1
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Schurman CA, Kaya S, Dole N, Luna NMM, Castillo N, Potter R, Rose JP, Bons J, King CD, Burton JB, Schilling B, Melov S, Tang S, Schaible E, Alliston T. Aging impairs the osteocytic regulation of collagen integrity and bone quality. Bone Res 2024; 12:13. [PMID: 38409111 PMCID: PMC10897167 DOI: 10.1038/s41413-023-00303-7] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/31/2023] [Accepted: 11/13/2023] [Indexed: 02/28/2024] Open
Abstract
Poor bone quality is a major factor in skeletal fragility in elderly individuals. The molecular mechanisms that establish and maintain bone quality, independent of bone mass, are unknown but are thought to be primarily determined by osteocytes. We hypothesize that the age-related decline in bone quality results from the suppression of osteocyte perilacunar/canalicular remodeling (PLR), which maintains bone material properties. We examined bones from young and aged mice with osteocyte-intrinsic repression of TGFβ signaling (TβRIIocy-/-) that suppresses PLR. The control aged bone displayed decreased TGFβ signaling and PLR, but aging did not worsen the existing PLR suppression in male TβRIIocy-/- bone. This relationship impacted the behavior of collagen material at the nanoscale and tissue scale in macromechanical tests. The effects of age on bone mass, density, and mineral material behavior were independent of osteocytic TGFβ. We determined that the decline in bone quality with age arises from the loss of osteocyte function and the loss of TGFβ-dependent maintenance of collagen integrity.
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Affiliation(s)
- Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Serra Kaya
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Neha Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Nadja M Maldonado Luna
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
| | - Natalia Castillo
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA
| | - Ryan Potter
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Jacob P Rose
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Joanna Bons
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Jordan B Burton
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | | | - Simon Melov
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Simon Tang
- Washington University in St Louis, Department of Orthopedics, St. Louis, MO, 63130, USA
| | - Eric Schaible
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, 94143, USA.
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA.
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2
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Vetter SD, Schurman CA, Alliston T, Slabaugh GG, Verbruggen SW. Deep learning models to map osteocyte networks can successfully distinguish between young and aged bone. bioRxiv 2023:2023.12.20.572567. [PMID: 38187546 PMCID: PMC10769292 DOI: 10.1101/2023.12.20.572567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Osteocytes, the most abundant and mechanosensitive cells in bone tissue, play a pivotal role in bone homeostasis and mechano-responsiveness, orchestrating the intricate balance between bone formation and resorption under daily activity. Studying osteocyte connectivity and understanding their intricate arrangement within the lacunar canalicular network (LCN) is essential for unraveling bone physiology. This is particularly true as our bones age, which is associated with decreased integrity of the osteocyte network, disrupted mass transport, and lower sensitivity to the mechanical stimuli that allow the skeleton to adapt to changing demands. Much work has been carried out to investigate this relationship, often involving high resolution microscopy of discrete fragments of this network, alongside advanced computational modelling of individual cells. However, traditional methods of segmenting and measuring osteocyte connectomics are time-consuming and labour-intensive, often hindered by human subjectivity and limited throughput. In this study, we explore the application of deep learning and computer vision techniques to automate the segmentation and measurement of osteocyte connectomics, enabling more efficient and accurate analysis. We compare several state-of-the-art computer vision models (U-Nets and Vision Transformers) to successfully segment the LCN, finding that an Attention U-Net model can accurately segment and measure 81.8% of osteocytes and 42.1% of dendritic processes, when compared to manual labelling. While further development is required, we demonstrate that this degree of accuracy is already sufficient to distinguish between bones of young (2 month old) and aged (36 month old) mice, as well as capturing the degeneration induced by genetic modification of osteocytes. By harnessing the power of these advanced technologies, further developments can unravel the complexities of osteocyte networks in unprecedented detail, revolutionising our understanding of bone health and disease.
