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Sukhnandan R, Chen Q, Shen J, Pao S, Huan Y, Sutton GP, Gill JP, Chiel HJ, Webster-Wood VA. Full Hill-type muscle model of the I1/I3 retractor muscle complex in Aplysia californica. BIOLOGICAL CYBERNETICS 2024; 118:165-185. [PMID: 38922432 PMCID: PMC11289039 DOI: 10.1007/s00422-024-00990-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 04/22/2024] [Indexed: 06/27/2024]
Abstract
The coordination of complex behavior requires knowledge of both neural dynamics and the mechanics of the periphery. The feeding system of Aplysia californica is an excellent model for investigating questions in soft body systems' neuromechanics because of its experimental tractability. Prior work has attempted to elucidate the mechanical properties of the periphery by using a Hill-type muscle model to characterize the force generation capabilities of the key protractor muscle responsible for moving Aplysia's grasper anteriorly, the I2 muscle. However, the I1/I3 muscle, which is the main driver of retractions of Aplysia's grasper, has not been characterized. Because of the importance of the musculature's properties in generating functional behavior, understanding the properties of muscles like the I1/I3 complex may help to create more realistic simulations of the feeding behavior of Aplysia, which can aid in greater understanding of the neuromechanics of soft-bodied systems. To bridge this gap, in this work, the I1/I3 muscle complex was characterized using force-frequency, length-tension, and force-velocity experiments and showed that a Hill-type model can accurately predict its force-generation properties. Furthermore, the muscle's peak isometric force and stiffness were found to exceed those of the I2 muscle, and these results were analyzed in the context of prior studies on the I1/I3 complex's kinematics in vivo.
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Affiliation(s)
- Ravesh Sukhnandan
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA, 15213, USA
| | - Qianxue Chen
- Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Jiayi Shen
- Department of Nutrition, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Samantha Pao
- Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Yu Huan
- Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Gregory P Sutton
- School of Life and Environmental Sciences, University of Lincoln, Green Lane, Lincoln, LN67DL, UK
| | - Jeffrey P Gill
- Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Hillel J Chiel
- Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
- Department of Neurosciences, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
- Department of Biomedical Engineering, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106-7080, USA
| | - Victoria A Webster-Wood
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA, 15213, USA.
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA, 15213, USA.
- McGowan Institute for Regenerative Medicine, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA, 15213, USA.
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2
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Spadoni S, Todros S, Reggiani C, Marcucci L, Pavan PG. The role of the extracellular matrix in the reduction of lateral force transmission in muscle bundles: A finite element analysis. Comput Biol Med 2024; 175:108488. [PMID: 38653066 DOI: 10.1016/j.compbiomed.2024.108488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/28/2024] [Accepted: 04/15/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND AND OBJECTIVE Aging is associated with a reduction in muscle performance, but muscle weakness is characterized by a much greater loss of force loss compared to mass loss. The aim of this work is to assess the contribution of the extracellular matrix (ECM) to the lateral transmission of force in humans and the loss of transmitted force due to age-related modifications. METHODS Finite element models of muscle bundles are developed for young and elderly human subjects, by considering a few fibers connected through an ECM layer. Bundles of young and elderly subjects are assumed to differ in terms of ECM thickness, as observed experimentally. A three-element-based Hill model is adopted to describe the active behavior of muscle fibers, while the ECM is modeled assuming an isotropic hyperelastic neo-Hookean constitutive formulation. Numerical analyses are carried out by mimicking, at the scale of a bundle, two experimental protocols from the literature. RESULTS When comparing numerical results obtained for bundles of young and elderly subjects, a greater reduction in the total transmitted force is observed in the latter. The loss of transmitted force is 22 % for the elderly subjects, while it is limited to 7.5 % for the young subjects. The result for the elderly subjects is in line with literature studies on animal models, showing a reduction in the range of 20-34 %. This can be explained by an alteration in the mechanism of lateral force transmission due to the lower shear stiffness of the ECM in elderly subjects, related to its higher thickness. CONCLUSIONS Computational modeling allows to evaluate at the bundle level how the age-related increase of the ECM amount between fibers affects the lateral transmission of force. The results suggest that the observed increase in ECM thickness in aging alone can explain the reduction of the total transmitted force, due to the impaired lateral transmission of force of each fiber.
