Biology subjects

Grover, L. M.

Publications and source records attributed to Grover, L. M..

5 recordsLinked to original sources

bioRxiv2026

Elevated hydrostatic pressure modulates endothelial junctional mechanotransduction through VE-cadherin remodelling and altered association with YAP1, EPS8: an endothelium-on-chip study

Endothelial dysfunction is a hallmark of numerous vascular pathologies and is strongly influenced by mechanobiological forces within the vascular microenvironment. While the effects of shear stress have been extensively investigated, the mechanisms by which elevated hydrostatic pressure regulates endothelial junctional organisation remain sparsely investigated. Here, we employed a microfluidic platform to investigate the combined effects of low shear stress (1.4 dyne/cm2) and elevated hydrostatic pressure (~3972 Pa) on endothelial junctional dynamics. Elevated hydrostatic pressure induced marked remodelling of VE-cadherin junctions, characterised by formation of serrated, finger-like structures accompanied by increased YAP1 nuclear localisation and reduced YAP1-VE-cadherin cytoplasmic colocalisation compared to shear stress alone conditions. Further, elevated hydrostatic pressure also demonstrated an increase in cytoplasmic accumulation of EPS8, an actin adaptor protein, and increased cytoplasmic EPS8-VE-cadherin colocalisation. These observations were accompanied by functional changes marked by increased endothelial permeability, and enhanced THP-1 monocyte adhesion, thus suggesting activation of mechanosensitive pathways linked to dynamic junctional reorganisation. Inhibition of PI3K at elevated hydrostatic pressure exhibited a thin VE-cadherin patterning and increased cytoplasmic EPS8-VE-cadherin colocalisation, thus demonstrating a prominent role for PI3K signalling in regulating the junction organisation. Interestingly, Piezo-1 activation using Yoda1 produced context-dependent effects. Under shear stress alone, Yoda1 promoted YAP1 nuclear translocation, reduced YAP1-VE-cadherin colocalisation, increased endothelial permeability but strikingly did not impact THP-1 adhesion compared to shear stress alone conditions. In contrast, under elevated hydrostatic pressure conditions, Yoda1 significantly reduced both endothelial permeability and THP-1 adhesion while increasing YAP1-VE-cadherin colocalisation and decreasing YAP1 nuclear accumulation. Collectively, these findings identify a previously underappreciated elevated hydrostatic pressure-Piezo-1-PI3K signalling axis that regulates endothelial barrier integrity and pro-adhesive endothelial activation through coordinated regulation of VE-cadherin, YAP1, and EPS8. These results highlight elevated hydrostatic pressure as a unique mechanobiological stimulus, distinct from that of shear stress alone and provide novel insights into mechanisms underlying microvascular dysfunction.

bioengineering↗

bioRxiv2026

Engineering an in vitro spinal column: Manufacturing designs and emerging solutions for producing an axial mechanobiological system

The human spine is a complex, coordinated biomechanical system. Physiologically, its tissues are also highly interdependent in terms of function and viability. The interaction between mechanical stress and biological/biochemical activity over time constitutes a key driver of spinal degeneration. Research to date providing mechanistic insights into this process has focused on individual components (vertebra and disc tissue analogues), in isolation or as basic functional units. However, many observations from individual units will not translate to whole spine behaviour. The intricate complexity of the spine requires novel experimental models (synthetic and biotic), which must consider the spine at an organ level and adopt an integrative approach that can capture the dynamics which govern its function. Here, we report the development of a biomimetic spinal model prototype, amenable to cellular integration, which is miniaturised to the in vitro scale to provide a controlled environment and testbed for axial biological mechanics. The research presented here encompasses more than a decade of systematic investigations during which the gradual emergence of key manufacturing innovations progressively enabled addressing an exceptionally complex bioengineering challenge - organotypic spine engineering. The model comprises the full anatomical range of spinal vertebrae/bones (C1 to Sacrum & Coccyx), reproduced using bioceramic materials, assembled in sequence into a relevant columnar architecture and mechanically connected end-to-end by biochemically active interfaces. A range of assessments examining anatomical design, material behaviour and manufacturing processes is presented. The work explores concepts such as longitudinal mechanobiology and multi-segment coupling as well as manufacturing strategies using autonomous materials and instrumentation. This prototype introduces for the first time columnar level behaviour and the ability to study time dependent adaptations. This model is important because it can support tissue maturation, evolving mechanical properties and adaptive behaviour and it represents an intermediate step between isolated skeletal tissue models and future organ-level spinal constructs.