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Affiliation(s)
- Simon D. Vetter
- School of Electronic Engineering and Computer Science, Queen Mary University of London, UK
- Digital Environment Research Institute, Queen Mary University of London, UK
| | - Charles A. Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA 94143, USA
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA 94143, USA
| | - Gregory G. Slabaugh
- School of Electronic Engineering and Computer Science, Queen Mary University of London, UK
- Digital Environment Research Institute, Queen Mary University of London, UK
- Alan Turing Institute, British Library, 96 Euston Rd, London NW1 2DB, UK
| | - Stefaan W. Verbruggen
- Digital Environment Research Institute, Queen Mary University of London, UK
- Centre for Predictive in vitro Models, School of Engineering and Materials Science, Queen Mary University of London, UK
- INSIGNEO Institute for In Silico Medicine, University of Sheffield, UK
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Rose JP, Schurman CA, King CD, Bons J, Patel SK, Burton JB, O’Broin A, Alliston T, Schilling B. Deep coverage and quantification of the bone proteome provides enhanced opportunities for new discoveries in skeletal biology and disease. PLoS One 2023; 18:e0292268. [PMID: 37816044 PMCID: PMC10564166 DOI: 10.1371/journal.pone.0292268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Dysregulation of cell signaling in chondrocytes and in bone cells, such as osteocytes, osteoblasts, osteoclasts, and an elevated burden of senescent cells in cartilage and bone, are implicated in osteoarthritis (OA). Mass spectrometric analyses provides a crucial molecular tool-kit to understand complex signaling relationships in age-related diseases, such as OA. Here we introduce a novel mass spectrometric workflow to promote proteomic studies of bone. This workflow uses highly specialized steps, including extensive overnight demineralization, pulverization, and incubation for 72 h in 6 M guanidine hydrochloride and EDTA, followed by proteolytic digestion. Analysis on a high-resolution Orbitrap Eclipse and Orbitrap Exploris 480 mass spectrometer using Data-Independent Acquisition (DIA) provides deep coverage of the bone proteome, and preserves post-translational modifications, such as hydroxyproline. A spectral library-free quantification strategy, directDIA, identified and quantified over 2,000 protein groups (with ≥ 2 unique peptides) from calcium-rich bone matrices. Key components identified were proteins of the extracellular matrix (ECM), bone-specific proteins (e.g., secreted protein acidic and cysteine rich, SPARC, and bone sialoprotein 2, IBSP), and signaling proteins (e.g., transforming growth factor beta-2, TGFB2), and lysyl oxidase homolog 2 (LOXL2), an important protein in collagen crosslinking. Post-translational modifications (PTMs) were identified without the need for specific enrichment. This includes collagen hydroxyproline modifications, chemical modifications for collagen self-assembly and network formation. Multiple senescence factors were identified, such as complement component 3 (C3) protein of the complement system and many matrix metalloproteinases, that might be monitored during age-related bone disease progression. Our innovative workflow yields in-depth protein coverage and quantification strategies to discover underlying biological mechanisms of bone aging and to provide tools to monitor therapeutic interventions. These novel tools to monitor the bone proteome open novel horizons to investigate bone-specific diseases, many of which are age-related.
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Affiliation(s)
- Jacob P. Rose
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | | | - Christina D. King
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | - Joanna Bons
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | - Sandip K. Patel
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | - Jordan B. Burton
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | - Amy O’Broin
- Buck Institute for Research on Aging, Novato, CA, United States of America
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, Unted States of America
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, United States of America
| | - Birgit Schilling
- Buck Institute for Research on Aging, Novato, CA, United States of America
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Kaya S, Bailey KN, Schurman CA, Evans DS, Alliston T. Bone-cartilage crosstalk informed by aging mouse bone transcriptomics and human osteoarthritis genome-wide association studies. Bone Rep 2023; 18:101647. [PMID: 36636109 PMCID: PMC9830153 DOI: 10.1016/j.bonr.2022.101647] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/28/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022] Open
Abstract
Subchondral bone participates in crosstalk with articular cartilage to maintain joint homeostasis, and disruption of either tissue results in overall joint degeneration. Among the subchondral bone changes observed in osteoarthritis (OA), subchondral bone plate (SBP) thickening has a time-dependent relationship with cartilage degeneration and has recently been shown to be regulated by osteocytes. Here, we evaluate the effect of age on SBP thickness and cartilage degeneration in aging mice. We find that SBP thickness significantly increases by 18-months of age, corresponding temporally with increased cartilage degeneration. To identify factors in subchondral bone that may participate in bone cartilage crosstalk or OA, we leveraged mouse transcriptomic data from one joint tissue compartment - osteocyte-enriched bone - to search for enrichment with human OA in UK Biobank and Arthritis Research UK Osteoarthritis Genetics (arcOGEN) GWAS using the mouse2human (M2H, www.mouse2human.org) strategy. Genes differentially expressed in aging mouse bone are significantly enriched for human OA, showing joint site-specific (knee vs. hip) relationships, exhibit temporal associations with age, and unique gene clusters are implicated in each type of OA. Application of M2H identifies genes with known and unknown functions in osteocytes and OA development that are clinically associated with human OA. Altogether, this work prioritizes genes with a potential role in bone/cartilage crosstalk for further mechanistic study based on their association with human OA in GWAS.