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Affiliation(s)
- Silvia Spadoni
- Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Silvia Todros
- Department of Industrial Engineering, University of Padova, Padova, Italy.
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Piero G Pavan
- Department of Industrial Engineering, University of Padova, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città Della Speranza, Padova, Italy
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3
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Taneja K, He X, He Q, Chen JS. A multi-resolution physics-informed recurrent neural network: formulation and application to musculoskeletal systems. COMPUTATIONAL MECHANICS 2023; 73:1125-1145. [PMID: 38699409 PMCID: PMC11060984 DOI: 10.1007/s00466-023-02403-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/21/2023] [Indexed: 05/05/2024]
Abstract
This work presents a multi-resolution physics-informed recurrent neural network (MR PI-RNN), for simultaneous prediction of musculoskeletal (MSK) motion and parameter identification of the MSK systems. The MSK application was selected as the model problem due to its challenging nature in mapping the high-frequency surface electromyography (sEMG) signals to the low-frequency body joint motion controlled by the MSK and muscle contraction dynamics. The proposed method utilizes the fast wavelet transform to decompose the mixed frequency input sEMG and output joint motion signals into nested multi-resolution signals. The prediction model is subsequently trained on coarser-scale input-output signals using a gated recurrent unit (GRU), and then the trained parameters are transferred to the next level of training with finer-scale signals. These training processes are repeated recursively under a transfer-learning fashion until the full-scale training (i.e., with unfiltered signals) is achieved, while satisfying the underlying dynamic equilibrium. Numerical examples on recorded subject data demonstrate the effectiveness of the proposed framework in generating a physics-informed forward-dynamics surrogate, which yields higher accuracy in motion predictions of elbow flexion-extension of an MSK system compared to the case with single-scale training. The framework is also capable of identifying muscle parameters that are physiologically consistent with the subject's kinematics data.
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Affiliation(s)
- Karan Taneja
- Department of Structural Engineering, University of California San Diego, La Jolla, CA USA
| | | | - QiZhi He
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, Minneapolis, MN USA
| | - Jiun-Shyan Chen
- Department of Structural Engineering, University of California San Diego, La Jolla, CA USA
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4
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Sanchez MM, Bagdasarian IA, Darch W, Morgan JT. Organotypic cultures as aging associated disease models. Aging (Albany NY) 2022; 14:9338-9383. [PMID: 36435511 PMCID: PMC9740367 DOI: 10.18632/aging.204361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 10/21/2022] [Indexed: 11/24/2022]
Abstract
Aging remains a primary risk factor for a host of diseases, including leading causes of death. Aging and associated diseases are inherently multifactorial, with numerous contributing factors and phenotypes at the molecular, cellular, tissue, and organismal scales. Despite the complexity of aging phenomena, models currently used in aging research possess limitations. Frequently used in vivo models often have important physiological differences, age at different rates, or are genetically engineered to match late disease phenotypes rather than early causes. Conversely, routinely used in vitro models lack the complex tissue-scale and systemic cues that are disrupted in aging. To fill in gaps between in vivo and traditional in vitro models, researchers have increasingly been turning to organotypic models, which provide increased physiological relevance with the accessibility and control of in vitro context. While powerful tools, the development of these models is a field of its own, and many aging researchers may be unaware of recent progress in organotypic models, or hesitant to include these models in their own work. In this review, we describe recent progress in tissue engineering applied to organotypic models, highlighting examples explicitly linked to aging and associated disease, as well as examples of models that are relevant to aging. We specifically highlight progress made in skin, gut, and skeletal muscle, and describe how recently demonstrated models have been used for aging studies or similar phenotypes. Throughout, this review emphasizes the accessibility of these models and aims to provide a resource for researchers seeking to leverage these powerful tools.
