Biology subjects

Rowley, L.

Publications and source records attributed to Rowley, L..

4 recordsLinked to original sources

bioRxiv2025

Application of spatial transcriptomics across organoids: a high-resolution spatial whole-transcriptome benchmarking dataset

Stem cell-derived organoids hold promise to model tissue-specific disease. To enable this, it is crucial to assess how transcriptional signatures, cellular organisation and composition of organoids compare to in vivo counterparts. However, technologies which elucidate regional molecular identity, like spatial transcriptomics, have been challenging to apply to organoids. This study presents the first systematic profiling of multiple stem cell derived organoid models (brain, heart muscle, heart valve, kidney, lung, cartilage, and haematopoietic) with Stereo-seq, a full transcriptome, spatial transcriptomics assay using on-chip in situ RNA capture at subcellular resolution. It describes optimisation of this assay to characterise organoids, use of multiple organoid samples on a single chip, assess differences in RNA capture efficiency compared to reference tissues and its limitations. This study introduces a bespoke analysis method that partitions samples into regions and further characterises them. These findings inform future works to characterise organoids using spatial transcriptomics, providing insights in optimising RNA capture of multiple organoids across a chip and novel methods for regional analysis.

bioinformatics↗

bioRxiv2022

The effect of carbamazepine on bone structure and strength in control and Osteogenesis Imperfecta (Col1a2 +/p.G610C) mice

The inherited brittle bone disease osteogenesis imperfecta (OI) is commonly caused by COL1A1 and COL1A2 mutations that disrupt the collagen I triple helix. This causes intracellular endoplasmic reticulum (ER) retention of the misfolded collagen and can result in a pathological ER stress response. A therapeutic approach to reduce this toxic mutant load could be to stimulate mutant collagen degradation by manipulating autophagy and/or ER-associated degradation. Since carbamazepine (CBZ) both stimulates autophagy of misfolded collagen X and improves skeletal pathology in a metaphyseal chondrodysplasia model, we tested the effect of CBZ on bone structure and strength in 3 week-old male OI Col1a2 +/p.G610C and control mice. Treatment for 3 or 6 weeks with CBZ, at the dose effective in metaphyseal chondrodysplasia, provided no therapeutic benefit to Col1a2 +/p.G610C mouse bone structure, strength, or composition, measured by micro-computed tomography, three point bending tests and Fourier-transform infrared microspectroscopy. In control mice however, CBZ treatment for 6 weeks impaired femur growth and led to lower femoral cortical and trabecular bone mass. These data, showing the negative impact of CBZ treatment on the developing mouse bones, raise important issues which must be considered in any human clinical applications of CBZ in growing individuals.

pathology↗

bioRxiv2021

XBP1s-Mediated Endoplasmic Reticulum Proteostasis Network Enhancement Can Selectively Improve Folding and Secretion of an Osteogenesis Imperfecta-Causing Collagen-I Variant

Osteogenesis imperfecta (OI) is typically caused by autosomal dominant mutations in genes encoding collagen type-I, most commonly resulting in Gly[->]Ser triple-helical domain substitutions that disrupt collagen folding and/or stability. Here, we test the hypothesis that upregulating the endoplasmic reticulum (ER) proteo-stasis network via the unfolded protein response (UPR) can improve the folding and secretion of the clinically severe, prototypical OI-causing COL1A1 p.G425S collagen-1(I) variant. We first show that small molecules that activate the entire UPR by causing global ER protein misfolding stress severely ablate collagen-I secretion from both G425S Col1(I)- and wild-type (WT) Col1(I)-expressing primary fibroblasts. In contrast, stress-independent, specific induction of just the UPRs XBP1s transcriptional response can enhance collagen-I secretion from G425S Col1(I) patient primary fibroblasts up to ~300% of basal levels. Notably, the effect is selective - collagen-I secretion from WT Col1(I)-expressing healthy donor primary fibroblasts is unaltered by XBP1s. XBP1s pathway activation appears to post-translationally enhance the folding/assembly and secretion of G425S Col1(I), as only modest impacts on collagen-I transcription or synthesis are observed. Consistent with this notion, we find that the stable, triple-helical collagen-I secreted by XBP1s-activated G425S 1(I) patient fibroblasts includes a higher proportion of the mutant 1(I) polypeptide than the collagen-I secreted under basal ER proteostasis conditions. We note that consistent reproducibility of these results is dependent on as yet unascertained experimental variables. Still, these promising observations suggest the potential for ER proteo-stasis network modulation to improve mutant collagen proteostasis in the collagenopathies, motivating further investigation of the effects generality, underlying mechanism, and potential therapeutic benefits.

cell biology↗

bioRxiv2017

Cartilage microRNA dysregulation during the onset and progression of mouse osteoarthritis overlaps with patient disease candidates

To explore the role of microRNAs in osteoarthritis (OA), we conducted microRNA expression profiling on micro-dissected tibial cartilage and subchondral bone in a mouse model of OA produced by medial meniscus destabilization (DMM). DMM mice had characteristic cartilage degeneration, subchondral bone sclerosis and osteophyte formation. While subchondral bone showed no microRNA dysregulation, 139 microRNAs were differentially expressed in DMM cartilage at 1 and/or 6 weeks after OA initiation. To prioritize OA-candidates, dysregulated microRNAs with human orthologues were filtered using paired microRNA:mRNA expression analysis to identify those with corresponding changes in mRNA target transcripts in the DMM cartilage. An important cohort overlapped with microRNAs identified in human end-stage OA. Comparisons with microRNAs dysregulation in DMM mouse cartilage where aggrecan cleavage was genetically-ablated demonstrated that all were independent of aggrecan breakdown, earmarking these as important to the critical stages of OA initiation. Our comprehensive analyses identified high-priority microRNA candidates that have potential as human OA-biomarkers and therapeutic targets.\n\nSUMMARYKung et al. conducted global analysis of microRNA dysregulation in joint tissues of a well-established mouse osteoarthritis model. Stringent filtering against human microRNA orthologues, integrated mRNA target analysis and comparison with published studies on human end-stage osteoarthritis identified microRNA candidates of potential clinical relevance.

cell biology↗