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Affiliation(s)
- Serra Kaya
- Department of Orthopaedic Surgery, University of California San Francisco, CA, United States of America
| | - Karsyn N. Bailey
- Department of Orthopaedic Surgery, University of California San Francisco, CA, United States of America
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States of America
| | - Charles A. Schurman
- Department of Orthopaedic Surgery, University of California San Francisco, CA, United States of America
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States of America
| | - Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, CA, United States of America
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California San Francisco, CA, United States of America
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States of America
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Schurman CA, Burton JB, Rose J, Ellerby LM, Alliston T, Schilling B. Molecular and Cellular Crosstalk between Bone and Brain: Accessing Bidirectional Neural and Musculoskeletal Signaling during Aging and Disease. J Bone Metab 2023; 30:1-29. [PMID: 36950837 PMCID: PMC10036181 DOI: 10.11005/jbm.2023.30.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 03/24/2023] Open
Abstract
Molecular omics technologies, including proteomics, have enabled the elucidation of key signaling pathways that mediate bidirectional communication between the brain and bone tissues. Here we provide a brief summary of the clinical and molecular evidence of the need to study the bone-brain axis of cross-tissue cellular communication. Clear clinical and molecular evidence suggests biological interactions and similarities between bone and brain cells. Here we review the current mass spectrometric techniques for studying brain and bone diseases with an emphasis on neurodegenerative diseases and osteoarthritis/osteoporosis, respectively. Further study of the bone-brain axis on a molecular level and evaluation of the role of proteins, neuropeptides, osteokines, and hormones in molecular pathways linked to bone and brain diseases is critically needed. The use of mass spectrometry and other omics technologies to analyze these cross-tissue signaling events and interactions will help us better understand disease progression and comorbidities and potentially identify new pathways and targets for therapeutic interventions. Proteomic measurements are particularly favorable for investigating the role of signaling and secreted and circulating analytes and identifying molecular and metabolic pathways implicated in age-related diseases.
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Affiliation(s)
| | | | - Jacob Rose
- Buck Institute for Research on Aging, Novato, CA,
USA
| | | | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California San Francisco, San Francisco, CA,
USA
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6
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Kaya S, Schurman CA, Dole NS, Evans DS, Alliston T. Prioritization of Genes Relevant to Bone Fragility Through the Unbiased Integration of Aging Mouse Bone Transcriptomics and Human GWAS Analyses. J Bone Miner Res 2022; 37:804-817. [PMID: 35094432 PMCID: PMC9018503 DOI: 10.1002/jbmr.4516] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 12/20/2021] [Accepted: 01/17/2022] [Indexed: 11/10/2022]
Abstract
Identifying new genetic determinants of bone mineral density (BMD) and fracture promises to yield improved diagnostics and therapies for bone fragility. However, prioritizing candidate genes from genome-wide screens can be challenging. To overcome this challenge, we prioritized mouse genes that are differentially expressed in aging mouse bone based on whether their human homolog is associated with human BMD and/or fracture. Unbiased RNA-seq analysis of young and old male C57BL/6 mouse cortical bone identified 1499, 1685, and 5525 differentially expressed genes (DEGs) in 1, 2, and 2.5-year-old bone, relative to 2-month-old bone, respectively. Gene-based scores for heel ultrasound bone mineral density (eBMD) and fracture were estimated using published genome-wide association studies (GWAS) results of these traits in the UK Biobank. Enrichment analysis showed that mouse bone DEG sets for all three age groups, relative to young bone, are significantly enriched for eBMD, but only the oldest two DEG sets are enriched for fracture. Using gene-based scores, this approach prioritizes among thousands of DEGs by a factor of 5- to 100-fold, yielding 10 and 21 genes significantly associated with fracture in the two oldest groups of mouse DEGs. Though these genes were not the most differentially expressed, they included Sost, Lrp5, and others with well-established functions in bone. Several others have, as yet, unknown roles in the skeleton. Therefore, this study accelerates identification of new genetic determinants of bone fragility by prioritizing a clinically relevant and experimentally tractable number of candidate genes for functional analysis. Finally, we provide a website (www.mouse2human.org) to enable other researchers to easily apply our strategy. © 2022 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Serra Kaya