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Affiliation(s)
- Martina M. Sanchez
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | | | - William Darch
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | - Joshua T. Morgan
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
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5
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Fede C, Fan C, Pirri C, Petrelli L, Biz C, Porzionato A, Macchi V, De Caro R, Stecco C. The Effects of Aging on the Intramuscular Connective Tissue. Int J Mol Sci 2022; 23:ijms231911061. [PMID: 36232366 PMCID: PMC9569538 DOI: 10.3390/ijms231911061] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/01/2022] [Accepted: 09/18/2022] [Indexed: 11/24/2022] Open
Abstract
The intramuscular connective tissue plays a critical role in maintaining the structural integrity of the muscle and in providing mechanical support. The current study investigates age-related changes that may contribute to passive stiffness and functional impairment of skeletal muscles. Variations in the extracellular matrix in human quadriceps femoris muscles in 10 young men, 12 elderly males and 16 elderly females, and in the hindlimb muscles of 6 week old, 8 month old and 2 year old C57BL/6J male mice, were evaluated. Picrosirius red, Alcian blue and Weigert Van Gieson stainings were performed to evaluate collagen, glycosamynoglycans and elastic fibers. Immunohistochemistry analyses were carried out to assess collagen I, collagen III and hyaluronan. The percentage area of collagen was significantly higher with aging (p < 0.01 in humans, p < 0.001 in mice), mainly due to an increase in collagen I, with no differences in collagen III (p > 0.05). The percentage area of elastic fibers in the perimysium was significantly lower (p < 0.01) in elderly men, together with a significant decrease in hyaluronan content both in humans and in mice. No significant differences were detected according to gender. The accumulation of collagen I and the lower levels of hyaluronan and elastic fibers with aging could cause a stiffening of the muscles and a reduction of their adaptability.
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Affiliation(s)
- Caterina Fede
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
- Correspondence:
| | - Chenglei Fan
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Carmelo Pirri
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Lucia Petrelli
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Carlo Biz
- Department of Surgery, Oncology and Gastroenterology, Orthopedic Clinic, University of Padua, 35128 Padua, Italy
| | - Andrea Porzionato
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Veronica Macchi
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Raffaele De Caro
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
| | - Carla Stecco
- Department of Neurosciences, Institute of Human Anatomy, University of Padua, 35121 Padua, Italy
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6
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He X, Taneja K, Chen JS, Lee CH, Hodgson J, Malis V, Sinha U, Sinha S. Multiscale modeling of passive material influences on deformation and force output of skeletal muscles. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2022; 38:e3571. [PMID: 35049153 DOI: 10.1002/cnm.3571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/06/2021] [Accepted: 01/15/2022] [Indexed: 06/14/2023]
Abstract
Passive materials in human skeletal muscle tissues play an important role in force output of skeletal muscles. This paper introduces a multiscale modeling framework to investigate how age-associated variations on microscale passive muscle components, including microstructural geometry (e.g., connective tissue thickness) and material properties (e.g., anisotropy), influence the force output and deformations of the continuum skeletal muscle. We first define a representative volume element (RVE) for the microstructure of muscle and determine the homogenized macroscale mechanical properties of the RVE from the separate mechanical properties of the individual components of the RVE, including muscle fibers and connective tissue with its associated collagen fibers. The homogenized properties of the RVE are then used to define the elements of the continuum muscle model to evaluate the force output and deformations of the whole muscle. Conversely, the regional deformations of the continuum model are fed back to the RVE model to determine the responses of the individual microscale components. Simulations of muscle isometric contractions at a range of muscle lengths are performed to investigate the effects of muscle architectural changes (e.g., pennation angles) due to aging on force output and muscle deformation. The correlations between the pennation angle, the shear deformation in the microscale connective tissue (an indicator for the lateral force transmission), the angle difference between the fiber direction and principal strain direction and the resulting shear deformation at the continuum scale, as well as the force output of the skeletal muscle are also discussed.
