1
|
Yin X, Vesvoranan O, Andreopoulos F, Dauer EA, Gu W, Huang CYC. Analysis of Extracellular ATP Distribution in the Intervertebral Disc. Ann Biomed Eng 2024; 52:542-555. [PMID: 37934317 DOI: 10.1007/s10439-023-03398-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 10/25/2023] [Indexed: 11/08/2023]
Abstract
Progressive loss of proteoglycans (PGs) is the major biochemical change during intervertebral disc (IVD) degeneration. Adenosine triphosphate (ATP) as the primary energy source is not only critical for cell survival but also serves as a building block in PG synthesis. Extracellular ATP can mediate a variety of physiological functions and was shown to promote extracellular matrix (ECM) production in the IVD. Therefore, the objective of this study was to develop a 3D finite element model to predict extracellular ATP distribution in the IVD and evaluate the impact of degeneration on extracellular ATP distribution. A novel 3D finite element model of the IVD was developed by incorporating experimental measurements of ATP metabolism and ATP-PG binding kinetics into the mechano-electrochemical mixture theory. The new model was validated by experimental data of porcine IVD, and then used to analyze the extracellular distribution of ATP in human IVDs. Extracellular ATP was shown to bind specifically with PGs in IVD ECM. It was found that annulus fibrosus cells hydrolyze ATP faster than that of nucleus pulposus (NP) cells whereas NP cells exhibited a higher ATP release. The distribution of extracellular ATP in a porcine model was consistent with experimental data in our previous study. The predictions from a human IVD model showed a high accumulation of extracellular ATP in the NP region, whereas the extracellular ATP level was reduced with tissue degeneration. This study provides an understanding of extracellular ATP metabolism and its potential biological influences on the IVD via purinergic signaling.
Collapse
Affiliation(s)
- Xue Yin
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Oraya Vesvoranan
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Fotios Andreopoulos
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Edward A Dauer
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Weiyong Gu
- Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL, USA
| | - C-Y Charles Huang
- Department of Biomedical Engineering, College of Engineering, University of Miami, P.O. Box 248294, Coral Gables, FL, 33124-0621, USA.
| |
Collapse
|
2
|
McDonnell EE, Buckley CT. Consolidating and re-evaluating the human disc nutrient microenvironment. JOR Spine 2022; 5:e1192. [PMID: 35386756 PMCID: PMC8966889 DOI: 10.1002/jsp2.1192] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 12/14/2021] [Accepted: 01/07/2022] [Indexed: 12/19/2022] Open
Abstract
Background Despite exciting advances in regenerative medicine, cell‐based strategies for treating degenerative disc disease remain in their infancy. To maximize the potential for successful clinical translation, a more thorough understanding of the in vivo microenvironment is needed to better determine and predict how cell therapies will respond when administered in vivo. Aims This work aims to reflect on the in vivo nutrient microenvironment of the degenerating IVD through consolidating what has already been measured together with investigative in silico models. Materials and Methods This work uses in silico modeling, underpinned by more recent experimentally determined parameters of degeneration and nutrient transport from the literature, to re‐evaluate the current knowledge in terms of grade‐specific stages of degeneration. Results Through modeling only the metabolically active cell population, this work predicts slightly higher glucose concentrations compared to previous in silico models, while the predicted results show good agreement with previous intradiscal pH and oxygen measurements. Increasing calcification with degeneration limits nutrient transport into the IVD and initiates a build‐up of acidity; however, its effect is compensated somewhat by a reduction in diffusional distance due to decreasing disc height. Discussion This work advances in silico modeling through a strong foundation of experimentally determined grade‐specific input parameters. Taken together, pre‐existing measurements and predicted results suggest that metabolite concentrations may not be as critically low as commonly believed, with calcification not appearing to have a detrimental effect at stages of degeneration when cell therapies are an appropriate intervention. Conclusion Overall, our initiative is to provoke greater deliberation and consideration of the nutrient microenvironment when performing in vitro cell culture and cell therapy development. This work highlights urgency for robust experimental glucose measurements in healthy and degenerating IVDs, not only to validate in silico models but to significantly advance the field in fully elucidating the nutrient microenvironment and refining in vitro techniques to accelerate clinical translation.