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
| | - Charles A. Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA
| | - Neha S. Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
| | - Daniel S. Evans
- California Pacific Medical Center Research Institute, San Francisco, CA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA
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7
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Monteiro DA, Dole NS, Campos JL, Kaya S, Schurman CA, Belair CD, Alliston T. Fluid shear stress generates a unique signaling response by activating multiple TGFβ family type I receptors in osteocytes. FASEB J 2021; 35:e21263. [PMID: 33570811 PMCID: PMC7888383 DOI: 10.1096/fj.202001998r] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/11/2020] [Accepted: 11/25/2020] [Indexed: 12/18/2022]
Abstract
Bone is a dynamic tissue that constantly adapts to changing mechanical demands. The transforming growth factor beta (TGFβ) signaling pathway plays several important roles in maintaining skeletal homeostasis by both coupling the bone‐forming and bone‐resorbing activities of osteoblasts and osteoclasts and by playing a causal role in the anabolic response of bone to applied loads. However, the extent to which the TGFβ signaling pathway in osteocytes is directly regulated by fluid shear stress (FSS) is unknown, despite work suggesting that fluid flow along canaliculi is a dominant physical cue sensed by osteocytes following bone compression. To investigate the effects of FSS on TGFβ signaling in osteocytes, we stimulated osteocytic OCY454 cells cultured within a microfluidic platform with FSS. We find that FSS rapidly upregulates Smad2/3 phosphorylation and TGFβ target gene expression, even in the absence of added TGFβ. Indeed, relative to treatment with TGFβ, FSS induced a larger increase in levels of pSmad2/3 and Serpine1 that persisted even in the presence of a TGFβ receptor type I inhibitor. Our results show that FSS stimulation rapidly induces phosphorylation of multiple TGFβ family R‐Smads by stimulating multimerization and concurrently activating several TGFβ and BMP type I receptors, in a manner that requires the activity of the corresponding ligand. While the individual roles of the TGFβ and BMP signaling pathways in bone mechanotransduction remain unclear, these results implicate that FSS activates both pathways to generate a downstream response that differs from that achieved by either ligand alone.
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Affiliation(s)
- David A Monteiro
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA
| | - Neha S Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - J Luke Campos
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Serra Kaya
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA
| | - Cassandra D Belair
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA.,Department of Urology, University of California, San Francisco, CA, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA
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8
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Schurman CA, Verbruggen SW, Alliston T. Disrupted osteocyte connectivity and pericellular fluid flow in bone with aging and defective TGF-β signaling. Proc Natl Acad Sci U S A 2021; 118:e2023999118. [PMID: 34161267 PMCID: PMC8237574 DOI: 10.1073/pnas.2023999118] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Skeletal fragility in the elderly does not simply result from a loss of bone mass. However, the mechanisms underlying the concurrent decline in bone mass, quality, and mechanosensitivity with age remain unclear. The important role of osteocytes in these processes and the age-related degeneration of the intricate lacunocanalicular network (LCN) in which osteocytes reside point to a primary role for osteocytes in bone aging. Since LCN complexity severely limits experimental dissection of these mechanisms in vivo, we used two in silico approaches to test the hypothesis that LCN degeneration, due to aging or an osteocyte-intrinsic defect in transforming growth factor beta (TGF-β) signaling (TβRIIocy-/-), is sufficient to compromise essential osteocyte responsibilities of mass transport and exposure to mechanical stimuli. Using reconstructed confocal images of bone with fluorescently labeled osteocytes, we found that osteocytes from aged and TβRIIocy-/- mice had 33 to 45% fewer, and more tortuous, canaliculi. Connectomic network analysis revealed that diminished canalicular density is sufficient to impair diffusion even with intact osteocyte numbers and overall LCN architecture. Computational fluid dynamics predicts that the corresponding drop in shear stress experienced by aged or TβRIIocy-/- osteocytes is highly sensitive to canalicular surface area but not tortuosity. Simulated expansion of the osteocyte pericellular space to mimic osteocyte perilacunar/canalicular remodeling restored predicted shear stress for aged osteocytes to young levels. Overall, these models show how loss of LCN volume through LCN pruning may lead to impaired fluid dynamics and osteocyte exposure to mechanostimulation. Furthermore, osteocytes emerge as targets of age-related therapeutic efforts to restore bone health and function.
