Periodic Reporting for period 1 - MechanoHealing (Bone healing mechanomics in a mouse model of accelerated aging.)
Okres sprawozdawczy: 2022-09-01 do 2024-08-31
In over 100 years, the remarkable ability of bone to adapt to its mechanical environment has been a source of scientific fascination. Bone adapts to its mechanical environment by forming bone at sites of mechanical loading and resorbing bone at sites of mechanical unloading. Multiple cell types are recognized to be mechano-sensitive and respond to mechanical stimuli through the activation of specific molecular signalling pathways. Fracture healing has been shown to be highly dependent on the mechanical environment at the fracture site. It has been demonstrated that mechanical stimuli can either accelerate or impede healing.
Despite the fundamental importance of the mechanical environment in influencing fracture healing, the molecular mechanisms underlying this phenomenon are complex and poorly understood. This has prevented wider-scale harnessing of the mechano-sensitivity of the healing process in clinical applications. The use of mechanical intervention therapies to augment the healing response is of particular relevance in challenging fractures. Delayed bone healing or failed non-unions account for 5 – 10% of all bone fractures, presenting a significant challenge in regenerative medicine. Moreover, the prevalence of these challenging fractures is significantly greater in elderly populations. However, the field has yet to achieve consensus on whether bone exhibits age-associated declines in mechano-sensitivity.
The objectives of this project were: (i) to develop a molecular-based understanding of bone healing mechanobiology and (ii) to investigate how this mechano-sensitivity is compromised with age.
Despite the fundamental importance of the mechanical environment in influencing fracture healing, the molecular mechanisms underlying this phenomenon are complex and poorly understood. This has prevented wider-scale harnessing of the mechano-sensitivity of the healing process in clinical applications. The use of mechanical intervention therapies to augment the healing response is of particular relevance in challenging fractures. Delayed bone healing or failed non-unions account for 5 – 10% of all bone fractures, presenting a significant challenge in regenerative medicine. Moreover, the prevalence of these challenging fractures is significantly greater in elderly populations. However, the field has yet to achieve consensus on whether bone exhibits age-associated declines in mechano-sensitivity.
The objectives of this project were: (i) to develop a molecular-based understanding of bone healing mechanobiology and (ii) to investigate how this mechano-sensitivity is compromised with age.
To develop a molecular-based understanding of bone healing mechanobiology, a protocol to perform spatial transcriptomics in bone was established and published. Subsequently, the Fellow and colleagues at the host laboratory established a novel spatial transcriptomics based “mechanomics” approach to investigate the molecular mechanisms regulating bone mechanobiology. Spatial mechanomics represents a major technological achievement as it surpasses the current state-of-the-art in the field by permitting gene expression to be analysed as a function of the local mechanical environment. This new era of spatial mechanomics thus holds immense potential to answer fundamental questions within the field of bone mechanobiology – and substantially exceeds the scope of the project as it permits investigations into the molecular mechanisms governing the mechanical response of bone in the context of bone development, bone growth, bone adaptation, bone disease and bone regeneration.
To investigate the effects of aging on the mechanobiology of bone regeneration, the Fellow conducted in vivo studies in young and aged mice of both sexes. Cyclic mechanical loading significantly enhanced regeneration in young mice and this mechano-responsiveness was remarkably retained with aging across both sexes. Thus, these findings suggest mechanical therapies have potential in the treatment of challenging fractures in elderly patients of both sexes. To investigate the effects of sex and age on the molecular mechanisms regulating the response to mechanical stimuli at fracture sites, spatial transcriptomics experiments have been performed using the samples from the in vivo studies.
The methodologies developed and the results generated from the research conducted within the scope of this MSCA project are currently available as either (i) manuscripts on pre-print servers, or (ii) will form the contents of two additional manuscripts in preparation. Results have also been presented at orthopaedic and bone conferences in Europe and North America. In recognition of the significance of the research, the MSCA Fellow was an invited speaker at three eminent orthopaedic conferences during the course of his MSCA Fellowship. Social media posts via Twitter/X and LinkedIn have also contributed to the dissemination of the research.
Exploitation of the data generated has been as follows: The spatial transcriptomics data and the in vivo imaging data is being used within the host laboratory to develop novel computational pipelines to analyse “spatial mechanomics” data. Similarly, the in vivo imaging data is being used to develop in silico models of the regenerative process. Spatial transcriptomics data has been made available in public databases such that other research groups can profit from these unique datasets. Methodologies established during the Fellowship include a protocol to perform spatial transcriptomics in bone. This protocol represents one of the first successful demonstrations of the feasibility of performing spatial transcriptomics in bone. The protocol has now been published for the wider scientific community to benefit from it.