Collapse
Affiliation(s)
- Emily E McDonnell
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin The University of Dublin Dublin Ireland.,Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin The University of Dublin Dublin Ireland
| | - Conor T Buckley
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin The University of Dublin Dublin Ireland.,Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin The University of Dublin Dublin Ireland.,Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland & Trinity College Dublin The University of Dublin Dublin Ireland.,Tissue Engineering Research Group, Department of Anatomy and Regenerative Medicine Royal College of Surgeons in Ireland Dublin Ireland
| |
Collapse
|
3
|
Zheng K, Du D. Recent advances of hydrogel-based biomaterials for intervertebral disc tissue treatment: A literature review. J Tissue Eng Regen Med 2021; 15:299-321. [PMID: 33660950 DOI: 10.1002/term.3172] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 12/14/2022]
Abstract
Low back pain is an increasingly prevalent symptom mainly associated with intervertebral disc (IVD) degeneration. It is highly correlated with aging, as the nucleus pulposus (NP) dehydrates and annulus fibrosus fissure formatting, which finally results in the IVD herniation and related clinical symptoms. Hydrogels have been drawing increasing attention as the ideal candidates for IVD degeneration because of their unique properties such as biocompatibility, highly tunable mechanical properties, and especially the water absorption and retention ability resembling the normal NP tissue. Numerous innovative hydrogel polymers have been generated in the most recent years. This review article will first briefly describe the anatomy and pathophysiology of IVDs and current therapies with their limitations. Following that, the article introduces the hydrogel materials in the classification of their origins. Next, it reviews the recent hydrogel polymers explored for IVD regeneration and analyses what efforts have been made to overcome the existing limitations. Finally, the challenges and prospects of hydrogel-based treatments for IVD tissue are also discussed. We believe that these novel hydrogel-based strategies may shed light on new possibilities in IVD degeneration disease.
Collapse
Affiliation(s)
- Kaiwen Zheng
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Dajiang Du
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| |
Collapse
|
4
|
Baumgartner L, Wuertz-Kozak K, Le Maitre CL, Wignall F, Richardson SM, Hoyland J, Ruiz Wills C, González Ballester MA, Neidlin M, Alexopoulos LG, Noailly J. Multiscale Regulation of the Intervertebral Disc: Achievements in Experimental, In Silico, and Regenerative Research. Int J Mol Sci 2021; 22:E703. [PMID: 33445782 PMCID: PMC7828304 DOI: 10.3390/ijms22020703] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/17/2022] Open
Abstract
Intervertebral disc (IVD) degeneration is a major risk factor of low back pain. It is defined by a progressive loss of the IVD structure and functionality, leading to severe impairments with restricted treatment options due to the highly demanding mechanical exposure of the IVD. Degenerative changes in the IVD usually increase with age but at an accelerated rate in some individuals. To understand the initiation and progression of this disease, it is crucial to identify key top-down and bottom-up regulations' processes, across the cell, tissue, and organ levels, in health and disease. Owing to unremitting investigation of experimental research, the comprehension of detailed cell signaling pathways and their effect on matrix turnover significantly rose. Likewise, in silico research substantially contributed to a holistic understanding of spatiotemporal effects and complex, multifactorial interactions within the IVD. Together with important achievements in the research of biomaterials, manifold promising approaches for regenerative treatment options were presented over the last years. This review provides an integrative analysis of the current knowledge about (1) the multiscale function and regulation of the IVD in health and disease, (2) the possible regenerative strategies, and (3) the in silico models that shall eventually support the development of advanced therapies.