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Affiliation(s)
- Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA 94143
| | - Stefaan W Verbruggen
- Institute of Bioengineering, School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom, E1 4NS
- Department of Mechanical Engineering, University of Sheffield, Sheffield, United Kingdom, S1 3JD
- The Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom, S1 3JD
- Department of Biomedical Engineering, Columbia University in the City of New York, New York, NY 10027
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA 94143;
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA 94143
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9
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Dole NS, Yee CS, Schurman CA, Dallas SL, Alliston T. Assessment of Osteocytes: Techniques for Studying Morphological and Molecular Changes Associated with Perilacunar/Canalicular Remodeling of the Bone Matrix. Methods Mol Biol 2021; 2230:303-323. [PMID: 33197021 PMCID: PMC9165628 DOI: 10.1007/978-1-0716-1028-2_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent advances have revived interest in the concept of osteocyte perilacunar/canalicular remodeling (PLR) and have motivated efforts to identify the mechanisms regulating this process in bone in the context of normal physiology and pathological conditions. Here, we describe several methods that are evaluating morphological changes associated with PLR function of osteocytes.
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Affiliation(s)
- Neha S Dole
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Cristal S Yee
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, USA
| | - Sarah L Dallas
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri Kansas City, Kansas City, MO, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA.
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, USA.
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10
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Heveran CM, Schurman CA, Acevedo C, Livingston EW, Howe D, Schaible EG, Hunt HB, Rauff A, Donnelly E, Carpenter RD, Levi M, Lau AG, Bateman TA, Alliston T, King KB, Ferguson VL. Chronic kidney disease and aging differentially diminish bone material and microarchitecture in C57Bl/6 mice. Bone 2019; 127:91-103. [PMID: 31055118 PMCID: PMC6760860 DOI: 10.1016/j.bone.2019.04.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 03/15/2019] [Accepted: 04/26/2019] [Indexed: 12/31/2022]
Abstract
Chronic kidney disease (CKD) is a common disease of aging and increases fracture risk over advanced age alone. Aging and CKD differently impair bone turnover and mineralization. We thus hypothesize that the loss of bone quality would be greatest with the combination of advanced age and CKD. We evaluated bone from young adult (6 mo.), middle-age (18 mo.), and old (24 mo.) male C57Bl/6 mice three months following either 5/6th nephrectomy, to induce CKD, or Sham procedures. CKD exacerbated losses of cortical and trabecular microarchitecture associated with aging. Aging and CKD each resulted in thinner, more porous cortices and fewer and thinner trabeculae. Bone material quality was also reduced with CKD, and these changes to bone material were distinct from those due to age. Aging reduced whole-bone flexural strength and modulus, micrometer-scale nanoindentation modulus, and nanometer-scale tissue and collagen strain (small-angle x-ray scattering [SAXS]. By contrast, CKD reduced work to fracture and variation in bone tissue modulus and composition (Raman spectroscopy), and increased percent collagen strain. The increased collagen strain burden was associated with loss of toughness in CKD. In addition, osteocyte lacunae became smaller, sparser, and more disordered with age for Sham mice, yet these age-related changes were not clearly observed in CKD. However, for CKD, larger lacunae positively correlated with increased serum phosphate levels, suggesting that osteocytes play a role in systemic mineral homeostasis. This work demonstrates that CKD reduces bone quality, including microarchitecture and bone material properties, and that loss of bone quality with age is compounded by CKD. These findings may help reconcile why bone mass does not consistently predict fracture in the CKD population, as well as why older individuals with CKD are at high risk of fragility.
