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Höflsauer S, Bonnaire FC, Bamberger CE, Danalache M, Feierabend M, Hofmann UK. Changes in stiffness of the extracellular and pericellular matrix in the anulus fibrosus of lumbar intervertebral discs over the course of degeneration. Front Bioeng Biotechnol 2022; 10:1006615. [PMID: 36619385 PMCID: PMC9816436 DOI: 10.3389/fbioe.2022.1006615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/08/2022] [Indexed: 12/24/2022] Open
Abstract
Analogous to articular cartilage, changes in spatial chondrocyte organisation have been proposed to be a strong indicator for local tissue degeneration in the intervertebral disc (IVD). While a progressive structural and functional degradation of the extracellular (ECM) and pericellular (PCM) matrix occurs in osteoarthritic cartilage, these processes have not yet been biomechanically elucidated in the IVD. We aimed to evaluate the local stiffness of the ECM and PCM in the anulus fibrosus of the IVD on the basis of local chondrocyte spatial organisation. Using atomic force microscopy, we measured the Young's modulus of the local ECM and PCM in human and bovine disc samples using the spatial chondrocyte patterns as an image-based biomarker. By measuring tissue from 31 patients and six bovine samples, we found a significant difference in the elastic moduli (E) of the PCM in clusters when compared to the healthy patterns single cells (p = 0.029), pairs (p = 0.016), and string-formations (p = 0.010). The ECM/PCM ratio ranged from 0.62-0.89. Interestingly, in the bovine IVD, the ECM/PCM ratio of the E significantly varied (p = 0.002) depending on the tissue origin. Overall the reduced E in clusters demonstrates that cluster formation is not only a morphological phenomenon describing disc degeneration, but it marks a compromised biomechanical functioning. Immunohistochemical analyses indicate that collagen type III degradation might be involved. This study is the first to describe and quantify the differences in the E of the ECM in relation to the PCM in the anulus fibrosus of the IVD by means of atomic force microscopy on the basis of spatial chondrocyte organisation.
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Affiliation(s)
- Sebastian Höflsauer
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany,Medical Faculty of the University of Tübingen, Tübingen, Germany
| | - Florian Christof Bonnaire
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany,Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany
| | - Charlotte Emma Bamberger
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany,Medical Faculty of the University of Tübingen, Tübingen, Germany
| | - Marina Danalache
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany,Medical Faculty of the University of Tübingen, Tübingen, Germany
| | - Martina Feierabend
- Institute for Bioinformatics and Medical Informatics, Faculty of Science of the University of Tübingen, Tübingen, Germany,*Correspondence: Martina Feierabend,
| | - Ulf Krister Hofmann
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Tübingen, Germany,Department of Orthopaedic Trauma and Reconstructive Surgery, RWTH Aachen University Hospital, Aachen, Germany
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Cykowska A, Danalache M, Bonnaire FC, Feierabend M, Hofmann UK. Detecting early osteoarthritis through changes in biomechanical properties - A review of recent advances in indentation technologies in a clinical arthroscopic setup. J Biomech 2022; 132:110955. [PMID: 35042088 DOI: 10.1016/j.jbiomech.2022.110955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/29/2021] [Accepted: 01/07/2022] [Indexed: 11/19/2022]
Abstract
Osteoarthritis (OA) is a degenerative joint disease currently affecting half of all women and one-third of all men aged over 65 and it is predicted to even increase in the next decades. In the variety of causes leading to OA, the first common denominator are changes in the extracellular matrix of the cartilage. In later stages, OA affects the whole joint spreading to higher levels of tissue architecture causing irreversible functional and structural damage. To date, the diagnosis of OA is only formulated in the late stages of the disease. This is also, where most present therapies apply. Since a precise diagnosis is a prerequisite for targeted therapy, tools to diagnose early OA, monitor its progression, and accurately stage the disease are wanted. This review article focuses on recent advances in indentation technologies to diagnose early OA through describing biomechanical cartilage characteristics. We provide an overview of microindentation instruments, indentation-type Atomic Force Microscopy, ultrasound, and water-jet ultrasound indentation, Optical Coherence Tomography-based air-jet indentation, as well as fiber Bragg grating.
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Affiliation(s)
- Anna Cykowska
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, D-72072 Tübingen, Germany.
| | - Marina Danalache
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, D-72072 Tübingen, Germany.
| | - Florian Christof Bonnaire
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, D-72072 Tübingen, Germany; Department of Orthopaedic Surgery, University Hospital of Tübingen, D-72076 Tübingen, Germany.
| | - Martina Feierabend
- Department of Computational Systems Biology, Faculty of Science of the University of Tübingen, D-72076 Tübingen, Germany.
| | - Ulf Krister Hofmann
- Laboratory of Cell Biology, Department of Orthopaedic Surgery, University Hospital of Tübingen, D-72072 Tübingen, Germany; Department of Orthopaedic, Trauma, and Reconstructive Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074 Aachen, Germany.
