Biology subjects

Dalleywater, W.

Publications and source records attributed to Dalleywater, W..

3 recordsLinked to original sources

bioRxiv2025

Intestinal Stem and Progenitor Cells Exhibit Distinct Adaptive Responses to Inflammatory Stress in IBD

BackgroundIntestinal epithelial stem cells (SCs) and their transit-amplifying (TA) progeny are critical for mucosal repair and regeneration. However, their behaviour under chronic inflammatory conditions, such as those observed in Inflammatory Bowel Disease (IBD), remains incompletely understood. MethodsWe investigated the impact of chronic inflammation on intestinal stem/progenitor cells by integrating bulk RNA sequencing from the largest IBD biopsy cohort to date with single-cell transcriptomic analysis and experimental assays using patient-derived intestinal organoids. ResultsActive inflammation was associated with a reduction in canonical LGR5 intestinal stem cells and a concurrent expansion of OLFM4 populations, consistent with an inflammation-induced epithelial repair program. Notably, SC/TA cells from both inflamed and non-inflamed IBD tissues exhibited persistent transcriptional changes that were distinct from those in healthy controls. Single-cell analysis identified transcriptionally heterogeneous SC/TA subpopulations, including a previously uncharacterized inflammation-associated cluster enriched in immune signalling pathways. Pseudotime trajectory analysis demonstrated a shift in differentiation toward deep crypt secretory (Paneth-like) cell lineages under inflammatory conditions. ConclusionsChronic intestinal inflammation reshapes the epithelial stem and progenitor cell compartment, promoting altered differentiation and the emergence of immune-responsive epithelial states. These findings highlight the plasticity of the human intestinal epithelium in IBD and point to new avenues for therapeutic strategies aimed at maintaining epithelial integrity during chronic inflammation.

molecular biology↗

bioRxiv2023

A rapid method for generating transplantable and biologically responsive colonic tissue from human induced pluripotent stem cells.

BackgroundThe colonic mucosa consists of cell populations derived from multiple lineages. Induced pluripotent stem cells (iPSCs) are capable of generating large numbers of differentiated cells from any lineage. Thus, iPSCs are highly versatile for derivation of intestinal cells for generation of colonic mucosal tissue for clinical and biological applications. ObjectiveWe set out to create a human iPSC (hiPSC) multi-lineage co-differentiation platform capable of generating colonic mucosal tissue in vitro. DesignWe used hiPSCs and designed a differentiation protocol consisting of small molecules and recombinant growth factors to generate multiple cell lineages. Cells were seeded onto collagen hydrogels (forming colonic patches - CoPs) and modulated with multiple growth factors important in intestinal biology. CoPs were transplanted into immunosuppressed mice. Generated cells and tissues were profiled with transcriptomic analysis. ResultshiPSC co-differentiation led to multiple intestinal epithelial, mesenchymal and endothelial cell populations. Seeded onto collagen scaffolds these cells created CoPs, which were transplanted into mouse subcutis. Engrafted CoPs developed into normal-looking colonic mucosa containing epithelial crypts (with enterocytes, goblet cells and neuroendocrine cells), multiple lamina propria-resident stromal populations and muscularis mucosae smooth muscle. They anastomosed to murine vasculature and maintained in-vitro for several weeks. We demonstrated that CoPs respond to known signalling pathways important in colonic mucosal biology and fibrogenesis, showing potential to provide a complex model of colonic pathobiology. ConclusionThis platform could offer an accurate model of intestinal pathobiology, supply cells for regenerative cell therapies to treat intestinal disease, and provide therapeutic autologous grafts to repair damaged colon.

cell biology↗

bioRxiv2021

N-glycosylation of CD24 mediates cell motility but inhibits cell proliferation in colorectal cancer

CD24 confers features of stemness and enhances cell motility in colorectal cancer. It contains numerous O-glycosylation sites but just two putative N-glycosylation sites. The study aimed to mutate N-glycosylation as it thought to be important in mediating many glycoproteins function. Site-directed mutagenesis performed to mutate N-glycosylation sites by converting asparagine residues to glutamine. Each site was mutated individually (CD24N36Q and CD24N52Q) and in combination (CD24N[36,52]Q) and were overexpressed in HCT116 and SW480 cell lines. The effect of the mutant CD24 on cell viability, cell motility and induction of downstream targets was compared to wild-type CD24 and empty vector control (EVC). Overexpression of the individually mutated clones increased cell motility compared to EVC but was significantly less than that induced by CD24WT. Overexpression of the double mutant clone resulted in near-complete abrogation of cell motility induction. Unexpectedly, the expression of mutant clones (single and double) increased cell viability. Analysis of downstream targets and F-actin staining demonstrated reduced induction of known CD24 targets by mutant vectors and reduced epithelial-mesenchymal transition. In conclusion, each N-glycosylation site on CD24 contributes partially to induce motility by CD24, and these are additive. Loss of the N-glycosylation results in an unexpected gain of proliferative function. HighlightsO_LICD24 is a heavily glycosylated molecule that contains two N-glycosylation sites, and these contribute to the activation of downstream targets and induction of cell motility C_LIO_LIEach N-glycosylation site contributes partially, and their effects appear to be additive C_LIO_LIThe N-glycosylation sites may exert an inhibitory effect on cell proliferation C_LIO_LIMuch of the CD24 activity is mediated through post-transcriptional effects C_LI

cancer biology↗