as relevant today as it did when it was asked 20 years ago. In fact, research on the organization and development of tissue structure has been a primary focus of tendon and ligament research for over two centuries. The tendon extracellular matrix (ECM) is critical to overall tissue function; it gives the tissue its unique mechanical properties, exhibiting complex non-linear responses, viscoelasticity and flow mechanisms, excellent energy storage and fatigue resistance. This matrix also creates a unique microenvironment for resident cells, allowing cells to maintain their phenotype and translate mechanical and chemical signals into biological responses. Importantly, this architecture is constantly remodeled by local cell populations in response to changing biochemical (systemic and local disease or injury) and mechanical (exercise, disuse, and overuse) stimuli. Here, we review the current understanding of matrix remodeling throughout life, focusing on formation and assembly during the postnatal period, maintenance and homeostasis during adulthood, and changes to homeostasis in natural aging. We also discuss advances in model systems and novel tools for studying collagen and non-collagenous matrix remodeling throughout life, and finally conclude by identifying key questions that have yet to be answered.
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Affiliation(s)
| | - Danae E Zamboulis
- Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK
| | - Chavaunne T Thorpe
- Comparative Biomedical Sciences, The Royal Veterinary College, University of London, London, UK
| | - Jeffrey W Ruberti
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Brianne K Connizzo
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
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18
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Dyment NA, Barrett JG, Awad H, Bautista CA, Banes A, Butler DL. A brief history of tendon and ligament bioreactors: Impact and future prospects. J Orthop Res 2020; 38:2318-2330. [PMID: 32579266 PMCID: PMC7722018 DOI: 10.1002/jor.24784] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/28/2020] [Accepted: 06/12/2020] [Indexed: 02/04/2023]
Abstract
Bioreactors are powerful tools with the potential to model tissue development and disease in vitro. For nearly four decades, bioreactors have been used to create tendon and ligament tissue-engineered constructs in order to define basic mechanisms of cell function, extracellular matrix deposition, tissue organization, injury, and tissue remodeling. This review provides a historical perspective of tendon and ligament bioreactors and their contributions to this advancing field. First, we demonstrate the need for bioreactors to improve understanding of tendon and ligament function and dysfunction. Next, we detail the history and evolution of bioreactor development and design from simple stretching of explants to fabrication and stimulation of two- and three-dimensional constructs. Then, we demonstrate how research using tendon and ligament bioreactors has led to pivotal basic science and tissue-engineering discoveries. Finally, we provide guidance for new basic, applied, and clinical research utilizing these valuable systems, recognizing that fundamental knowledge of cell-cell and cell-matrix interactions combined with appropriate mechanical and chemical stimulation of constructs could ultimately lead to functional tendon and ligament repairs in the coming decades.
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Affiliation(s)
- Nathaniel A. Dyment
- McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA
| | - Jennifer G. Barrett
- Department of Large Animal Clinical Sciences, Marion duPont Scott Equine Medical Center, Virginia Tech, Leesburg, VA
| | - Hani Awad
- Department of Biomedical Engineering, The Center for Musculoskeletal Research, University of Rochester, Rochester, NY 14627
| | | | - Albert Banes
- Flexcell International Corp., 2730 Tucker St., Suite 200, Burlington, 27215, NC
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC
| | - David L. Butler
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, 45221
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19
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Janvier AJ, Canty-Laird E, Henstock JR. A universal multi-platform 3D printed bioreactor chamber for tendon tissue engineering. J Tissue Eng 2020; 11:2041731420942462. [PMID: 32944210 PMCID: PMC7469720 DOI: 10.1177/2041731420942462] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/22/2020] [Indexed: 12/11/2022] Open
Abstract
A range of bioreactors use linear actuators to apply tensile forces in vitro, but differences in their culture environments can limit a direct comparison between studies. The widespread availability of 3D printing now provides an opportunity to develop a 'universal' bioreactor chamber that, with minimal exterior editing can be coupled to a wide range of commonly used linear actuator platforms, for example, the EBERS-TC3 and CellScale MCT6, resulting in a greater comparability between results and consistent testing of potential therapeutics. We designed a bioreactor chamber with six independent wells that was 3D printed in polylactic acid using an Ultimaker 2+ and waterproofed using a commercially available coating (XTC-3D), an oxirane resin. The cell culture wells were further coated with Sylgard-184 polydimethylsiloxane (PDMS) to produce a low-adhesion well surface. With appropriate coating and washing steps, all materials were shown to be non-cytotoxic by lactate dehydrogenase assay, and the bioreactor was waterproof, sterilisable and reusable. Tissue-engineered tendons were generated from human mesenchymal stem cells in a fibrin hydrogel and responded to 5% cyclic strain (0.5 Hz, 5 h/day, 21 days) in the bioreactor by increased production of collagen-Iα1 and decreased production of collagen-IIIα1. Calcification of the extracellular matrix was observed in unstretched tendon controls indicating abnormal differentiation, while tendons cultured under cyclic strain did not calcify and exhibited a tenogenic phenotype. The ease of manufacturing this bioreactor chamber enables researchers to quickly and cheaply reproduce this culture environment for use with many existing bioreactor actuator platforms by downloading the editable CAD files from a public database and following the manufacturing steps we describe.