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Bonnaire FC, Danalache M, Sigwart VA, Breuer W, Rolauffs B, Hofmann UK. The intervertebral disc from embryonic development to disc degeneration: insights into spatial cellular organization. Spine J 2021; 21:1387-1398. [PMID: 33872805 DOI: 10.1016/j.spinee.2021.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/10/2021] [Accepted: 04/13/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Low back pain is commonly attributed to intervertebral disc (IVD) degeneration. IVD resembles articular cartilage in its biochemical and cellular composition in many ways. For articular cartilage, degeneration stage-specific characteristic spatial chondrocyte patterns have recently been described. PURPOSE This study addresses how spatial chondrocyte organization in the IVD changes from early embryonic development to end stage degeneration. STUDY DESIGN Ex vivo immunohistochemical analysis. METHODS We immunohistochemically investigated bovine IVD-tissue (n=72) from early embryonic development to early disc degeneration and human adult IVD-tissue (n=25) operated for trauma or degeneration for cellular density and chondrocyte spatial organization. IVD samples were sectioned along the main collagen fiber orientation. Nuclei were stained with DAPI and their number and spatial patterns were analyzed in an area of 250,000 µm² for each tissue category. RESULTS The initially very high cellular density in the early embryonic bovine disc (11,431 cells/mm²) steadily decreases during gestation, growth and maturation to about 71 cell/mm² in the fully grown cattle. Interestingly, in human degenerative discs, a new increase in this figure could be noted (184 cells/mm). The IVD chondrocytes appear to be predominantly present as single cells. Especially in the time after birth, string-formations represent up to 32% of all cells in the anulus fibrosus, although single cells are the predominant spatial pattern (>50%) over the entire time. With increasing degeneration, the relative proportion of single cells in human IVDs continuously decreases (12%). At the same time, the share of cells organized in clusters increases (70%). CONCLUSION Similar to articular cartilage, spatial chondrocyte organization appears to be a strong indicator for local tissue degeneration in the IVD. CLINICAL SIGNIFICANCE In the future these findings may be important for the detection and therapy of IVD degeneration in early stages.
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Affiliation(s)
- Florian Christof Bonnaire
- Laboratory of Cell Biology, Department of Orthopedic Surgery University Hospital of Tübingen, Waldhörnlestraße 22, 72072 Tübingen, Germany; Department of Orthopedic Surgery University Hospital of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany.
| | - Marina Danalache
- Laboratory of Cell Biology, Department of Orthopedic Surgery University Hospital of Tübingen, Waldhörnlestraße 22, 72072 Tübingen, Germany
| | - Viktor Amadeus Sigwart
- Laboratory of Cell Biology, Department of Orthopedic Surgery University Hospital of Tübingen, Waldhörnlestraße 22, 72072 Tübingen, Germany; Medical Faculty of the University of Tübingen, Geissweg 5/1, 72076 Tübingen, Germany
| | - Wolfram Breuer
- Bavarian Health and Food Authority, Veterinärstraße 2, 85764 Oberschleißheim, Germany
| | - Bernd Rolauffs
- Research Center for Tissue Replacement, Regeneration & Neogenesis, Department of Orthopedics and Trauma Surgery, Faculty of Medicine, Medical Center - Albert-Ludwigs-University of Freiburg, Hugstetter Straße 55, 79106 Freiburg im Breisgau, Germany
| | - Ulf Krister Hofmann
- Laboratory of Cell Biology, Department of Orthopedic Surgery University Hospital of Tübingen, Waldhörnlestraße 22, 72072 Tübingen, Germany; Department of Orthopedic Surgery University Hospital of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany
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Bonnaire FC, Feierabend M, Wolfgart JM, Breuer W, Walter C, Hofmann UK, Danalache M. Optical Sectioning and Visualization of the Intervertebral Disc from Embryonic Development to Degeneration. J Vis Exp 2021. [PMID: 34309598 DOI: 10.3791/62594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Intervertebral disc (IVD) degeneration is a leading cause of low back pain and it entails a high degree of impairment for the affected individuals. To decode disc degeneration and to be able to develop regenerative approaches a thorough understanding of the cellular biology of the IVD is essential. One aspect of this biology that still remains unanswered is the question of how cells are spatially arranged in a physiological state and during degeneration. The biological properties of the IVD and its availability make this tissue difficult to analyze. The present study investigates spatial chondrocyte organization in the anulus fibrosus from early embryonic development to end-stage degeneration. An optical sectioning method (Apotome) is applied to perform high resolution staining analyses using bovine embryonic tissue as an animal model and human disc tissue obtained from patients undergoing spine surgery. From a very high chondrocyte density in the early embryonic bovine disc, the number of cells decreases during gestation, growth, and maturation. In human discs, an increase in cellular density accompanied the progression of tissue degeneration. As had already been demonstrated in articular cartilage, cluster formation represents a characteristic feature of advanced disc degeneration.