bioengineering↗

bioRxiv2025

Elevated hydrostatic pressure acts via piezo-1 to destabilise VE-cadherin junctions: an endothelium-on-chip study

Despite the effects of shear stress on endothelial biology having been extensively researched, the effects of hydrostatic vascular pressure at extremely low shear stresses have been largely ignored. In the current study, we employ a microfluidic organ-on-chip platform to elucidate the time and shear stress dependent effects of elevated hydrostatic pressure on endothelial junctional perturbations. We report that short term (1h) exposure to elevated hydrostatic pressure at high shear stress (1 dyne/cm2) but not low shear stress (0.1 dyne/cm2) caused VE-cadherin to form serrated, finger like projections at the cell-cell junctions and this effect was abrogated upon pharmacologically inhibiting piezo-1 mechanosensory protein. Interestingly, prolonged exposure (24h) to elevated hydrostatic pressure at low (0.1 dyne/cm2) but not high shear stress (1 dyne/cm2) caused VE-cadherin internalisation, thereby increasing the cytoplasmic concentration. Further, we report that this internalisation of VE-cadherin was reversible upon pharmacologically inhibiting piezo-1 in a time-dependent manner wherein after 12h, we observed stable VE-cadherin junctions re-appear at the cell-cell junctions. Overall, we demonstrate that piezo-1 plays a crucial role in the mechanotransduction of elevated hydrostatic pressure by regulating the VE-cadherin dynamics at cell-cell junctions. Targeting piezo-1 may provide a novel therapeutic/diagnostic marker, especially in conditions that involve microvascular dysfunction due to elevated vascular pressures.

bioengineering↗

bioRxiv2020

Alterations in excitatory and inhibitory synaptic development within the mesolimbic dopamine pathway in a mouse model of prenatal drug exposure

The rise in rates of opioid abuse in recent years has led to an increase in the incidence of neonatal abstinence syndrome (NAS). Despite having a greater understanding of NAS and its symptoms, there still remains a lack of information surrounding the long-term effects of prenatal exposure to drugs of abuse on neurological development. One potential outcome of prenatal drug exposure that has been increasingly explored is disruption in normal synaptogenesis within the central nervous system. Both opioids and gabapentin, an antiepileptic drug commonly co-abused by opioid abuse disorder patients, have been shown to interfere with the normal functioning of astrocytes, non-neuronal glial cells known to serve many functions, including regulation of synaptic development. The goal of this study was to investigate the effects of prenatal drug exposure on synaptogenesis within brain regions associated with the mesolimbic dopamine pathway, the primary reward pathway within the brain associated with drug abuse and addiction, in a pregnant mouse model. Immunohistochemistry (IHC) and confocal fluorescence microscopy imaging studies on the brains of postnatal day 21 (P21) mouse pups revealed a significant increase in the mean number of excitatory synapses within the anterior cingulate cortex (ACC), nucleus accumbens (NAc), and prefrontal cortex (PFC) in mice that were prenatally exposed to either the opioid drug buprenorphine or gabapentin. These studies also revealed a significant decrease in the mean number of inhibitory synapses within the NAc and PFC of mice treated with buprenorphine. This observed net increase in excitatory signaling capability within the developing mesolimbic dopamine pathway suggests that exposure to drugs of abuse in utero can trigger maladaptive neuronal connectivity that persists beyond the earliest stages of life.

neuroscience↗

bioRxiv2020

Formulation of a composite nasal spray enabling enhanced surface coverage and prophylaxis of SARS-COV-2

Airborne pathogens pose high risks in terms of both contraction and transmission within the respiratory pathways, in particular the nasal region. Although knowledge of airborne transmission has long been known, there is little in the way of adequate intervention that can protect the individual, or even prevent further spread. This study focuses on a nasal applicant with the capacity to combat such issues, by focussing on the SARS-CoV-2 virus. Formulation of a spray containing polysaccharides known for their mucoadhesive properties was undertaken and characterised for their mechanical, spray patterns and antiviral properties. The ability to engineer key behaviours such as yielding have been shown, through systematic understanding of a composite mixture containing two polymers: gellan and {lambda}carrageenan. Furthermore, spray systems demonstrated highly potent antiviral capacities, resulting in complete inhibition of the virus when studied for both prophylaxis and prevention of spread. Finally, a mechanism has been proposed to explain such findings. Therefore, demonstrating the first fully preventative device, targeted to protect the lining of the upper respiratory pathways.

bioengineering↗