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Affiliation(s)
- Chelsea M Heveran
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, United States of America
| | - Charles A Schurman
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, United States of America
| | - Claire Acevedo
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Eric W Livingston
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, United States of America
| | - Danielle Howe
- Department of Biomedical Engineering, The College of New Jersey, Ewing, NJ, United States of America
| | - Eric G Schaible
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - Heather B Hunt
- Department of Materials Science & Engineering, Cornell University, Ithaca, NY, United States of America
| | - Adam Rauff
- Department of Bioengineering, University of Colorado, Denver, CO, United States of America
| | - Eve Donnelly
- Department of Materials Science & Engineering, Cornell University, Ithaca, NY, United States of America
| | - R Dana Carpenter
- Department of Mechanical Engineering, University of Colorado, Denver, CO, United States of America
| | - Moshe Levi
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington D.C., United States of America
| | - Anthony G Lau
- Department of Biomedical Engineering, The College of New Jersey, Ewing, NJ, United States of America
| | - Ted A Bateman
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, United States of America
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, United States of America
| | - Karen B King
- Department of Orthopaedics, University of Colorado School of Medicine, Aurora, CO, United States of America
| | - Virginia L Ferguson
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, United States of America.
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Abstract
PURPOSE OF REVIEW In perilacunar/canalicular remodeling (PLR), osteocytes dynamically resorb, and then replace, the organic and mineral components of the pericellular extracellular matrix. Given the enormous surface area of the osteocyte lacuna-canalicular network (LCN), PLR is important for maintaining homeostasis of the skeleton. The goal of this review is to examine the motivations and critical considerations for the analysis of PLR, in both in vitro and in vivo systems. RECENT FINDINGS Morphological approaches alone are insufficient to elucidate the complex mechanisms regulating PLR in the healthy skeleton and in disease. Understanding the role and regulation of PLR will require the incorporation of standardized PLR outcomes as a routine part of skeletal phenotyping, as well as the development of improved molecular and cellular outcomes. Current PLR outcomes assess PLR enzyme expression, the LCN, and bone matrix composition and organization, among others. Here, we discuss current PLR outcomes and how they have been applied to study PLR induction and suppression in vitro and in vivo. Given the role of PLR in skeletal health and disease, integrated analysis of PLR has potential to elucidate new mechanisms by which osteocytes participate in skeletal health and disease.
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Affiliation(s)
- Cristal S Yee
- Department of Orthopaedic Surgery, University of California, 513 Parnassus Avenue, San Francisco, CA, 94143, USA
| | - Charles A Schurman
- Department of Orthopaedic Surgery, University of California, 513 Parnassus Avenue, San Francisco, CA, 94143, USA
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA
| | - Carter R White
- Department of Orthopaedic Surgery, University of California, 513 Parnassus Avenue, San Francisco, CA, 94143, USA
| | - Tamara Alliston
- Department of Orthopaedic Surgery, University of California, 513 Parnassus Avenue, San Francisco, CA, 94143, USA.
- UC Berkeley/UCSF Graduate Program in Bioengineering, San Francisco, CA, 94143, USA.
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12
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Moreau LM, Schurman CA, Kewalramani S, Shahjamali MM, Mirkin CA, Bedzyk MJ. How Ag Nanospheres Are Transformed into AgAu Nanocages. J Am Chem Soc 2017; 139:12291-12298. [DOI: 10.1021/jacs.7b06724] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liane M. Moreau
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Charles A. Schurman
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Sumit Kewalramani
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Mohammad M. Shahjamali
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Chad A. Mirkin
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael J. Bedzyk
- Department
of Materials Science and Engineering, ‡Department of Biomedical Engineering, §Department of Chemistry, ∥Department of Physics
and Astronomy, and ⊥International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
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