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Affiliation(s)
- Xiaolong He
- Department of Structural Engineering, University of California San Diego, San Diego, California, USA
| | - Karan Taneja
- Department of Structural Engineering, University of California San Diego, San Diego, California, USA
| | - Jiun-Shyan Chen
- Department of Structural Engineering, University of California San Diego, San Diego, California, USA
| | - Chung-Hao Lee
- School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, Oklahoma, USA
| | - John Hodgson
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, California, USA
| | - Vadim Malis
- Department of Physics, University of California San Diego, San Diego, California, USA
- Department of Radiology, University of California San Diego, San Diego, California, USA
| | - Usha Sinha
- Department of Physics, San Diego State University, San Diego, California, USA
| | - Shantanu Sinha
- Department of Radiology, University of California San Diego, San Diego, California, USA
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7
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Single skeletal muscle fiber mechanical properties: a muscle quality biomarker of human aging. Eur J Appl Physiol 2022; 122:1383-1395. [DOI: 10.1007/s00421-022-04924-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/23/2022] [Indexed: 12/25/2022]
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8
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Frontera WR. Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning. Prog Rehabil Med 2022; 7:20220044. [PMID: 36118146 PMCID: PMC9437741 DOI: 10.2490/prm.20220044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/16/2022] [Indexed: 11/11/2022] Open
Abstract
The 20th and 21st centuries have witnessed a substantial increase in human life
expectancy and in the number of men and women aged 60 years and older. Aging is associated
with a large number of health conditions, including sarcopenia, which has been the subject
of important research in the past 30 years. Sarcopenia is characterized by an age-related
loss of muscle mass, weakness, and impaired physical performance. The condition can be
diagnosed with a combination of measurements of these three elements. The precise
definition of sarcopenia and the selection of optimal assessment methods have changed
significantly in the past 20 years; nonetheless, the prevalence of sarcopenia in the
general older population is in the range of 5–15%. Molecular and cellular events at the
muscle cell level impact the size and quality of muscles (force adjusted for size). The
active and passive mechanical properties of single muscle fibers are altered by changes in
the structure and function of various cellular elements. Systemic factors such as
inflammation, loss of hormonal influence, and deleterious lifestyle choices also
contribute to sarcopenia. The consequences of sarcopenia include many adverse effects such
as impairments in activities of daily living, falls, loss of independence, and increased
mortality. Several rehabilitative interventions have been tested, and the safest and most
effective is the use of progressive resistance exercise. An increase in dietary protein
intake has synergistic effects. Future research should focus on a consensus definition of
sarcopenia, identification of the best assessment methods, understanding of biological
mechanisms, and testing of innovative interventions.
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Affiliation(s)
- Walter R. Frontera
- Department of Physical Medicine, Rehabilitation, and Sports Medicine/Department of Physiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico, USA
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9
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Xu J, Fu SN, Hug F. Age-related increase in muscle stiffness is muscle length dependent and associated with muscle force in senior females. BMC Musculoskelet Disord 2021; 22:829. [PMID: 34579696 PMCID: PMC8477537 DOI: 10.1186/s12891-021-04519-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 07/10/2021] [Indexed: 02/08/2023] Open
Abstract
Background In aging, muscle stiffness is considered as one of the factors associated with the reduction of force generation capability. There have been inconsistent findings on age-related alteration in the passive stiffness of quadriceps muscle in the female adults. Thus, the aim of this study was to determine the effect of aging on the shear moduli of the superficial muscle heads of the quadriceps and to explore its relationship with knee extension force. Methods Passive shear moduli of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) were measured at rest using shear wave elastography in 20 young and 20 senior female adults. Measurements were repeated at four knee joint positions, that is, 30°, 60°, 90°, and 105° of knee flexion. Maximal isometric voluntary knee extension force was assessed at 30°, 60°, and 90° of knee flexion. Results As per our findings, senior adults were determined to have significantly higher passive muscle shear moduli in the RF (by 34% – 68%; all p < 0.05) and the VL muscle heads (by 13%–16%, all p < 0.05) at and beyond 60° of knee flexion. Age-related increase in the VM was evident at 105° knee flexion (by11%, p = 0.020). The RF shear modulus was negatively correlated to the maximal isometric voluntary contraction force measured at 60° (r = − 0.485, p = 0.030) in senior adults. Conclusions Senior female adults had greater passive stiffness at the superficial muscle heads of the quadriceps muscles when measured at long muscle length. Among the senior female adults, the passive stiffness of RF has been determined to have a negative association with the knee extensor force only at 60° knee flexion. No significant association was noted for other angles and muscles.