To investigate the effects of aging on the mechanobiology of bone regeneration, the Fellow conducted in vivo studies in young and aged mice of both sexes. Cyclic mechanical loading significantly enhanced regeneration in young mice and this mechano-responsiveness was remarkably retained with aging across both sexes. Thus, these findings suggest mechanical therapies have potential in the treatment of challenging fractures in elderly patients of both sexes. To investigate the effects of sex and age on the molecular mechanisms regulating the response to mechanical stimuli at fracture sites, spatial transcriptomics experiments have been performed using the samples from the in vivo studies.
The methodologies developed and the results generated from the research conducted within the scope of this MSCA project are currently available as either (i) manuscripts on pre-print servers, or (ii) will form the contents of two additional manuscripts in preparation. Results have also been presented at orthopaedic and bone conferences in Europe and North America. In recognition of the significance of the research, the MSCA Fellow was an invited speaker at three eminent orthopaedic conferences during the course of his MSCA Fellowship. Social media posts via Twitter/X and LinkedIn have also contributed to the dissemination of the research.
Exploitation of the data generated has been as follows: The spatial transcriptomics data and the in vivo imaging data is being used within the host laboratory to develop novel computational pipelines to analyse “spatial mechanomics” data. Similarly, the in vivo imaging data is being used to develop in silico models of the regenerative process. Spatial transcriptomics data has been made available in public databases such that other research groups can profit from these unique datasets. Methodologies established during the Fellowship include a protocol to perform spatial transcriptomics in bone. This protocol represents one of the first successful demonstrations of the feasibility of performing spatial transcriptomics in bone. The protocol has now been published for the wider scientific community to benefit from it.
The research outcomes benefit the field of bone mechanobiology and society in the following ways:
[1] The spatial mechanomics approach developed during the Fellowship represents a major technological achievement as it surpasses the current state-of-the-art in the field by permitting gene expression to be analysed as a function of the local mechanical environment. It thus presents unique opportunities to:
- Identify mechano-sensitive cells / anabolic pathways driving mechanical-induced bone healing.
- Identify new strategies and novel mechano-responsive targets to enhance repair in compromised healing environments.
- Facilitate the broader translation of mechano-therapeutics to clinical settings.
The approach has broad applicability within the field of bone mechanobiology. It has the potential to be applied to any skeletal site in any species or even adaptable for use with tissue engineered bone constructs. Furthermore, it has the potential to investigate mechano-molecular mechanisms in the context of bone development, bone growth, bone adaptation, bone disease and bone regeneration. Thus, it opens many avenues for future investigations.
[2] The prevalence of recalcitrant fractures is significantly greater in elderly populations. The Fellowship has generated insights into the effects of aging on the mechanobiology of bone regeneration. These insights include the finding that the mechano-responsive of bone after healing is remarkably retained with aging across both sexes. This suggests mechanical therapies have potential in the treatment of challenging fractures in elderly patients of both sexes. Further analyses at the cellular and molecular level are pending and are expected to further illuminate the role of the mechanical environment in aged bone.
[1] The spatial mechanomics approach developed during the Fellowship represents a major technological achievement as it surpasses the current state-of-the-art in the field by permitting gene expression to be analysed as a function of the local mechanical environment. It thus presents unique opportunities to:
- Identify mechano-sensitive cells / anabolic pathways driving mechanical-induced bone healing.
- Identify new strategies and novel mechano-responsive targets to enhance repair in compromised healing environments.
- Facilitate the broader translation of mechano-therapeutics to clinical settings.
The approach has broad applicability within the field of bone mechanobiology. It has the potential to be applied to any skeletal site in any species or even adaptable for use with tissue engineered bone constructs. Furthermore, it has the potential to investigate mechano-molecular mechanisms in the context of bone development, bone growth, bone adaptation, bone disease and bone regeneration. Thus, it opens many avenues for future investigations.
[2] The prevalence of recalcitrant fractures is significantly greater in elderly populations. The Fellowship has generated insights into the effects of aging on the mechanobiology of bone regeneration. These insights include the finding that the mechano-responsive of bone after healing is remarkably retained with aging across both sexes. This suggests mechanical therapies have potential in the treatment of challenging fractures in elderly patients of both sexes. Further analyses at the cellular and molecular level are pending and are expected to further illuminate the role of the mechanical environment in aged bone.