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Collen, L.

Publications and source records attributed to Collen, L..

2 recordsLinked to original sources

A collection of patient-derived intestinal organoid lines reveals epithelial phenotypes associated with genetic drivers of pediatric inflammatory bowel disease

Pediatric Inflammatory Bowel Disease (IBD) is a chronic condition characterized by per-sistent intestinal inflammation in children and adolescents. Despite a rising global incidence, the underlying causes and optimal management strategies for pediatric IBD are still not fully understood. Compared to adult IBD, pediatric IBD frequently presents with distinct disease phenotypes, and is more commonly linked to rare monogenic variants that cause intestinal epithelial barrier dysfunction or affect the function of mucosal immune cells. While more than 100 genes have been associated with early-onset IBD, the roles of many of these genes in the intestinal epithelium and the mechanisms by which genetic variants contribute to disease remain poorly defined. Here we aimed to improve our understanding of intestinal epithelium dysfunction in early-onset IBD by conducting extensive molecular and cellular characterization to gain insights into patient-specific epithelial phenotypes and identify therapeutic targets. We generated intestinal epithelial organoids (IEOs) from 94 pediatric IBD patients, representing diverse clinical characteristics and including those with monogenic variants (BTK n=4, TTC7A n=3, IL10RA n=1, LRBA n=1, STXBP2 n=1, TTC37 n=1, TRNT1 n=1, PLCG2 n=1, DKC1 n=1, POLA1 n=1), and 46 non-IBD controls. This effort resulted in the largest RNA-seq dataset of pediatric IBD intestinal epithelial organoids to date, encompassing both baseline conditions and post-immunological stimulation, serving as a valuable resource for future research. We observed that IEOs effectively initiate inflammation upon stimulation with bacterial lysate, regardless of disease status, origin, or mutation status. Inflammatory stimulation triggered single-gene upregulation of IBD-linked SERPINA1 and LIFR across the IBD population compared to controls, suggesting their role in intestinal epithelial innate immune responses. However, co-expression network analysis showed no consistent transcriptional signatures across the entire IBD group at the systems level. Instead, differences emerged between controls and specific genotypes (TTC7A, STXBP2, LRBA), with STXBP2 and LRBA sharing an upregulated transcriptional response of IL-1 and SLC30-mediated zinc trafficking pathways. These findings underscore the potential of IEOs as a valuable model for studying IBD and offer key insights that could guide the development of targeted therapies for both monogenic and non-monogenic forms of IBD. O_FIG O_LINKSMALLFIG WIDTH=158 HEIGHT=200 SRC="FIGDIR/small/659052v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@10a4d9org.highwire.dtl.DTLVardef@b6cdadorg.highwire.dtl.DTLVardef@179216dorg.highwire.dtl.DTLVardef@181a4e4_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

Distinct heterozygous TTC7A missense variants lead to different intestinal epithelial phenotypes in pediatric IBD

Pathogenic mutations in Tetratricopeptide repeat domain 7A (TTC7A) result in gastrointestinal and immunological disorders of which the pathobiology is not fully understood. Previous case reports indicate that TTC7A plays an important role in preserving intestinal epithelial integrity, but thus far only few variants have been investigated and it is unclear if different variants exert the same effects. Here, we aim to study the effects of different variants on the intestinal epithelium. We present three instances of pediatric inflammatory bowel disease (IBD), displaying varying clinical symptoms and severity levels, and associated with different heterozygous missense mutations in TTC7A. Intestinal organoids derived from patients show dissimilar epithelial phenotypes and exhibit differences in growth, morphology, apicobasal polarity, responses to specific drugs, TTC7A expression, and transcriptional profiles. The findings of our study suggest differences in pathobiology between individuals with different TTC7A mutations. This investigation enhances our comprehension of TTC7A-related conditions and can have implications for developing targeted therapies for TTC7A-associated disorders.

genetics↗