Biology subjects

Wilkins, B. J.

Publications and source records attributed to Wilkins, B. J..

4 recordsLinked to original sources

bioRxiv2025

FOXM1 Modulation Alleviates Epithelial Remodeling and Inflammation in Eosinophilic Esophagitis

BackgroundEosinophilic esophagitis (EoE) is a chronic allergic disease characterized by esophageal epithelial remodeling, barrier dysfunction, and inflammation. Despite histologic remission, molecular and structural changes in the epithelium persist, contributing to ongoing symptoms and relapse. The transcription factor FOXM1 has been shown to be a key regulator of epithelial proliferation and inflammation in allergic asthma. ObjectiveTo investigate the role of FOXM1 in epithelial disruption in EoE and to evaluate the therapeutic potential of FOXM1 inhibition. DesignFOXM1 expression was analyzed in human esophageal biopsies, patient-derived organoids, and murine EoE models. IL-13 stimulation was used to model EoE in vitro. The effects of FOXM1 inhibition via the small molecule RCM-1 and siRNA-mediated knockdown were assessed by histology, gene expression profiling, organoid formation rates, and barrier integrity assays. RNA sequencing and chromatin immunoprecipitation were performed to elucidate molecular mechanisms. ResultsFOXM1 was significantly upregulated in patients with active EoE and localized to the basal epithelium. IL-13 increased FOXM1 expression, which impaired epithelial differentiation and enhanced basal cell hyperplasia. FOXM1 inhibition restored differentiation markers, reduced basal hyperplasia, and improved barrier function. In murine models, RCM-1 ameliorated epithelial changes and decreased eosinophil infiltration. Mechanistically, FOXM1 directly regulated cell cycle gene, CCNB1, which was upregulated in EoE and downregulated upon FOXM1 inhibition. FOXM1 expression was driven by an IL-13-PI3K/AKT axis. ConclusionFOXM1 plays a pivotal role in epithelial disruption in EoE by driving proliferation and impairing differentiation. Targeting FOXM1 restores epithelial homeostasis, mitigates inflammation, and offers a novel therapeutic approach for EoE. Key MessagesWhat is already known on this topic: Eosinophilic esophagitis is marked by epithelial remodeling and barrier dysfunction driven by Th2 inflammation. Despite remission, molecular and histologic changes in the esophageal epithelium persist, contributing to symptoms and relapse. The mechanisms underlying this epithelial dysregulation remain poorly understood. What this study adds: This study identifies FOXM1 as a key transcriptional regulator of epithelial disruption in EoE, demonstrating that FOXM1 inhibition restores epithelial differentiation, reduces basal cell hyperplasia, improves barrier integrity, and mitigates inflammation. How this study might affect research, practice, or policy: Targeting FOXM1 offers a novel therapeutic strategy to restore epithelial homeostasis and reduce inflammation in EoE. This dual approach, addressing both epithelial and immune dysregulation, may guide future therapeutic development and improve patient outcomes.

molecular biology↗

bioRxiv2023

METTL3 is essential for small intestinal epithelial proliferation via regulation of growth factor signaling including KRAS

Intestinal epithelial transit amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite their critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit amplifying cell function. We report that the RNA methyltransferase, METTL3, is required for survival of transit amplifying cells in the murine small intestine. Transit amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Ribosome profiling and sequencing of methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of unique methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation confirmed a novel relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine, with important implications for both homeostatic tissue renewal and epithelial regeneration.

cell biology↗

bioRxiv2020

Interaction of RSC chromatin remodelling complex with nucleosomes is modulated by H3 K14 acetylation and H2B SUMOylation in vivo

Chromatin remodelling complexes are multi-subunit nucleosome translocases that reorganize chromatin in the context of DNA replication, repair and transcription. A key question is how these complexes find their target sites on chromatin. Here, we use genetically encoded photo-crosslinker amino acids to map the footprint of Sth1, the catalytic subunit of the RSC (remodels the structure of chromatin) complex, on the nucleosome in living yeast. We find that the interaction of the Sth1 bromodomain with the H3 tail depends on K14 acetylation by Gcn5. This modification does not recruit RSC to chromatin but mediates its interaction with neighbouring nucleosomes. We observe a preference of RSC for H2B SUMOylated nucleosomes in vivo and show that this modification moderately enhances RSC binding to nucleosomes in vitro. Furthermore, RSC is not ejected from chromatin in mitosis, but its mode of nucleosome binding differs between interphase and mitosis. In sum, our in vivo analyses show that RSC recruitment to specific chromatin targets involves multiple histone modifications most likely in combination with other components such as histone variants and transcription factors. Key PointsO_LIIn vivo photo-crosslinking reveals the footprint of the ATPase subunit of RSC on the nucleosome. C_LIO_LIRSC binds to H3 K14ac nucleosomes via the C-terminal bromodomain of its ATPase-subunit Sth1. C_LIO_LIRSC preferentially localizes to H2B-SUMOylated nucleosomes. C_LI

biochemistry↗

bioRxiv2018

Posttranscriptional regulation of intestinal epithelial cell repair by RNA binding protein IMP1

RNA binding proteins, such as IMP1, are emerging as essential regulators of intestinal development and cancer. IMP1 hypomorphic mice exhibit severe intestinal growth defects, yet its role in adult intestinal epithelium is unclear. We employed ribosome profiling to test the effect of IMP1 loss on the \"translatome\" in colon cancer cell lines. In parallel, we evaluated mice with intestinal epithelial-specific Imp1 deletion (Imp1{Delta}IEC) following irradiation or colitis models. Ribosome-profiling revealed translation efficiency changes for multiple pathways important for intestinal homeostasis, including autophagy, in IMP1 knockout cells. We found increased autophagy flux in Imp1{Delta}IEC mice, reinforced through in silico and biochemical analyses revealing direct binding of IMP1 to autophagy transcripts MAP1LC3B and ATG3. We found that Imp1{Delta}IEC mice exhibit enhanced recovery following irradiation, which is attenuated with genetic deletion of autophagy gene Atg7. Finally, we demonstrated that IMP1 is upregulated in Crohns disease patients and Imp1 loss lessened colitis severity in mice. These studies demonstrate that IMP1 acts as a posttranscriptional regulator of gut epithelial repair post-irradiation and colitis, in part through modulation of autophagy.

physiology↗