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Affiliation(s)
- Jingfei Xu
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, PR China.,Department of Rehabilitation Sciences, the Hong Kong Polytechnic University, Yuk Choi Road, Kowloon, Hong Kong, China.,Institute for Disaster Management and Reconstruction, Sichuan University, Chengdu, PR China
| | - Siu Ngor Fu
- Department of Rehabilitation Sciences, the Hong Kong Polytechnic University, Yuk Choi Road, Kowloon, Hong Kong, China.
| | - François Hug
- University of Nantes, Faculty of Sport Sciences, Laboratory "Movement, Interactions, Performance" (EA 4334), Nantes, France.,InstitutUniversitaire de France (IUF), Paris, France
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10
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Sinha U, Malis V, Chen JS, Csapo R, Kinugasa R, Narici MV, Sinha S. Role of the Extracellular Matrix in Loss of Muscle Force With Age and Unloading Using Magnetic Resonance Imaging, Biochemical Analysis, and Computational Models. Front Physiol 2020; 11:626. [PMID: 32625114 PMCID: PMC7315044 DOI: 10.3389/fphys.2020.00626] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/18/2020] [Indexed: 12/23/2022] Open
Abstract
The focus of this review is the application of advanced MRI to study the effect of aging and disuse related remodeling of the extracellular matrix (ECM) on force transmission in the human musculoskeletal system. Structural MRI includes (i) ultra-low echo times (UTE) maps to visualize and quantify the connective tissue, (ii) diffusion tensor imaging (DTI) modeling to estimate changes in muscle and ECM microstructure, and (iii) magnetization transfer contrast imaging to quantify the macromolecular fraction in muscle. Functional MRI includes dynamic acquisitions during contraction cycles enabling computation of the strain tensor to monitor muscle deformation. Further, shear strain extracted from the strain tensor may be a potential surrogate marker of lateral transmission of force. Biochemical and histological analysis of muscle biopsy samples can provide "gold-standard" validation of some of the MR findings. The review summarizes biochemical studies of ECM adaptations with age and with disuse. A brief summary of animal models is included as they provide experimental confirmation of longitudinal and lateral force transmission pathways. Computational muscle models enable exploration of force generation and force pathways and elucidate the link between structural adaptations and functional consequences. MR image findings integrated in a computational model can explain and predict subject specific functional changes to structural adaptations. Future work includes development and validation of MRI biomarkers using biochemical analysis of muscle tissue as a reference standard and potential translation of the imaging markers to the clinic to noninvasively monitor musculoskeletal disease conditions and changes consequent to rehabilitative interventions.
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Affiliation(s)
- Usha Sinha
- Department of Physics, San Diego State University, San Diego, CA, United States
| | - Vadim Malis
- Department of Physics, University of California, San Diego, San Diego, CA, United States
| | - Jiun-Shyan Chen
- Department of Structural Engineering, University of California, San Diego, San Diego, CA, United States
| | - Robert Csapo
- Research Unit for Orthopaediic Sports Medicine and Injury Prevention, ISAG, Private University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria
| | - Ryuta Kinugasa
- Department of Human Sciences, Kanagawa University, Yokohama, Japan.,Computational Engineering Applications Unit, Advanced Center for Computing and Communication, RIKEN, Saitama, Japan
| | - Marco Vincenzo Narici
- Institute of Physiology, Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Shantanu Sinha
- Department of Radiology, University of California, San Diego, San Diego, CA, United States
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11
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Marcucci L, Reggiani C. Increase of resting muscle stiffness, a less considered component of age-related skeletal muscle impairment. Eur J Transl Myol 2020. [DOI: 10.4081/ejtm.2020.8982] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Elderly people perform more slowly movements of everyday life as rising from a chair, walking, and climbing stairs. This is in the first place due to the loss of muscle contractile force which is even more pronounced than the loss of muscle mass. In addition, a secondary, but not negligible, component is the rigidity or increased stiffness which requires greater effort to produce the same movement and limits the range of motion of the joints. In this short review, we discuss the possible determinants of the limitations of joint mobility in healthy elderly, starting with the age-dependent alterations of the articular structure and focusing on the increased stiffness of the skeletal muscles. Thereafter, the possible mechanisms of the increased stiffness of the muscle-tendon complex are considered, among them changes in the muscle fibers, alterations of the connective components (extracellular matrix or ECM, aponeurosis, fascia and tendon) and remodeling of the neural pattern of muscle activation with increased of antagonist co-activation.