Collapse
Affiliation(s)
- Laura Baumgartner
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
| | - Karin Wuertz-Kozak
- Department of Biomedical Engineering, Rochester Institute of Technology (RIT), Rochester, NY 14623, USA;
- Schön Clinic Munich Harlaching, Spine Center, Academic Teaching Hospital and Spine Research Institute of the Paracelsus Medical University Salzburg (Austria), 81547 Munich, Germany
| | - Christine L. Le Maitre
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK;
| | - Francis Wignall
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Stephen M. Richardson
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Judith Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Sciences Centre, Oxford Road, Manchester M13 9PT, UK; (F.W.); (S.M.R.); (J.H.)
| | - Carlos Ruiz Wills
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
| | - Miguel A. González Ballester
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
- Catalan Institution for Research and Advanced Studies (ICREA), Pg. Lluis Companys 23, 08010 Barcelona, Spain
| | - Michael Neidlin
- Department of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece; (M.N.); (L.G.A.)
| | - Leonidas G. Alexopoulos
- Department of Mechanical Engineering, National Technical University of Athens, 15780 Athens, Greece; (M.N.); (L.G.A.)
| | - Jérôme Noailly
- BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain; (L.B.); (C.R.W.); (M.A.G.B.)
| |
Collapse
|
5
|
Yin X, Motorwala A, Vesvoranan O, Levene HB, Gu W, Huang CY. Effects of Glucose Deprivation on ATP and Proteoglycan Production of Intervertebral Disc Cells under Hypoxia. Sci Rep 2020; 10:8899. [PMID: 32483367 PMCID: PMC7264337 DOI: 10.1038/s41598-020-65691-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/05/2020] [Indexed: 12/25/2022] Open
Abstract
As the most common cause of low back pain, the cascade of intervertebral disc (IVD) degeneration is initiated by the disappearance of notochordal cells and progressive loss of proteoglycan (PG). Limited nutrient supply in the avascular disc environment restricts the production of ATP which is an essential energy source for cell survival and function such as PG biosynthesis. The objective of this study was to examine ATP level and PG production of porcine IVD cells under prolonged exposure to hypoxia with physiological glucose concentrations. The results showed notochordal NP and AF cells responded differently to changes of oxygen and glucose. Metabolic activities (including PG production) of IVD cells are restricted under the in-vivo nutrient conditions while NP notochordal cells are likely to be more vulnerable to reduced nutrition supply. Moreover, provision of energy, together or not with genetic regulation, may govern PG production in the IVD under restricted nutrient supply. Therefore, maintaining essential levels of nutrients may reduce the loss of notochordal cells and PG in the IVD. This study provides a new insight into the metabolism of IVD cells under nutrient deprivation and the information for developing treatment strategies for disc degeneration.
Collapse
Affiliation(s)
- Xue Yin
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Aarif Motorwala
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Oraya Vesvoranan
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
| | - Howard B Levene
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Weiyong Gu
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.,Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL, USA
| | - Chun-Yuh Huang
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
| |
Collapse
|
6
|
Tissue Engineering Strategies for Intervertebral Disc Treatment Using Functional Polymers. Polymers (Basel) 2019; 11:polym11050872. [PMID: 31086085 PMCID: PMC6572548 DOI: 10.3390/polym11050872] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 02/07/2023] Open
Abstract
Intervertebral disc (IVD) is the fibrocartilage between the vertebrae, allowing the spine to move steadily by bearing multidirectional complex loads. Aging or injury usually causes degeneration of IVD, which is one of the main reasons for low back pain prevalent worldwide and reduced quality of life. While various treatment strategies for degenerative IVD have been studied using in vitro studies, animal experiments, and clinical trials, there are unsolved limitations for endogenous regeneration of degenerative IVD. In this respect, several tissue engineering strategies that are based on the cell and scaffolds have been extensively researched with positive outcomes for regeneration of IVD tissues. Scaffolds made of functional polymers and their diverse forms mimicking the macro- and micro-structure of native IVD enhance the biological and mechanical properties of the scaffolds for IVD regeneration. In this review, we discuss diverse morphological and functional polymers and tissue engineering strategies for endogenous regeneration of degenerative IVD. Tissue engineering strategies using functional polymers are promising therapeutics for fundamental and endogenous regeneration of degenerative IVD.
Collapse
|