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Biology subjects

Mathavan, N.

Publications and source records attributed to Mathavan, N..

4 recordsLinked to original sources

The Mechanosensitivity of the Regenerative Response in Bone is Retained with Aging in a Mouse Model of Premature Aging.

Aging impairs the regenerative capacity of bone and is associated with poor healing outcomes. The mechanical environment is of fundamental importance to the regenerative response in bone - yet the effect of aging on the mechano-responsive capacity of bone regeneration remains largely unresolved. To investigate age-dependent mechanobiological responses in bone regeneration, we established an experimental framework consisting of: (i) an established femur defect mouse model, (ii) the use of PolgAD257A/D257A (PolgA) mice - a mouse model of premature aging, and (iii) our recently established spatial transcriptomics-based "mechanomics" platform which permits gene expression to be analyzed as a function of the local in vivo mechanical environment. Aging impaired the regenerative response in PolgA mice, resulting in an increased occurrence of delayed and non-unions, delayed bone formation / resorption responses, impaired osteogenesis and delayed mineralization of new bone. Cyclic mechanical loading significantly enhanced the regenerative response in young PolgA mice inducing sustained bone formation, suppressing bone resorption, and enhancing mineralization, with the strongest effects observed in peripheral regions of the fracture site. In aged PolgA mice, the mechanosensitivity of the regenerative response was retained with an anabolic response localized to the defect center. Cyclic mechanical loading applied during the reparative and remodelling phases of fracture healing thus represents a potential translational strategy to harness the mechanosensitivity of aged bone.

physiology↗

Spatial μProBe: a correlative multimodal imaging approach for spatial profiling of biological micro-environments

Despite fundamental advances in spatial omics, investigating cellular and molecular functions within their native environment remains a challenge in multiscale systems biology, especially in response to organ-level events. Here, we introduce Spatial {micro}ProBe (micro-ProBe), a multimodal imaging approach for spatial profiling of biological micro-environments. Spatial {micro}ProBe enables preprocessing, registration and correlative analysis of 2D and 3D imaging modalities, supported by an intuitive user interface. As an application, we investigated bone mechanobiology and characterised the cellular and molecular responses to mechanical loading during adaptation and regeneration, which continuously regulate the local microarchitecture. By integrating time-lapsed micro-computed tomography and end-point spatial transcriptomics, we profiled the local mechanical in vivo environment of thousands of musculoskeletal cells, revealing the spatiotemporal interplay between local mechanics and gene expression driving tissue development. Spatial {micro}ProBe marks a crucial advance in the characterisation of multiscale tissues and signalling, facilitating the exploration of targeted molecular therapies for pathological conditions.

systems biology↗

Spatial Transcriptomics in Mechanomics: New Horizons in Exploring the Mechanoregulation of Bone Regeneration

In recent decades, the field of bone mechanobiology has sought experimental techniques to unravel the molecular mechanisms governing the phenomenon of mechanically-regulated fracture healing. Each cell within a fracture site resides within different local micro-environments characterized by different levels of mechanical strain - thus, preserving the spatial location of each cell is critical in relating cellular responses to mechanical stimuli. Our spatial transcriptomics based "mechanomics" platform facilitates spatially-resolved analysis of the molecular profiles of cells with respect to their local in vivo mechanical environment by integrating time-lapsed in vivo micro-computed tomography, spatial transcriptomics, and micro-finite element analysis. We investigate the transcriptomic responses of cells as a function of the local strain magnitude by identifying the differential expression of genes in regions of high and low strain within a fracture site. Our platform thus has the potential to address fundamental open questions within the field and to discover mechano-responsive targets to enhance fracture healing.

physiology↗

Unveiling Frailty: Comprehensive and Sex-Specific Characterization in Prematurely Aging PolgA Mice

Frailty, a geriatric syndrome, is assessed using the frailty phenotype (FP) and frailty index (FI). While these approaches have been applied to aging mice, their effectiveness in prematurely aging mouse models such as PolgAD257A/D257A (PolgA) has not been completely explored. We demonstrated that frailty became evident in PolgA mice around 40 weeks, validated through body weight loss, reduced walking speed, decreased physical activity, and weaker grip strength. Moreover, we also identified sex differences in these mice with females exhibiting higher frailty compared to males. Frailty prevalence in PolgA mice at 40 weeks parallels that observed in naturally aging mice at 27 months and aging humans at 65-70 years. These findings contribute to understanding frailty onset and sex-specific patterns, emphasizing the significance of the PolgA mouse model in investigating aging and related disorders.

physiology↗