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12
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Marcucci L, Reggiani C. Increase of resting muscle stiffness, a less considered component of age-related skeletal muscle impairment. Eur J Transl Myol 2020; 30:8982. [PMID: 32782762 PMCID: PMC7385684 DOI: 10.4081/ejtm.2019.8982] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Elderly people perform more slowly movements of everyday life as rising from a chair, walking, and climbing stairs. This is in the first place due to the loss of muscle contractile force which is even more pronounced than the loss of muscle mass. In addition, a secondary, but not negligible, component is the rigidity or increased stiffness which requires greater effort to produce the same movement and limits the range of motion of the joints. In this short review, we discuss the possible determinants of the limitations of joint mobility in healthy elderly, starting with the age-dependent alterations of the articular structure and focusing on the increased stiffness of the skeletal muscles. Thereafter, the possible mechanisms of the increased stiffness of the muscle-tendon complex are considered, among them changes in the muscle fibers, alterations of the connective tissue components, i.e., extracellular matrix (ECM), aponeurosis, tendon and fascia, and remodeling of the neural pattern of muscle activation that increases antagonist co-activation.
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Affiliation(s)
- Lorenzo Marcucci
- Department of Biomedical Sciences, Padova University, Padova, Italy.,Center for Mechanics of Biological Materials, Padova University, Padova, Italy.,Center for Biosystems Dynamics Research, RIKEN, Suita, Osaka, 565-0874, Japan
| | - Carlo Reggiani
- Department of Biomedical Sciences, Padova University, Padova, Italy.,Center for Mechanics of Biological Materials, Padova University, Padova, Italy.,Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
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13
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Alterations of Extracellular Matrix Mechanical Properties Contribute to Age-Related Functional Impairment of Human Skeletal Muscles. Int J Mol Sci 2020; 21:ijms21113992. [PMID: 32498422 PMCID: PMC7312402 DOI: 10.3390/ijms21113992] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/29/2020] [Accepted: 05/29/2020] [Indexed: 12/30/2022] Open
Abstract
Aging of human skeletal muscles is associated with increased passive stiffness, but it is still debated whether muscle fibers or extracellular matrix (ECM) are the determinants of such change. To answer this question, we compared the passive stress generated by elongation of fibers alone and arranged in small bundles in young healthy (Y: 21 years) and elderly (E: 67 years) subjects. The physiological range of sarcomere length (SL) 2.5-3.3 μm was explored. The area of ECM between muscle fibers was determined on transversal sections with picrosirius red, a staining specific for collagen fibers. The passive tension of fiber bundles was significantly higher in E compared to Y at all SL. However, the resistance to elongation of fibers alone was not different between the two groups, while the ECM contribution was significantly increased in E compared to Y. The proportion of muscle area occupied by ECM increased from 3.3% in Y to 8.2% in E. When the contribution of ECM to bundle tension was normalized to the fraction of area occupied by ECM, the difference disappeared. We conclude that, in human skeletal muscles, the age-related reduced compliance is due to an increased stiffness of ECM, mainly caused by collagen accumulation.
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Sinha U, Malis V, Csapo R, Narici M, Sinha S. Magnetic resonance imaging based muscle strain rate mapping during eccentric contraction to study effects of unloading induced by unilateral limb suspension. Eur J Transl Myol 2020; 30:8935. [PMID: 32499902 PMCID: PMC7254429 DOI: 10.4081/ejtm.2019.8935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 11/23/2022] Open
Abstract
Age- and disuse- related loss of muscle force is disproportionately larger than the loss of muscle mass. Earlier studies reported that comparing concentric and eccentric contractions, there is a significant age-related decrease in force only in concentric contractions. Magnetic Resonance Imaging enables mapping of muscle deformation and has been used to study isometric but not eccentric contractions. We report MRI based strain rate mapping of the medial gastrocnemius in subjects pre- and post-unloading induced by Unilateral Limb Suspension. In contrast to isometric contraction, no difference in strain rate indices were observed post-unloading, in conformance with preserved force during eccentric contractions.
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Affiliation(s)
- Usha Sinha
- Department of Physics, San Diego State University, San Diego, CA, USA
| | - Vadim Malis
- Department of Physics, University of California San Diego, San Diego, CA, USA
| | - Robert Csapo
- Private University for Health Sciences, Medical Informatics and Technology, ISAG, Research Unit for Orthopedic Sports Medicine and Injury Prevention, Hall, Austria
| | - Marco Narici
- Institute of Physiology, Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Shantanu Sinha
- Department of Radiology, University of California San Diego, San Diego, CA, USA
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