Biology subjects

Genever, P.

Publications and source records attributed to Genever, P..

4 recordsLinked to original sources

bioRxiv2026

Mechanoscribed Xolography for Multiscale Mechanical Patterning of Cell-laden Hydrogels

Mechanotransduction is a key regulator of healthy and malignant tissue development. However, current mechanobiological insights are largely derived from cells cultured on two dimensional substrates or in homogeneous biomaterials, which insufficiently capture the three dimensional (3D) heterogeneity and dynamic nature of the native extracellular matrix. This gap persists due to a lack of manufacturing processes and analysis modalities to control and monitor material properties and their evolution in 3D. Here, Mechanoscribed Xolography is introduced as a light sheet volumetric bioprinting process to rapidly fabricate 3D cell laden hydrogels with spatially controlled mechanical heterogeneity across multiple length scales. Moreover, synchronizing in-situ optical microscopy with printing enables autonomous detection and spatial location driven printing around cellular spheroids. The refinement and spatiotemporal evolution of material properties are assessed with Brillouin microscopy, which verifies that the contrast of imprinted heterogeneity is preserved over three weeks. Remarkably, regional differences in cell behavior are attained within a one-step, one-material construct with elasticity of approximately 0.3 kPa to 0.8 kPa, or 0.7 kPa to 2.9 kPa with a crosslinking-enhancing additive. This foundational work on high-precision, rapid bioprinting surrounding cellular objects represents a unique tool to systematically advance experimentation of 3D mechanotransduction and prospectively engineer cell instructive biomaterials for regenerative medicine.

bioengineering↗

bioRxiv2024

Extracellular vesicle bioactivity and potential clinical utility is determined by mesenchymal stromal cell clonal subtype

Mesenchymal stromal cells (MSCs) are a promising source of therapeutic extracellular vesicles (EVs), however it is not clear how heterogeneity within a non-clonal MSC population will affect the collective EV pool. Here we used immortalised clonal MSC lines, termed Y201 and Y202, to examine how MSC phenotype influences EV character and function. Although morphologically similar, Y201 EVs were more abundant in EV biomarkers versus Y202 EVs, with an enhanced miRNA and proteomic content, predicted to contribute to an elaborate EV corona particularly abundant in RGD-containing proteins fibronectin and MFG-E8. We demonstrated that Y201 EVs, but not Y202 EVs, significantly increased the proliferation of articular chondrocytes and that the proliferative effect was mediated at least in part via an RGD (integrin)-FAK-ERK1/2 axis. Both Y201 and Y202 EV subsets significantly reduced proliferative index scores of activated T cells. However, only Y201 EVs, not Y202 EVs, suppressed disease activity compared to controls in different in vivo models of inflammatory peritonitis and arthritis. EVs released by closely related MSC subtypes within the same heterogeneous population differ significantly in terms of cargo abundance, bioactivity, and pre-clinical in vivo efficacy. Analysis of defined EV subsets will aid mechanistic understanding and prioritisation for EV therapeutics.

cell biology↗

bioRxiv2023

Extracellular matrices of bone marrow stroma regulate cell phenotype and contribute to distinct stromal niches in vivo

The heterogeneity of bone marrow stromal cells (BMSCs) has been revealed more in recent years through the advent of single cell RNA sequencing. However, protein level characterisation is likely to provide a deeper understanding of the functions of individual subsets and may reveal insights into the co-ordination of the cell phenotype maintaining niche. Here, by analysing heterogeneity in BMSC populations using human stromal cell lines to model extremes of cell morphology and migration characteristics, we identified plastic cell phenotypes that can be modified through secreted proteins. Transfer of secreted signals from a differentiation-competent stem cell phenotype was able to stimulate migration in a slow-moving stromal cell, observed via label-free ptychography. Subsequent untargeted proteomic interrogation of the secreted factors from these cell lines identified a highly significant enrichment of extracellular matrix (ECM) protein production by the differentiation-competent cells compared to non-stem cells. The most highly enriched proteins, aggrecan and periostin, were identified on the endosteal surfaces of mouse and human bone, underlying CD271+ stromal cells in the latter, indicating that they may represent key non-cellular niche-components important for cell maintenance and phenotype. ECM from stem cells was further capable of enhancing migration in non-stem cells in a focal adhesion kinase-dependent manner. Overall, we demonstrate the importance of the ECM in co-ordination of cellular phenotype and highlight how non-cellular components of the BMSC niche may provide insights into the role of BMSCs in health and disease.

cell biology↗

bioRxiv2018

An immortalised mesenchymal stem cell line maintains mechano-responsive behaviour and can be used as a reporter of substrate stiffness

The mechanical environment can influence cell behaviour, including changes to transcriptional and proteomic regulation, morphology and, in the case of stem cells, commitment to lineage. However, current tools for characterizing substrates mechanical properties, such as atomic force microscopy (AFM), often do not fully recapitulate the length and time scales over which cells feel substrates. Here, we show that an immortalised, clonal line of human mesenchymal stem cells (MSCs) maintained responsiveness to substrate mechanics observed in primary cells, and could be used as a reporter of stiffness. MSCs were cultured on soft and stiff polyacrylamide hydrogels. In both primary and immortalised MSCs, stiffer substrates promoted increased cell spreading, expression of lamin-A/C and translocation of mechano-sensitive proteins YAP1 and MKL1 to the nucleus. Stiffness was also found to regulate transcriptional markers of lineage. A GFP-YAP / RFP-H2B reporter construct was designed and virally delivered to the immortalised MSCs for in situ detection of substrate stiffness. MSCs with stable expression of the reporter showed GFP-YAP to be increasingly co-localized with nuclear RFP-H2B on stiffer substrates, enabling development of a cellular reporter of substrate stiffness. This will facilitate mechanical characterisation of new materials developed for applications in tissue engineering and regenerative medicine.

bioengineering↗