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Affiliation(s)
- Adam J Janvier
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | | | - James R Henstock
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
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20
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Michel PA, Kronenberg D, Neu G, Stolberg-Stolberg J, Frank A, Pap T, Langer M, Fehr M, Raschke MJ, Stange R. Microsurgical reconstruction affects the outcome in a translational mouse model for Achilles tendon healing. J Orthop Translat 2020; 24:1-11. [PMID: 32489862 PMCID: PMC7260609 DOI: 10.1016/j.jot.2020.04.003] [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: 12/13/2019] [Revised: 03/17/2020] [Accepted: 04/08/2020] [Indexed: 01/02/2023] Open
Abstract
Background Animal models are one of the first steps in translation of basic science findings to clinical practice. For tendon healing research, transgenic mouse models are important to advance therapeutic strategies. However, the small size of the structures complicates surgical approaches, histological assessment, and biomechanical testing. In addition, available models are not standardized and difficult to compare. How surgery itself affects the healing outcome has not been investigated yet. The focus of the study was to develop a procedure that includes a transection and microsurgical reconstruction of the Achilles tendon but, unlike other models, preserves the sciatic nerve. We wanted to examine how distinct parts of the technique influenced healing. Methods For this animal model study, we used 96 wild-type male C57BL/6 mice aged 8–12 weeks. We evaluated different suture techniques and macroscopically confirmed the optimal combination of suture material and technique to minimize tendon gap formation. A key element is the detailed, step-by-step illustration of the surgery. In addition, we assessed histological (Herovici and Alcian blue staining) outcome parameters at 1–16 weeks postoperatively. Microcomputed tomography (micro-CT) was performed to measure the bone volume of heterotopic ossifications (HOs). Biomechanical analyses were carried out using a viscoelastic protocol on the biomechanical testing machine LM1. Results A modified 4-strand suture combined with a cerclage for immobilization without transection of the sciatic nerve reliably eliminated gap formation. The maximal dorsal extension of the hindlimb at the upper ankle joint from the equinus position (limited by the immobilization cerclage) increased over time postoperatively (operation: 28.8 ± 2.2°; 1 week: 54 ± 36°; 6 weeks: 80 ± 11.7°; 16 weeks: 96 ± 15.8°, p > 0.05). Histological staining revealed a maturation of collagen fibres within 6 weeks, whereas masses of cartilage were visible throughout the healing period. Micro-CT scans detected the development of HOs starting at 4 weeks and further progression at 6 and 16 weeks (bone volume, 4 weeks: 0.07604 ± 0.05286 mm3; 6 weeks: 0.50682 ± 0.68841 mm3; 16 weeks: 2.36027 ± 0.85202 mm3, p > 0.001). In-depth micro-CT analysis of the different surgical elements revealed that an injury of the tendon is a key factor for the development of HOs. Immobilization alone does not trigger HOs. Biomechanical properties of repaired tendons were greatly altered and remained inferior 6 weeks after surgery. Conclusion With this study, we demonstrated that the microsurgical technique greatly influences the short- and longer-term healing outcome. When the sciatic nerve is preserved, the best surgical reconstruction of the tendon defect is achieved by a 4-strand core suture in combination with a tibiofibular cerclage for postoperative immobilization. The cerclage promotes a gradual increase in the range of motion of the upper ankle joint, comparable with an early mobilization rehabilitation protocol. HO, as a key mechanism for poor tendon healing, is progressive and can be monitored early in the model. The translational potential of this article The study enhances the understanding of model dependent factors of healing. The described reconstruction technique provides a reproducible and translational rodent model for future Achilles tendon healing research. In combination with transgenic strains, it can be facilitated to advance therapeutic strategies to improve the clinical results of tendon injuries.