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Affiliation(s)
- Florian Christof Bonnaire
- Laboratory of Cell Biology, Department of Orthopedic Surgery, University Hospital of Tübingen; Department of Orthopedic Surgery, University Hospital of Tübingen
| | - Martina Feierabend
- Institute for Bioinformatics and Medical Informatics, Faculty of science of the University of Tübingen;
| | - Julius Michael Wolfgart
- Laboratory of Cell Biology, Department of Orthopedic Surgery, University Hospital of Tübingen; Medical faculty of the University of Tübingen
| | | | - Christian Walter
- Department of Orthopedic Surgery, University Hospital of Tübingen
| | - Ulf Krister Hofmann
- Laboratory of Cell Biology, Department of Orthopedic Surgery, University Hospital of Tübingen; Department of Orthopedic Surgery, University Hospital of Tübingen
| | - Marina Danalache
- Laboratory of Cell Biology, Department of Orthopedic Surgery, University Hospital of Tübingen
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Danalache M, Beutler KR, Rolauffs B, Wolfgart JM, Bonnaire FC, Fischer S, Greving I, Hofmann UK. Exploration of changes in spatial chondrocyte organisation in human osteoarthritic cartilage by means of 3D imaging. Sci Rep 2021; 11:9783. [PMID: 33963289 PMCID: PMC8105369 DOI: 10.1038/s41598-021-89582-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 04/28/2021] [Indexed: 12/11/2022] Open
Abstract
Using two-dimensional top-down view microscopy, researchers have recently described chondrocytes as being spatially arranged in distinct patterns such as strings, double strings, and small and large clusters. Because of the seeming association of these changes with tissue degeneration, they have been proposed as an image-based biomarker for early osteoarthritis (OA) staging. The aim of our study was to investigate the spatial arrangement of chondrocytes in human articular cartilage in a 3D fashion and to evaluate the 3D changes of these patterns in the context of local tissue destruction. Decalcified femoral condyle resections from the load-bearing area were analysed in 3D for their spatial chondrocyte organisation by means of fluorescence microscopy and synchrotron-radiation micro-computed tomography (SR-µCT). In intact cartilage chondrocyte strings can be found in the superficial, transitional and deep zones. The proposed pattern changes accompanying tissue destruction could be located not just along the surface but also through all layers of cartilage. Each spatial pattern was characterised by a different cellular density (the only exception being between single and double strings with p = 0.062), with cellular density significantly increasing alongside the increase in local tissue degeneration as defined by the chondrocyte patterns. We can thus corroborate that the proposed cellular spatial changes are a three-dimensional function of local tissue degeneration, underlining their relevance as an image-based biomarker for the early diagnosis and description of OA. Clinical trial registration number: Project number of the ethics committee of the University of Tübingen:171/2014BO2.
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Affiliation(s)
- Marina Danalache
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - Kevin Ralf Beutler
- Medical Faculty of the University of Tübingen, 72076, Tübingen, Germany. .,Department of Orthopaedic Surgery and Traumatology, Spital Thurgau AG, Spitalcampus 1, 8596, Münsterlingen, Switzerland.
| | - Bernd Rolauffs
- G.E.R.N. Tissue Replacement, Regeneration and Neogenesis, Department of Orthopedics and Trauma Surgery, Medical Center - Albert-Ludwigs-University of Freiburg, Faculty of Medicine, Albert-Ludwigs-University of Freiburg, 79108, Freiburg, Germany
| | | | - Florian Christof Bonnaire
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
| | - Stefan Fischer
- Department of Evolutionary Biology of Invertebrates, University of Tübingen, 72076, Tübingen, Germany.,Tübingen Structural Microscopy (TSM), Center for Applied Geoscience (ZAG), University of Tübingen, 72076, Tübingen, Germany
| | - Imke Greving
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
| | - Ulf Krister Hofmann
- Department of Orthopaedic Surgery, University Hospital of Tübingen, Hoppe-Seyler-Strasse 3, 72076, Tübingen, Germany
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