Biology subjects

Riley, L. G.

Publications and source records attributed to Riley, L. G..

3 recordsLinked to original sources

bioRxiv2026

Early AAV9-mediated SLC9A6 gene replacement preserves cerebellar structure and motor function in the shaker rat model of Christianson syndrome

Christianson syndrome (CS) is an X-linked neurodevelopmental and neurodegenerative disorder caused by SLC9A6 loss of function, resulting in NHE6 deficiency and epilepsy, intellectual disability, cerebellar atrophy, and ataxia. Following on our prior gene replacement therapeutic development, we preclinically evaluated AAV9-mediated SLC9A6 gene replacement in the context of promoter selection, dosing, and treatment timing. Intracerebroventricular delivery of neuronal-targeted gene replacement at 1 x 10^11 vector genomes (vg) produced substantial improvements in motor coordination and preserved cerebellar volume, quantified through structural MRI. Early postnatal treatment prevented the development of gait ataxia throughout the longitudinal assessment period, statistically indistinguishable from wildtype controls, with molecular analyses demonstrating restored NHE6 expression and preservation of cerebellar markers. Interestingly, later treatments at timepoints corresponding to early neurodegenerative stages yielded strong initial effects, but these effects were largely lost over time, with half-life modelling demonstrating the need for early treatment. This conflicted with more persistent motor benefit shown in prior work with an engineered capsid, suggesting the need to consider the interaction between treatment timing and capsid-specific tropism and/or persistence. Finally, we built models capable of accurately predicting motor coordination from several protein markers. These findings will impact therapeutic development for CS, with relevance across neurodevelopmental genetic disorders.

neuroscience↗

bioRxiv2026

Functional Assessment of Cardiac Beat Dynamics Under Dynamic Flow: Insights from the Mera Microphysiological System

Cardiac rhythm is a critical clinical indicator for cardiac arrhythmias and adverse events during drug toxicity studies. In vivo, cardiomyocyte responses to pharmacological agents occur within minutes and are strongly influenced by dynamic drug delivery through blood flow. However, conventional 2D and 3D static culture systems fail to replicate these fluid flow kinetics, limiting their physiological relevance for assessing beat rate responses. Here, we present Mera, an advanced microphysiological system (MPS) developed by Hooke Bio, designed for high-throughput, long-term culture and functional analysis of 3D cardiac spheroids composed of human induced pluripotent stem cell-derived cardiomyocytes and cardiac fibroblasts. Mera enables dynamic perfusion, allowing investigation of cardiomyocyte beat rates under physiologically relevant flow conditions. The platform supports up to 640 spheroids per run and integrates automated imaging, fluid handling, and user-friendly software, operating under controlled physiological conditions (37{degrees}C, 5% CO2). Flow rates are tunable between 0 and 12.5 mL/min to mimic in vivo environments. Pharmacological testing with verapamil, isoproterenol, calcium chloride, and propranolol demonstrated real-time, reversible modulation of beat rate under flow, including recovery following drug-induced suppression. System variability was comparable to a temperature-controlled reference platform, supporting robust statistical analysis. Dose-response studies yielded IC values consistent with literature, confirming physiological relevance. Collectively, these results demonstrate that Mera provides a reproducible, scalable, and human-relevant platform for cardiac drug testing. By enabling dynamic drug exposure and automated analysis, Mera represents a powerful new approach methodology (NAM) for improving the predictive assessment of cardiac safety and beat-rate modulation drug responses.

bioengineering↗

bioRxiv2020

A novel RLIM/RNF12 variant disrupts protein stability and function to cause severe Tonne-Kalscheuer syndrome

Tonne-Kalscheuer syndrome (TOKAS) is an X-linked intellectual disability syndrome associated with variable clinical features including craniofacial abnormalities, hypogenitalism and diaphragmatic hernia. TOKAS is caused exclusively by variants in the gene encoding the E3 ubiquitin ligase gene RLIM, also known as. Here we report identification of a novel RLIM missense variant, c.1262A>G p.(Tyr421Cys) adjacent to the regulatory basic region, which causes a severe form of TOKAS resulting in perinatal lethality by diaphragmatic hernia. Inheritance and X-chromosome inactivation patterns implicate RLIM p.(Tyr421Cys) as the likely pathogenic variant in the affected individual and within the kindred. We show that the RLIM p.(Tyr421Cys) variant disrupts both expression and function of the protein in an embryonic stem cell model. RLIM p.(Tyr421Cys) is correctly localised to the nucleus, but is readily degraded by the proteasome. The RLIM p.(Tyr421Cys) variant also displays significantly impaired E3 ubiquitin ligase activity, which interferes with RLIM function in Xist long-non-coding RNA induction that initiates imprinted X-chromosome inactivation. Our data uncover a highly disruptive missense variant in RLIM that causes a severe form of TOKAS, thereby expanding our understanding of the molecular and phenotypic spectrum of disease severity.

developmental biology↗