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Affiliation(s)
- Philipp A Michel
- Department of Trauma, Hand- and Reconstructive Surgery, University Hospital Muenster, Muenster, Germany
| | - Daniel Kronenberg
- Department of Regenerative Musculoskeletal Medicine, Institute of Musculoskeletal Medicine, Westfaelische Wilhelms University Muenster, Muenster, Germany
| | - Gertje Neu
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Josef Stolberg-Stolberg
- Department of Trauma, Hand- and Reconstructive Surgery, University Hospital Muenster, Muenster, Germany
| | - Andre Frank
- Department of Trauma, Hand- and Reconstructive Surgery, University Hospital Muenster, Muenster, Germany
| | - Thomas Pap
- Institute of Musculoskeletal Medicine, Westfaelische Wilhelms University Muenster, Muenster, Germany
| | - Martin Langer
- Department of Trauma, Hand- and Reconstructive Surgery, University Hospital Muenster, Muenster, Germany
| | - Michael Fehr
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Michael J Raschke
- Department of Trauma, Hand- and Reconstructive Surgery, University Hospital Muenster, Muenster, Germany
| | - Richard Stange
- Department of Regenerative Musculoskeletal Medicine, Institute of Musculoskeletal Medicine, Westfaelische Wilhelms University Muenster, Muenster, Germany
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21
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Schoenenberger AD, Tempfer H, Lehner C, Egloff J, Mauracher M, Bird A, Widmer J, Maniura-Weber K, Fucentese SF, Traweger A, Silvan U, Snedeker JG. Macromechanics and polycaprolactone fiber organization drive macrophage polarization and regulate inflammatory activation of tendon in vitro and in vivo. Biomaterials 2020; 249:120034. [PMID: 32315865 DOI: 10.1016/j.biomaterials.2020.120034] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/04/2020] [Accepted: 04/05/2020] [Indexed: 12/16/2022]
Abstract
Appropriate macrophage response to an implanted biomaterial is crucial for successful tissue healing outcomes. In this work we investigated how intrinsic topological cues from electrospun biomaterials and extrinsic mechanical loads cooperate to guide macrophage activation and macrophage-tendon fibroblast cross-talk. We performed a series of in vitro and in vivo experiments using aligned or randomly oriented polycaprolactone nanofiber substrates in both mechanically loaded and unloaded conditions. Across all experiments a disorganized biomaterial fiber topography was alone sufficient to promote a pro-inflammatory signature in macrophages, tendon fibroblasts, and tendon tissue. Extrinsic mechanical loading was found to strongly regulate the character of this signature by reducing pro-inflammatory markers both in vitro and in vivo. We observed that macrophages generally displayed a stronger response to biophysical cues than tendon fibroblasts, with dominant effects of cross-talk between these cell types observed in mechanical co-culture models. Collectively our data suggest that macrophages play a potentially important role as mechanosensory cells in tendon repair, and provide insight into how biological response might be therapeutically modulated by rational biomaterial designs that address the biomechanical niche of recruited cells.
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Affiliation(s)
- Angelina D Schoenenberger
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Herbert Tempfer
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University - Spinal Cord Injury & Tissue Regeneration Center Salzburg, Salzburg, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Christine Lehner
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University - Spinal Cord Injury & Tissue Regeneration Center Salzburg, Salzburg, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Jasmin Egloff
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Marita Mauracher
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Anna Bird
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Jonas Widmer
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Katharina Maniura-Weber
- Biointerfaces, Empa, Swiss Federal Laboratories for Material Science and Technology, St. Gallen, Switzerland
| | - Sandro F Fucentese
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland
| | - Andreas Traweger
- Institute of Tendon and Bone Regeneration, Paracelsus Medical University - Spinal Cord Injury & Tissue Regeneration Center Salzburg, Salzburg, Austria; Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Unai Silvan
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Jess G Snedeker
- Department of Orthopedics, Balgrist Hospital, University of Zurich, Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
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22
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Wunderli SL, Blache U, Beretta Piccoli A, Niederöst B, Holenstein CN, Passini FS, Silván U, Bundgaard L, Auf dem Keller U, Snedeker JG. Tendon response to matrix unloading is determined by the patho-physiological niche. Matrix Biol 2020; 89:11-26. [PMID: 31917255 DOI: 10.1016/j.matbio.2019.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/20/2022]
Abstract
Although the molecular mechanisms behind tendon disease remain obscure, aberrant stromal matrix turnover and tissue hypervascularity are known hallmarks of advanced tendinopathy. We harness a tendon explant model to unwind complex cross-talk between the stromal and vascular tissue compartments. We identify the hypervascular tendon niche as a state-switch that gates degenerative matrix remodeling within the tissue stroma. Here pathological conditions resembling hypervascular tendon disease provoke rapid cell-mediated tissue breakdown upon mechanical unloading, in contrast to unloaded tendons that remain functionally stable in physiological low-oxygen/-temperature niches. Analyses of the stromal tissue transcriptome and secretome reveal that a stromal niche with elevated tissue oxygenation and temperature drives a ROS mediated cellular stress response that leads to adoption of an immune-modulatory phenotype within the degrading stromal tissue. Degradomic analysis further reveals a surprisingly rich set of active matrix proteases behind the progressive loss of tissue mechanics. We conclude that the tendon stromal compartment responds to aberrant mechanical unloading in a manner that is highly dependent on the vascular niche, with ROS gating a complex proteolytic breakdown of the functional collagen backbone.
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Affiliation(s)
- Stefania L Wunderli
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Ulrich Blache
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Agnese Beretta Piccoli
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Barbara Niederöst
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Claude N Holenstein
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Fabian S Passini
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Unai Silván
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland
| | - Louise Bundgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Denmark
| | - Ulrich Auf dem Keller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Denmark
| | - Jess G Snedeker
- University Hospital Balgrist, University of Zurich, Switzerland; Institute for Biomechanics, ETH Zurich, Switzerland.
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Connizzo BK, Grodzinsky AJ. Release of pro-inflammatory cytokines from muscle and bone causes tenocyte death in a novel rotator cuff in vitro explant culture model. Connect Tissue Res 2018; 59:423-436. [PMID: 29447021 PMCID: PMC6240787 DOI: 10.1080/03008207.2018.1439486] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Tendinopathy is a significant clinical problem thought to be associated with altered mechanical loading. Explant culture models allow researchers to alter mechanical loading in a controlled in vitro environment while maintaining tenocytes in their native matrix. However, current models do not accurately represent commonly injured tendons, ignoring contributions of associated musculature and bone, as well as regional collagen structure. This study details the characterization of amouse rotator cuff explant culture model, including bone, tendon, and muscle (BTM). MATERIALS AND METHODS Following harvest, BTM explants were maintained in stress-deprived culture for one week and tendon was then assessed for changes in cell viability, metabolism, matrix structure and content. RESULTS Matrix turnover occurred throughout culture as manifested in both gene expression and biosynthesis, but this did not translate to net changes in total collagen or sulfated glycosaminoglycan content. Furthermore, tendon structure was not significantly altered throughout culture. However, we found significant cell death in BTM tendons after 3 days in culture, which we hypothesize is cytokine-induced. Using a targeted multiplex assay, we found high levels of pro-inflammatory cytokines released to the culture medium from muscle and bone, levels that did cause cell deathin tendon-alone controls. CONCLUSIONS Overall, this model presents an innovative approach to understandingrotator cuff injury and tenocyte mechanobiology in a clinically-relevant tendon structure. Our model can be a powerful tool to investigate how mechanical and biological stimuli can alter normal tendon health and lead to tendon degeneration, and may provide a testbed for therapeutics for tendon repair.
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Affiliation(s)
- Brianne K. Connizzo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
| | - Alan J. Grodzinsky
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States,Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, United States,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, United States
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